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Frontiers in Crystalline Matter: From Discovery to Technology 3 The Status of Activities in the Discovery and Growth of Crystalline Materials To provide a complete picture of the status of activities in the discovery and growth of crystalline materials (DGCM) in the United States and internationally, the committee reviewed six areas that affect the field: education and training in DGCM; the role of industry; innovation and discovery; the breadth and depth of research; support for DGCM activities; and international activities. These areas are discussed further in this chapter. EDUCATION AND TRAINING The discovery and growth of crystalline materials and the scientific and technological enterprises dependent on them can only flourish if the field has a steady supply of young scientists educated in the cross-disciplinary science associated with the field and trained in the specialized techniques necessary for success in the field. To assess the state of education and training in the DGCM in the United States, the committee consulted with leaders in the field, including officers of the American Association for Crystal Growth and of the American Crystallographic Society. It also conducted surveys both of prominent crystal growers and of scientists who have only recently entered the field. Finally, it gathered information from public hearings and other sources. According to the information collected, the consensus of those in the crystal-growing community is that education in crystal growth and crystalline materials discovery is achieved through an apprenticeship model: graduate students are trained at universities by researchers in the field and then have postgraduate opportunities available to develop their skills further. However,
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Frontiers in Crystalline Matter: From Discovery to Technology the decrease in basic research at large industrial research laboratories, shifts in federal funding, and the organization of university research by discipline have all contributed to a marked decline in the availability of educational and training opportunities in the United States in this vital area; meanwhile, such opportunities elsewhere are increasingly available. Before considering these causes and effects in more detail, it should be noted that the impact of DGCM extends well beyond the traditional fields of physics, chemistry, and materials science, influencing many diverse fields. In biology, for example, crystal growers seek to understand biomineralization and biological control of crystal growth, while in geochemistry researchers seek to understand molecular-scale processes as they relate to geological processes. However, this report focuses only on crystal growth and new materials discovery as they manifest in research in physics, chemistry, and materials science. Impact of the Decline of Education and Training Opportunities in the Field The extent of and reasons for the decrease in basic research at industrial laboratories are discussed later in this chapter. The impact of this decrease on the education and training of young researchers is significant. In the past, many graduates would spend a postdoctoral period at one of the large industrial research laboratories and receive intensive training in DGCM as part of an interdisciplinary team. For the most part, those opportunities are no longer available. Smaller companies that still grow crystals for the industrial or government markets typically do not have the capacity to provide such training. Selected national laboratories have significant efforts in the growth of specific materials, most notably the Ames Laboratory and the Lawrence Livermore National Laboratory (for very specialized materials needed for the National Ignition Facility [NIF]). However, few young people receive training in bulk-crystal growth at those facilities. The lack of federal funding opportunities directed specifically to crystal growth has also taken its toll on efforts to educate and train future growers. As discussed in more detail later in this chapter, programs to investigate new electronic, magnetic, and optical properties of materials or to investigate crystal growth as it relates to challenging processes such as disease, biomineralization, or geochemistry do attract federal support, but support (and thus opportunities for graduate training) for the growth of the materials is much harder to obtain. In the past NASA provided significant support for crystal growth research through its Microgravity Research Program, but the program has been terminated, and many groups that depended on that source have disintegrated. This lack of directed funding has limited the number of research groups in crystal growth. For a number of years, much attention was given in university laboratories to thin-film growth of silicon, germanium, gallium arsenide, and other
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Frontiers in Crystalline Matter: From Discovery to Technology semiconductors important for basic science and industrial applications. Many students were trained and a number of prizes in professional societies were awarded to researchers in this field during the 1980s and 1990s. More recently the synthesis and growth of nanostructures such as quantum dots and quantum wires have become a “hot” field that attracts students and has a strong presence in universities, supported by significant federal funding. Because of shifts in funding, many thin-film research groups have shifted their focus to creating such lateral nanostructures of known compounds while research into creating novel thin-film compounds and exploring their applications lags. While these nanostructures offer exciting possibilities for future technologies, research in thin-film and bulk-crystal growth continues to be of tremendous importance to creating new scientific knowledge as well as advancing existing technologies and enabling the development of new ones. The education provided by university research groups focused solely on nanostructures does not optimally equip young researchers to make contributions in the more established fields of thin-film and bulk-crystal growth. Opportunities for education in bulk-crystal growth are more abundant in Europe and Asia (especially Japan) than in the United States. In regions outside the United States, it appears that the foundational role of DGCM for a wide range of vital technologies and for advances in fundamental science is more widely appreciated, and thus the support for research and education in crystal growth and materials synthesis is more abundant. The Europeans have traditionally had a strong focus on crystallography, with excellent programs in thin-film growth. Recently such programs have undergone significant expansion in Asia. As a measure of the shift in crystal growth expertise from the United States to the rest of the world, one can note that many of the papers submitted to the Journal of Crystal Growth that focus strictly on the growth of materials now come from China. A comparison of the institutions of the authors of papers in that journal in 1992 and 2007 illustrates the point. Of the lead authors published in this journal in the period October–December 1992, 48 percent were at institutions in Europe or the United Kingdom, 23 percent were at Asian institutions, and 28 percent were at institutions in the United States or Canada. During the same months in 2007, the relative percentages of contributing authors had shifted significantly, with 29 percent of the authors at institutions in Europe or the United Kingdom, 58 percent at institutions in Asia, and only 9 percent at institutions in the United States or Canada. The membership of the editorial board and composition of the associate editor listing in the Journal of Crystal Growth show a similar shift, albeit less dramatic. In 1992, approximately 30 percent of the members of the editorial board and associate editors were in Europe or the United Kingdom, 15 percent were in Asia, and 55 percent were in the United States. By 2007 the percentage of members at Asian institutions had increased to 21 percent; the percentage in Europe and the United Kingdom had increased to 26 percent; and the percentage in the United States and
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Frontiers in Crystalline Matter: From Discovery to Technology Canada had dropped to 50 percent (the remaining percentage is associated with a board member or associate editor not from these regions). Expanding the scope of inquiry, a general search of the number of papers published in peer-reviewed journals that involve crystal materials or crystalline materials shows that the United States’ dominant position in the percentage of papers published in this field has dropped considerably over the approximately past two decades. Table 3.1 lists the results of an ISI Web of Science query of papers published in peer-reviewed journals using the search term “crystal/crystalline and materials,” ranked according to nationality of the lead author. In the early 1990s, over one-third of the published papers were from lead U.S. authors. By 2006-2007, that percentage had dropped to less than 20 percent. During that same span of time, authors from the People’s Republic of China went from publishing only a small percentage of papers to publishing the highest percentage. People trained in the United States in crystal growth (especially solution growth) often have difficulty finding jobs. Of the current employment in crystal growth in the United States, the committee estimates that approximately 25 percent are in bulk-crystal growth, with the remainder in epitaxial growth. Jobs in TABLE 3.1 The Top 10 Sources of Papers on Crystal or Crystalline Materials Published in the Years 1990-1992, 1996-1997, and 2006-2007, by Nationality of Lead Author Rank Among Top 10 1990-1992 1996-1997 2006-2007 Country of Lead Authors % of 131 Papers Country of Lead Authors % of 252 Papers Country of Lead Authors % of 748 Papers 1 United States 33.6 United States 22.2 Peoples Republic of China (PRC) 20.4 2 Japan 11.6 Germany 14.8 United States 19.6 3 United Kingdom 11.0 Japan 12.2 Japan 11.6 4 Germany 9.4 United Kingdom 9.0 Germany 11.2 5 France 8.6 France 8.2 France 6.6 6 Italy 4.8 Peoples Republic of China (PRC) 7.8 Russia 5.4 7 USSR 3.6 Russia 7.6 India 5.2 8 Canada 3.4 Spain 4.8 United Kingdom 4.8 9 Peoples Republic of China (PRC) 3.2 Italy 3.8 Italy 4.4 10 India 2.8 India 3.4 Spain 4.2 NOTE: This survey was generated using the search topic “crystal/crystalline and materials” in the ISI Web of Science database, http://apps.isiknowledge.com/.
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Frontiers in Crystalline Matter: From Discovery to Technology nanomaterials are abundant in academia, but universities typically will not hire a bulk-crystal grower (unless the grower can be described as an expert in an adjacent subject area, such as “novel magnetic materials”). National laboratories will occasionally hire such a person when there is a particular need (as at NIF), but this is rare. In the private sector, several small companies produce oxide crystals, but there is little to no U.S.-owned presence in the growth of silicon or compound semiconductor crystals—most of the U.S. manufacturing in this sector is by foreign-owned companies. The varying expectations among relevant departments, combined with the lack of clear programmatic identity in the funding arena, create difficulties in the hiring and promotion of young faculty members. DGCM activities lie at the intersection of physics, chemistry, and materials science. This creates problems for a crystal grower, as the expectations vary considerably for such a person depending on whether his or her primary appointment is in a physics, chemistry, or materials science department, reflecting differences in the prevailing cultures. A member of a physics department would be expected to discover and measure novel properties of crystals grown in their laboratories, with the analysis of the properties of the crystal held in much higher esteem than the synthesis and growth of the crystal. In chemistry departments, significant emphasis would typically be placed on creativity associated with the growth of novel crystals of varying compositions and properties. In materials science departments, the discovery, growth, and characterization of crystals are valued with almost equal weight. The challenges continue even after an individual crystal grower is hired, because tenure still resides in traditional departments, and the scholarly work of young faculty members is typically judged against the traditional standards of research in that department. Although confidentiality factors make gathering detailed data on tenure outcomes extremely difficult, anecdotal evidence indicates that it is not uncommon for granting tenure to a scientist in this field to be made significantly more difficult because members of the tenure committee share but one or another of the views described above. Another barrier to the hiring of young crystal growers is the start-up cost of equipping their laboratories. The committee solicited information from more than a dozen young DGCM scientists who had joined university departments or national laboratories in the past decade. At large research universities, the start-up packages included $330,000 to $870,000 for equipment, with the most expensive item typically costing from $140,000 to $350,000. In some cases the costs would have been even higher if shared equipment (for example, x-ray diffractometers, furnaces, transmission electron microscopes) had not already been available; creating a stand-alone fully equipped laboratory typically costs more than $1 million. The scientists contacted also emphasized that the cost of consumables (such as chemicals, gases, containers, and cryogens) is a significant operating cost. While these start-up costs are feasible for some larger institutions, they are higher than is
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Frontiers in Crystalline Matter: From Discovery to Technology typical for many other areas of physics research, creating a disincentive for universities to invest in this field unless there is a strong expectation of a secure stream of future overhead revenue from the DGCM research program. Findings on Education and Training The Committee for an Assessment of and Outlook for New Materials Synthesis and Crystal Growth presents the following findings related to education and training in DCGM activities: A steady supply of expert DGCM scientists is vital to the continued health of a wide range of technologies and scientific endeavors, yet education and training opportunities for those going into the field have diminished in recent years. The loss of large industrial research laboratories has significantly reduced one of the principal advanced-training opportunities for scientists entering this field. Education and training in the United States for these scientists now occur almost exclusively in graduate programs, with students working in an apprentice mode with one or more professors. However, several factors have limited the increase in these types of programs. First, there exist very few federal funding programs specifically directed to crystal growth, which has limited the number of research groups concentrating in this field. Second, because DGCM activity lies at the intersection of physics, chemistry, and materials science, there is no natural academic home for this research in the discipline-based structure of most universities. Third, the high start-up and operating costs of such research create an additional barrier, especially if questions exist about whether the investment will be supported by a stable source of research funds. As a result, significant constraints exist in providing opportunities for educating and training the next generation of DGCM scientists. ROLE OF INDUSTRY IN CRYSTAL GROWTH Historical Leadership Shifts Since the Mid-1990s Industrial laboratories in the United States and Europe were major drivers of DGCM throughout the 20th century. For example, during the mid-1980s, one of the preeminent industrial research facilities, Bell Laboratories, employed more than 110 full-time staff in DGCM research, at an annual budget in present-day dollars of approximately $30 million.1 Sometimes this role evolved in support of direct—though usually long-term—practicalities: for example, the development of zone refining for silicon crystal growth as a necessity for the semiconductor 1 Private correspondence between committee members and Bell Laboratories personnel—Cherry Murray, Frank DiSalvo, Leonard Feldman, and Walter Brown.
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Frontiers in Crystalline Matter: From Discovery to Technology industry, or of yttrium aluminum garnet (YAG, Y3Al5O12) crystals for laser technology. But it was also true that industrial laboratories were often able to take a visionary stance on new technology. Perhaps nowhere is this clearer than in the development of epitaxial methods for crystal growth, including molecular-beam epitaxy (MBE). MBE and other epitaxial crystal growth methods are now routine and widely used in academia and industry, but they were pioneered in several major industrial laboratories in the 1970s. Figure 3.1 shows the committee’s analysis of a search of the Web of Science using the search term “crystal AND epitax*.” The top-10 cited papers over decadal and then annual periods2 are reported, with the author affiliation for each paper assigned to industry, academia, or national laboratories in the United States, Europe, or Asia. Note that the database coverage of early years is patchy (for example, only titles are searchable), and raw numbers are not comparable from period to period. But the trends are unmistakable, with the early years of the field dominated by the industrial (and also national) laboratories and a substantial shift of leadership occurring in the mid-1990s. Figure 3.2 is a similar analysis of MBE in which the same pattern is clearly discernable. Note that much the same trend is visible for Europe as well. Many reasons can be cited for the initial leadership by the industrial laboratories. First, the development of the needed tools was expensive and required a long-term effort—not easy prerequisites for a single university researcher to meet. Culturally, it seems to have been easier for such research to become established in an industrial environment that did not have concerns about boundaries between technology and branches of fundamental science. Nevertheless, there can be no doubt about impact: the five most-cited papers from a search using the key phrase “molecular beam epitaxy” (35,000 papers in total) describe fundamental emerging technologies from the 1990s that are now prominent. Three of these papers are from industrial laboratories; the other two are from Japan (academia). The five most-cited papers using “quantum well” as a search (39,000 papers in total) include the top two from the MBE list, plus three others. Three of these papers are from industrial laboratories; the other two are from academia (one from Japan and one from the United States). The most-cited papers usually involve technological breakthroughs that had their genesis decades earlier in fundamental research, where again the fundamen- 2 Web of Science searches were conducted by the committee for the following periods: 1970-1980, 1981-1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005. There were not enough papers published annually in the first two decades for good statistics because prior to 1990, the Web of Science indexes only titles. After 1990, the Web of Science indexes both titles and abstracts.
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Frontiers in Crystalline Matter: From Discovery to Technology FIGURE 3.1 Origin of 10 most-cited papers revealed by a citation search of “crystal AND epitax*” on the Web of Science. The papers from Asia are a consolidated number from Asian universities, national laboratories, and industry. The total numbers of papers for the periods shown are 2,543 papers for 1970-1994 and 8,653 papers for 1995-2005. FIGURE 3.2 Origin of 10 most-cited papers revealed by a citation search of “molecular beam epitaxy” on the Web of Science. The papers from Asia are a consolidated number from Asian universities, national laboratories, and industry. The total numbers of papers for the periods shown are 9,955 papers for 1970-1994 and 19,684 papers for 1995-2004. tal papers are widely known3,4 but not always as frequently cited. Interestingly, the keyword searches did not identify two of the most fundamental discoveries in physics—the quantum Hall effects—presumably due to the small size of these fields of study. Nevertheless, it is clear that these discoveries would not have been possible without MBE technology. 3 A.Y. Cho, “Growth of Periodic Structures by Molecular-Beam Method,” Applied Physics Letters, 19, 467 (1971). 4 L. Esaki and R. Tsu, “Superlattice and Negative Differential Conductivity in Semiconductors,” IBM Journal of Research and Development, 14(1), 61 (1970).
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Frontiers in Crystalline Matter: From Discovery to Technology This decline of the involvement in industrial laboratories in basic research is part of a general pattern shown in the more general analysis made by the National Science Board (see Figure 3.3). The decline has been particularly marked in physics. A sharper analysis of this trend is provided by looking at the career trajectories of a number of leading crystal growers, shown in Figure 3.4. By analyzing the careers of these researchers at different stages, it is clear that until the mid-1990s a common career path involved a first position at an industrial laboratory. That option has since largely disappeared. The transfer of major programs out of industrial laboratories into academia over the past decade and a half is also evident—and strikingly, the movement of staff in the reverse direction is almost absent. Lastly, the increasing role of the national laboratories can be discerned. Nevertheless, one notes that the United States has retained a preeminence in the area of crystal growth over four decades, which masks the transfer of activity (and quite often the staff) from industrial and national laboratories to universities. FIGURE 3.3 Articles on basic research in various fields published by scientists in private industry as a percentage of all U.S. basic research articles, 1988 through 2005. SOURCE: Reprinted from National Science Board, Science and Engineering Indicators 2008, Figure 6-27, Arlington, Va. National Science Foundation, 2008. Available at www.nsf.gov/statistics/seind08. Courtesy of the National Science Foundation.
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Frontiers in Crystalline Matter: From Discovery to Technology FIGURE 3.4 Institutional affiliation of selected researchers active in crystal growth, starting with first position after receipt of Ph.D. through 2006. Out of the 29 researchers selected, 12 spent some portion of their career in laboratories operated by industrial companies: Bell Laboratories (7), DuPont Laboratories (2), International Business Machines Laboratories (2) and LTV Research Center (1). Out of 29 researchers, 16 spent some portion of their career in a government laboratory (some spent time at more than one laboratory): Los Alamos National Laboratory (5); Ames Laboratory (3); Oak Ridge National Laboratory (3); Argonne National Laboratory (2); Brookhaven National Laboratory (2); Sandia National Laboratories (1); National Institute of Standards and Technology (1); National High Magnetic Field Laboratory (1); CRISMAT, France (1); and ISTEC, Japan (1). Findings on the Role of Industry in Crystal Growth The Committee for an Assessment of and Outlook for New Materials Synthesis and Crystal Growth presents the following findings related to the role of industry in DCGM activities: The conclusions here are stark. The industrial laboratories historically provided leadership in both fundamental and applied materials research until the 1990s, and while the United States has kept preeminence in many areas, this position rides substantially on fundamental investment that was made more than two decades ago and which has not been maintained. Particular concern arises over the training and support of young researchers. While the data are slim, the paucity of career movements between academia, industry, and the national laboratories over the past decade is of concern.
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Frontiers in Crystalline Matter: From Discovery to Technology INNOVATION AND DISCOVERY The field of the discovery and growth of crystalline materials is invigorated periodically by discoveries of new materials, or by discoveries of new physical properties of existing materials. In a discipline such as condensed-matter materials, major discoveries often emerge unexpectedly in areas of research that might have seemed dormant or previously unexplored. Famous examples of this include the discovery of high-temperature superconductivity in the copper oxides and of exotic superconductivity in heavy-fermion compounds, the (re)discovery of enormous magnetoresistive properties of some rare-earth manganites, the emergence of carbon nanotechnologies (fullerenes, nanotubes, graphene), and the development of polymeric and organic compounds as light-emitting diodes, sensors, detectors, and photovoltaics. In these fields, single discoveries can lead to a profound reorientation of the discipline and the genesis of important technologies. It is clear that the future strategy of condensed-matter materials must include a vigorous component focused on such groundbreaking research. The importance of materials discovery science is quantified in Figure 3.5, in which for three materials classes (the colossal magnetoresistance [CMR] manganites, the anomalous metallic ruthenates, and the heavy-fermion superconductor UBe13) the committee reviewed citations to a single “discovery” paper (blue) and compared that to the total papers published on the topic. Note that a single paper can have a preponderant as well as a catalyzing effect. For example, as shown in Figure 3.5(c), a key paper has more citations than the total number of papers published subsequently referring to the same material (UBe13)—since the discovery (in this case of unconventional superconductivity) impacts a much broader field of science. How good is the United States at engendering materials discovery science? The record is mixed and variable by subfield. To explore this topic in more detail, the committee looked at results in the subfields of superconductivity, magnetic materials, and intermetallic compounds. These subfields were selected because they are highly active areas of research and because advances typically made in these subfields are directly related to advances in crystal discovery and growth. Superconducting Materials The data in the top panel of Figure 3.6 show that for superconducting materials, the United States was a clear leader in measurement science in the mid-1990s, and the U.S. contribution to synthesis of samples, shown in the bottom panel of Figure 3.6, was comparable to that of Europe and Japan. Over the past decade, however, contributions from measurement science in the United States have waned, while the Japanese effort has increased and is now comparable to that of the United States. The impact of synthesis efforts in Japan has clearly exceeded that of the
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Frontiers in Crystalline Matter: From Discovery to Technology TABLE 3.2 Comparison of the Productivity of Materials Grower Group and Highly Cited Comparison Group for 1996-2006 Materials Grower Group (per researcher) Highly Cited Comparison Group (per researcher) Frequent coauthors 142.7 79.2 Total coauthors 836.2 454.7 Total papers 597.1 351.1 h index 70.9 62.9 Years of research experience 33.3 43.4 NOTE: Publication data were collected for 1996-2006. “Frequent coauthors” are individuals who have coauthored papers with a specific materials grower five or more times. “Total coauthors” is the total number of coauthors for the publication years for a member of one of the groups. All values are averages for the groups. with the researcher on the list during the search years of 1996 to 2006. Since the comparison group has over 10 years more of average research experience, it is advantageous to compare rates of productivity by dividing by the number of years of experience. This comparison, shown in Figure 3.10, reveals several interesting features. First, the growers are remarkably prolific researchers, with publication rates and numbers of unique and frequent coauthors more than double that of the (also extremely productive) comparison group. This high productivity allows a relatively limited number of growers and synthesizers to have a substantial scientific impact: Their efforts are highly leveraged by the efforts of their many collaborators. Second, the materials grower group sustains a very high publication rate in absolute numbers: An average of nearly 18 publications per year per grower represents an astonishingly high demand (and workload) for this group of researchers. U.S. FUNDING FOR DISCOVERY AND GROWTH OF CRYSTALLINE MATERIALS RESEARCH Historically, support for basic research in DGCM was distributed from across many federal agencies and programs and was also supported by industry. There have not been specific federal programs that fund basic research in the discovery and growth of crystalline materials, and thus it is hard to quantify the total investment or trends in investment in DGCM activities. However, in an effort to quantify the present level of support and to determine the appropriate size of the U.S. effort in DGCM, 28 experts around the country in the discovery and growth of crystalline materials were surveyed by the committee. These experts were asked to provide information on the demand for synthesized materials and on their research support. The results of this inquiry are discussed below, followed by an overview analysis of the state of DGCM support by major federal agencies.
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Frontiers in Crystalline Matter: From Discovery to Technology FIGURE 3.10 Comparison of the productivity of a group of 10 high-impact crystalline materials growers (selected by the committee) and a group of 10 solid-state experimental physicists (from ISI’s Highly Cited list), normalized by the number of years of research experience. “Frequent coauthors” are individuals who have coauthored papers with a specific materials grower five or more times. “Total coauthors” is the total number of coauthors for the publication years for a member of one of the groups. All values shown are averages for the group. Publication data were collected for 1996 to 2006. Survey of Experts in the Discovery and Growth of Crystalline Materials To help estimate the need in the science community for high-quality crystalline samples, the survey conducted by the committee asked 28 experts in DGCM about the number of materials requests that these experts receive in a given year. By considering the results of the survey and engaging in follow-up discussions with experts, the committee determined that there is significant underfunding of the field of materials synthesis and crystal growth. Underfunding for the field is exacerbated by the small number of experts in DGCM and by the tendency of that small number to focus on materials of personal interest and of relevance to their own established collaborations, as described in the two points below. The questions in the survey were constructed for “growers,” not for “measurers.” The classification of the scientists into these two groups by the
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Frontiers in Crystalline Matter: From Discovery to Technology phrasing of the questions was considered to be inaccurate and offensive to those polled. Each grower is an outstanding scientist who understands the importance of control of novel materials for obtaining basic scientific information on intrinsic properties. None of them is simply a “supplier” of samples. According to the survey results, in many cases the growers and measurers are part of the same group, and in some cases the same person fills both roles. In all other cases, the growers and measurers work in a highly collaborative mode. This makes for better science, but it also limits external interactions: The grower plays an active part in every collaboration (so time is a limit) and only collaborates on measurements with materials of interest to the grower. Therefore, measurers with interests that do not overlap with those of particular growers may not be successful in procuring materials for their experiments. According to the survey results, the ability to obtain crystalline samples for experiments depends on the researcher’s status and familiarity with the expert grower. Requests for samples, even from respected researchers at research universities, often require multiple attempts. Furthermore, researchers from less prestigious institutions often do not even attempt to make materials requests, knowing that the requests will not be fulfilled. Therefore, the true number of samples that are needed and of laboratories that need materials must be larger than those reflected in the collected data. As stated above, many requests for materials are made by measurers, but it is impossible for each request to be fulfilled. Over the past few years, on average each grower rejected requests from approximately 35 to 40 researchers per year and approximately 100 materials requests per year from those researchers. Coupled with the two points above, it is evident that hundreds of researchers are unable to get materials from growers at all, and on the order of thousands of materials requests remain unfulfilled. The 28 experts surveyed were also asked about their present support and the level of support that they would need to fulfill all sample requests received. Those polled could not separate funding for the “growth” from the “materials research and measurement” part of their research. A significant fraction of their research funding supports discovery, characterization, and analysis for greater understanding of the novel materials, and the fraction of funding used to grow materials for outside collaboration is not clear. There was universal agreement among the 28 experts, however, that a factor-of-two increase in support would be needed to fulfill their sample requests. The increase is required both in supplies and in personnel; as stated clearly by one scientist: “My group would have a larger number of requests for samples if we could make faster progress on materials growth and characteriza-
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Frontiers in Crystalline Matter: From Discovery to Technology tion. We would be able to make faster and better progress and accommodate the larger number of requests for samples with more adequate funding.”7 When they were asked what is needed for the United States to be a world leader in DGCM research, the most common answer given by this group of experts was the need for an increase in current levels of DGCM funding support by a factor of three to four. The committee finds this factor to be consistent with its observations, given that the factor-of-two increase for these experts to meet current demand does not take into account the needs of existing scientists who would like crystals but are not well connected and so do not ask for new crystalline materials, nor does it reflect the fact that there are other researchers who, because of a lack of access to state-of-the-art crystalline materials, forgo the opportunity to work in this field. Such additional support is needed not only for DGCM research and materials growth for collaborative experiments but also for training students in this area. At present, there are five national laboratories funded by the Department of Energy—Ames Laboratory, Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, and Oak Ridge National Laboratory—that house significant materials growth efforts. These national laboratories interact strongly with a few key universities. One scientist, who called this the “hub and spoke” model, believed that it represents a reasonable way to support this field but that overall support is too low, both internally for the national laboratories and with respect to their ability to interact with the universities. The committee believes that increasing the DGCM support in national laboratory “hubs” would strengthen existing collaborations and also allow an increase in the number of “spokes” to include universities that historically do not have strong connections with national laboratories. However, the committee believes that a single approach of strengthening support for DGCM research at national laboratories will not be sufficient to advance science and technological industries dependent on discoveries in new materials and crystal growth. The spokes in such a model are equally important, and direct, concomitant support for research programs at universities would be essential. Support for Discovery and Growth of Crystalline Materials Activities Support for research in the discovery and growth of crystalline materials has historically come from federal programs and from industry. Some of the federal programs no longer support this research, and industry support has waned in recent years. This subsection describes the changing landscape of support for DGCM research. 7 Survey response.
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Frontiers in Crystalline Matter: From Discovery to Technology Industry The precipitous decline in DGCM research in industrial laboratories is described earlier in this chapter. While many industrial researchers have shifted to academia, the scale of the work has significantly changed, resulting in a net loss of funding for the field. The industrial laboratories were also a significant training ground for new scientists interested in the discovery and growth of crystalline materials. Declining research in DGCM activities thus also negatively impacts opportunities for the education of young researchers. National Aeronautics and Space Administration For more than 30 years, from the early 1970s until it was phased out in the early 2000s, NASA’s Physical Sciences Division funded research into physical processes that are significantly affected by gravity. Materials science was one of the five broad areas included in the Microgravity Research Program. Crystal growth and defect control constituted one of the research themes within the materials science research program. During the mid-1990s, the Microgravity Research Program had a budget of approximately $100 million and funded approximately 400 projects. On average, 80 ground-based materials science projects were sponsored each year. A report published in 2003 by the National Research Council, Assessment of Directions in Microgravity and Physical Sciences Research at NASA, noted that the impact of NASA’s materials research program was especially significant in the area of solidification and crystal growth.8 The phasing out of this program in the early 2000s represents a significant loss of support for DGCM. National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) also had a significant effort in the growth of bulk-scale single crystals and the modeling of growth processes in the 1990s. This emphasis has waned, and current research on single crystals at NIST has focused on the characterization of materials rather than the growth of new crystalline materials. Current research at NIST in DGCM activities is carried out in several cross-collaborative efforts, which makes separating out the staffing and budgeting for such activities impracticable. 8 National Research Council, Assessment of Directions in Microgravity and Physical Sciences Research at NASA, Washington, D.C.: The National Academies Press (2003).
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Frontiers in Crystalline Matter: From Discovery to Technology Department of Defense Research in the discovery and growth of crystalline materials at the Department of Defense (DOD) is included in the basic research budget (6.1). Figure 3.11 shows that 6.1 funding at DOD has been approximately flat for the past 15 years. In addition, research supported by DOD must focus on mission applications. Although the amount of DOD’s 6.1 spending for DGCM-related activities is not available, the combination of these factors suggests that support for DGCM activities at DOD agencies would likely be narrow in scope and approximately constant for the past 15 years. Department of Energy and National Science Foundation In the Department of Energy, Basic Energy Sciences supports DGCM research. At the National Science Foundation, DGCM research is supported by the Division of Materials Research in the Directorate for Mathematical and Physical Sciences. These two federal agencies support the majority of basic research in DGCM conducted at U.S. universities. Within each agency, the support is derived from many programs such as those for condensed-matter physics and solid-state and materials chemistry. For this reason, it is difficult to determine trends in DGCM support—essentially every grant awarded in these programs would have to be reviewed to determine whether DGCM research was involved. However, the overall funding for these programs has been approximately flat for the past decade.9 Thus, it is reasonable to estimate that DGCM research activities have also been held constant in this time frame. Findings on Support for Discovery and Growth of Crystalline Materials Activities The Committee for an Assessment of and Outlook for New Materials Synthesis and Crystal Growth presents the following findings related to U.S. funding for basic research in the field of DGCM: Traditionally, industrial research laboratories conducted much of the basic research in the DGCM field in the United States. The decline in industrial efforts in this area leaves a large gap in overall support for DGCM activities in the United States. According to the committee’s survey of and discussions with DGCM experts, federal funding for the DGCM field has not made up for this loss—hundreds of scientists go wanting for thousands of samples—and the United States will only be able to meet the demand of U.S. researchers for 9 National Research Council, Condensed-Matter and Materials Physics: The Science of the World Around Us, Washington, D.C.: The National Academies Press, 2007.
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Frontiers in Crystalline Matter: From Discovery to Technology FIGURE 3.11 Support for basic research (6.1) at the Department of Defense has been approximately constant for the past 15 years. SOURCE: American Association for the Advancement of Science (AAAS), “Trends in DOD ‘S&T’,” FY 1994-2009 chart, February 2008, available at http://www.aaas.org/spp/rd/trdodst09pa.pdf. Data based on AAAS analyses of research and development (R&D) in annual AAAS R&D reports. The FY 2009 figures are the most recent AAAS estimates of the FY 2009 request. Medical research appropriated outside RDT&E [research, development, testing, and evaluation] funding; appropriated in “6.2” accounts before 1999. crystals by doubling the amount of federal support for DGCM efforts. In order for the United States to achieve the rank of world leader in DGCM research, the experts surveyed by the committee believe that funding would need to increase by a factor of three to four times current funding levels. Because there are no current federal programs whose focus is funding basic research in the discovery and growth of crystalline materials, it is hard to quantify current total investment or historic trends in investment in DGCM activities. However, the few programs that were directed to DGCM efforts in the past have been phased out, while those programs indirectly funding DGCM efforts, for the most part, have seen their budgets remain flat. INTERNATIONAL ACTIVITIES The discovery and growth of crystalline materials have been an active area of research in Europe and Asia, especially in Japan, China, and Korea. As discussed
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Frontiers in Crystalline Matter: From Discovery to Technology below, three factors appear to be important in the promotion of DGCM activities in these countries. Centers for the Discovery and Growth of Crystalline Materials Research DGCM centers with concentrated human resources and significant budgets are undertaking initiatives to promote DGCM activities in Europe and Asia. These efforts appear to be quite effective when the research target is well defined and closely linked to industry. In Germany, for example, the Institute for Crystal Growth (IKZ) in Berlin and the Department of Crystal Growth in the Fraunhofer Institute for Integrated Systems in Erlangen employ staffs of 93 and 35 people, respectively. IKZ in particular has been very active in the growth of semiconductor crystals (such as silicon, gallium arsenide, gallium nitride, and zinc oxide) and optical crystals (such as fluorite), as well as in the development of growth and characterization techniques. A range of research expertise and crystal growth expertise is supported at these centers—computational modeling, analytical services, and technique development—to create an overall capability that does not exist in the United States. These two German centers operate on a blend of funding from both industry and government sources. According to IKZ’s latest annual report, its staff of 93—40 scientists, 42 technicians, 9 Ph.D. students, and 2 diploma students—is supported by an annual budget of 9.0 million euros (11.5 million U.S. dollars)—7.14 million euros (9.1 million U.S. dollars) from government funding and 1.87 million euros (2.4 million U.S. dollars) from projects and industrial grants.10 While separate figures were not available for Fraunhofer’s Department of Crystal Growth, the overall annual funding for Fraunhofer’s staff of 140 people was 11.0 million euros (14 million U.S. dollars), with approximately 43 percent provided by industry, 18 percent provided by the German government, and the balance of funding from international sources, with the large majority from the European Union.11 Other examples of focused DGCM centers can be found in China. China has been playing a leading role in the growth of optical crystals, including borates such as lithium borate (LBO) and barium borate (BBO), and consequently dominates the market for these materials.12 The Chinese Academy of Sciences has three crystal growth centers (in Fujian, Beijing, and Shanghai), each with a large number of 10 IKZ Annual Report 2007/2008, p. 7. See http://www.ikz-berlin.de/publications_folder/report_folder/jbm0807/jb_08_02.pdf. Last accessed March 11, 2009. 11 Fraunhofer IISB Annual Report 2007, p. 28. See http://www.iisb.fraunhofer.de/de/jber/Annual_Report_IISB_2007.pdf. Last accessed March 11, 2009. 12 Recent articles describe the very real and negative consequences for those researchers not having access to such crystals. See David Cyronoski, “China’s Crystal Cache,” Nature, 457, 953 (February 19, 2009).
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Frontiers in Crystalline Matter: From Discovery to Technology scientists and technicians focused specifically on the growth of optical crystals. The success of China in optical crystal growth has been enabled by the presence of such focused and concentrated DGCM research efforts. Research Support In addition to the large centers for DGCM research, European and Asian countries have established programs that recognize the importance of and therefore provide funding for DGCM activities for individual researchers and smaller groups. In Japan, for example, DGCM activities are well supported as a part of group budgets. In addition to providing individual research grants (equivalent to National Science Foundation funding in the United States), the Japanese Ministry of Education, Sports, Science and Culture funds collaborative research activities as “Scientific Research of Priority Areas.” At the time of this writing, five such programs were running in materials physics. Each program consists of about 20 principal investigators with a typical budget of a few million U.S. dollars (USD) per year. Within the program, crystal growth can be a priority in the budget. The Japan Science and Technology Cooperation has a program called Core Research for Evolutional Science and Technology, which is a strategic budget in the government that supports a few principal investigators with about 1 million USD per year. These budget sources, as well as the fact that students and staff are financially supported at the department level rather than at the principal-investigator or project level, allow considerable support and flexibility for DGCM activities in Japan. In addition to the group budget systems mentioned above, a program in Japan providing single principal investigators with exceptionally-large-scale budgets (15 million to 20 million USD for 5 years) is noteworthy. The Exploratory Research for Advanced Technology (ERATO) program is operated by the Japan Science and Technology Agency and funds 5 to 10 projects on materials, running in parallel. Very strong DGCM activities often have been conducted as part of the ERATO program, and this funding played an important role in the recent Japanese discovery of iron pnictide superconductors (see Box 3.1). Because of the programs described above and similar programs, in the past decade Japan has become the leader in DGCM for superconductors, strongly correlated oxides, organics, and quantum magnets. In fact, large single crystals of these systems grown in Japan are now often provided to researchers in the United States for subsequent study. Many new superconductors, including MgB2, have been discovered in Japan recently and have stimulated research in the U.S. materials physics community. The group funding approach also can be found in Europe, both at the individual country and at the European Union level. For example, the United Kingdom funds a program entitled “Portfolio Partnership” under the Engineering and Physical
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Frontiers in Crystalline Matter: From Discovery to Technology Sciences Research Council. This program supports a group working on exotic quantum materials, which grows hundred-gram single crystals of high-temperature superconducting cuprate samples for neutron-scattering studies. Similar programs supporting DGCM research can be found in Germany, France, and Switzerland. Canada also supports programs for DGCM research, under the Canadian Institute for Advanced Research,13 which funds research growing ultrahigh-purity single crystals of cuprates. Small Cultural Gap Separating Disciplines The third factor contributing to the success of DGCM activities in Europe and Asia is the smaller cultural gap, compared to that in the United States, separating research groups and disciplines and thus facilitating collaboration. For example, the cultural gap between physics and crystal growth is relatively minor in Japan, partly because students are encouraged to train for DGCM research. Educational opportunities presented in research groups merge materials and physics at the graduate level. Graduate students also have an opportunity to learn both crystalline matter synthesis and measurements early in their careers. This leads to the virtuous cycle of generating future principal investigators who have strong expertise and interest in both materials and physics. It is also common in Japan for physicists working on specific crystals to grow their own crystals and then to make them readily available to others: a kind of “borderless” approach seen in the fields of oxides, heavy fermions, and organic conductors. Indeed, it is often the case that crystals supplied from Japan to the United States are grown by physicists actively working on specific probes rather than by professional growers. The size of the groups in Japan also facilitates developing expertise in growing crystals. Often more researchers work under one principal investigator in Japan than in the United States. At the top universities, 1 or 2 junior faculty members (between a postdoctoral associate and an assistant professor), a few postdoctoral associates, and 5 to 10 students work with a professor. This large group size enables a single research group to work on both materials synthesis and measurements. Findings on International Activities The Committee for an Assessment of and Outlook for New Materials Synthesis and Crystal Growth presents the following findings related to international activities in the field of DGCM: Efforts in Europe and Asia to develop their DGCM activities focus on three factors: (1) the development and sustained funding of 13 For more information, see http://www2.cifar.ca/. Last accessed April 1, 2008.
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Frontiers in Crystalline Matter: From Discovery to Technology large centers, which are particularly effective when the research target is well defined; (2) the establishment of programs funding smaller groups and individual researchers that emphasize the importance of the discovery and growth of crystalline materials; and (3) cultural aspects of the education, training, and engagement in crystal growing and research, especially in Japan. These factors together have accounted for a large part of the success in DGCM research in these countries.