An Assessment of the National Institute of Standards and Technology Material Measurement Laboratory: Fiscal Year 2014 (2015)

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Materials Measurement Science Division

The Materials Measurement Science Division (MMSD) was created by the merger of the former Ceramics Division of the Materials Science and Engineering Laboratory, the Surface and Microanalysis Science Division of the former Chemical Science and Technology Laboratory, and the Securities Technology Group, formerly part of the Office of Law Enforcement Standards. This is a large division, with more than 160 employees spread over eight buildings.

The MMSD provides the measurement science, measurement standards, and measurement technology required to enable characterization of materials in support of the nation’s needs. The work emphasizes the determination of the composition, structure, and properties of materials. The technical work is divided into eight groups: Microscopy and Microanalysis Research Group, Nano Materials Research Group, Materials for Energy and Sustainable Development Group, Surface and Trace Chemical Analysis Group, Synchrotron Science Group, Materials Structure and Data Group, Nanomechanical Properties Group, and Security Technologies Group.

The eight groups share a common umbrella of characterization of the structure, properties, and composition of materials. The research topics range broadly from fibers used in soft body armor systems, to crystal structure determination of materials, to surfaces and nanoscale systems. The research topics are roughly organized by four main technical thrust areas: advanced manufacturing; advanced materials; safety, security, and forensics; and sustainability and energy. However, at this early stage of the MMSD the scientists seem more closely aligned with their particular group rather than with the research thrust areas.

ASSESSMENT OF TECHNICAL PROGRAMS

Accomplishments

The Microscopy and Microanalysis Research Group performs research in, and development of, microscopy and microbeam analysis techniques for the compositional, morphological, and crystallographic characterization of matter down to atomic spatial scales. The instruments use excitation by beams of electrons, ions, and photons. The group develops improved methods of quantification as well as documentary standards, SRMs, and SRD. These techniques are used effectively to address problems in materials science and chemical science, semiconductors, optoelectronics, environmental and biological sciences, and processes.

The Nano Materials Research Group develops standards and innovative metrology to advance nanomaterial research and applications for the benefit of U.S. commerce. Its goals are to determine the physical and chemical properties of a wide variety of nanoscale organic, inorganic, biomolecular, and hybrid systems, resulting in standards, methods, reference materials, and measurement data to advance a wide range of technologies and stimulate innovation.

This technical thrust is focused on advanced materials on the nanometer scale, addressing topics such as developing actinide microspheres for validating spectroscopes, adsorption of monolayers, crosscutting work on the structure and properties of nanowires, advanced manufacturing, and device

fabrication. All these topics are in response to the needs of industry and other federal agencies.

The Materials for Energy and Sustainable Development Group has performed work on a portfolio of fabrication and characterization techniques, with emphasis on energy harvesting, energy efficiency, and CO₂ capture. Two closely related projects involve the deposition of phase-spread heterogeneous thin films. This thin film technique is applied to Seebeck coefficient certifiable standards and the high-throughput combinatorial screening of multicomponent systems. This supports sustainable development because it holds promise for converting industrial waste heat to electrical energy. The same high-throughput screening technology was applied to passive smart window coatings that exhibit temperature-dependent infrared reflectivity. A closely related metrology advance is the development of an nJ-sensitivity nanocalorimeter, which can be used to study phase changes in thin films. This group also collaborates with the Department of Energy’s (DOE’s) National Energy Technology Laboratory in the characterization of metal organic framework structures that have been proposed for use as CO₂ scrubbers. These projects are very relevant and timely, and they exploit the unique analytical and metrological resources of the MMSD. The combinatorial high-throughput studies are also highly relevant to the Materials Genome Initiative. This group is making efficient use of high-quality instrumentation to address selected problems ranging from specific research on high Seebeck thermoelectrics to globally significant carbon capture and mitigations. This field is highly competitive and fast moving. Care is needed in selecting problems where MMSD strengths can be leveraged.

The Surface and Trace Chemical Analysis Group conducts research on the chemical and structural properties of matter by applying various ion- and photon-based microscopies to provide spatially resolved elemental, isotopic, and molecular information. The group studies the fundamental aspects of the excitation process and addresses quantification, standards development, instrument improvements, and data analysis challenges associated with these analytical methods; the group applies the methods to autoradiography and nuclear track methods, size calibration of particles, trace detection of explosive and narcotic particles, and advanced flow visualization.

The Synchrotron Science Group develops and disseminates science and technology pertaining to the measurement of structure, including chemical and electronic, of advanced materials by synchrotron methods. This is a long-standing and extremely productive collaboration between NIST and DOE. The primary focus is on spectroscopy and microspectroscopy techniques that span the soft to hard x-ray regimes. There is a significant investment from NIST to build, maintain, and support the synchrotron measurement capabilities at the National Synchrotron Light Source (NSLS) I/II; it also places staff and associates at the Brookhaven National Laboratory.

The Materials Structure and Data Group is concerned with the measurement of atomic structure using neutron and x-ray techniques and with electron microscopy. There is a complementary first-principles modeling effort. The group is also concerned with the essential, challenging job of developing uniform electronic means for communicating and navigating such complex data sets as phase diagrams and crystallographic structure determinations, which formerly were archived graphically in journals and books, and which use a variety of different arcane naming conventions. Current structure and imaging work is complementary to other MMSD efforts, including the imaging of thin films for photovoltaics. The curation and dissemination of structure and phase data are essential to the Materials Genome Initiative and to compliance with the Digital Accountability and Transparency Act (DATA). The materials and structure database has also yielded fruit by permitting automatic checking of historical data for internal consistency. This group maintains SRD on crystallography and structure (SRD 3, 83, 84) and phase equilibrium (SRD 31) and provides associated SRMs.

The Nanomechanical Properties Group develops measurement techniques for the mechanical response of submillimeter material. Recent successes include high-quality and high-throughput stress-strain relations on Θ-shaped machined samples (where samples are typically hundreds of µm for ceramics and 50 µm for metals) and the development and calibration of atomic force microscopy (AFM) flexural and torsional cantilevers, including cantilever SRMs. The stress-strain relations are approaching the ability to measure the response of individual grains. Another noteworthy achievement is the measurement of curvature of thin films using a specially modified x-ray lattice comparator. This work is unique and of

the highest caliber. With NIST’s historical contribution to fracture and failure, this work is poised to give the Materials Genome Initiative a solid database of reliable mechanical response that is particularly well-suited to understanding and validating multiscale models. The group is further developing a collocated nanomechanics clean-room facility that could be a division-wide resource and have the potential for nucleating cross-division collaborations. The Nanomechanical Properties Group is developing an impressive suite of techniques to measure mechanical, adhesion, and strain properties at multiple length scales. The prospect of achieving single-grain response and of extending these experiments to other temperature and mean pressure states is exciting and could revolutionize understanding of the mechanical response of all condensed matter.

The Security Technologies Group focuses on measurement science as it applies to body armor, the detection of hidden weapons using millimeter-wave imaging, and more exotic technologies such as those for the detection of individuals buried in rubble or obscured by walls. The work of this group has a strong focus on Department of Justice needs and also benefits from interaction with the Army Research Laboratory (ARL). The body armor study combines ballistic testing with measurement of aging (hydrolysis) effects of the relevant polymers, fabrics, and composites. The ballistic testing uses a dedicated indoor firing range with a configurable, handgun-scale, remotely operated breech. A novel, very-high-resolution laser velocimeter determines projectile velocity. The quality of work is very high, benefiting from the great variety of expertise at NIST, ranging from textiles to optics. However, the testing facility itself is not unique, and experiments of equal caliber might be conducted with ARL or other research associates.

Opportunities and Challenges

The Nano Materials Research Group and the Materials for Energy and Sustainable Development Group are doing high-quality research and yet are relatively small players in very big fields that are seeing major investments around the world; one implication of this situation is that the groups will need to specify the niches in which they are likely to make the greatest contributions and to adjust their niche as developments warrant. The Security Technologies Group appears to be without clear cross-cutting roles. While this group could benefit from the leading instrumentation available in the other groups within the MMSD, these partnerships are in the very early stages of development, and so there is much room for growth.

The Surface and Trace Chemical Analysis Group, which works closely with the Security Technologies Group, is at the forefront of ion- and photon-based imaging and spectroscopy, is extraordinarily well equipped across the board, and is recognized as being at the forefront of such techniques. One exception to this statement is the 3-D atom probe, which is an instrument to which the MMSD has come rather late in the game. Nevertheless, the 3-D atom probe is a field in which quantitative understanding of data and standards is needed, so there is opportunity for significant impact.

The Synchrotron Science Group has one of the leading materials-characterizing facilities in the world and runs an effective user facility, considering performance metrics that include number of papers published (90-100 every year from facility users), number of high-profile papers, and number of users (more than 100 industry and academic researchers). The Synchrotron Science Group is performing at the highest level. Its development of soft x-ray analysis and imaging is extraordinary. It has been developing unique synchrotron techniques. This research effort comes at a time of transition—the closing of the National Synchrotron Light Source (NSLS) I and the commissioning of NSLS II. During this transition, 16 spectroscopy beamlines at NSLS I will be reduced to 3 in NSLS II; the MMSD team will be the lead for 2 of these. This transition will cement the MMSD Synchrotron Science Group’s position at the forefront of x-ray characterization of materials, which will be critical to the success of NSLS II.

When the NSLS II is commissioned later this year, its new beamlines—spectroscopy soft and tender (SST)1, SST2, and the beamline for master measurements (BMM)—will have a number of unique capabilities. The three beamlines will be designed for high throughput to optimize new materials

discovery; they are well positioned to contribute to the Materials Genome Initiative. The combination of workhorse techniques for characterizing materials with new developments in spectroscopy and spectromicroscopy techniques is impressive. The soft x-ray emission and near-edge x-ray absorption fine structure (NEXAFS) technique is very powerful and shows the power of leveraging the capabilities of NIST at Gaithersburg, Maryland, and Boulder, Colorado, in order to develop and implement the microcalorimeter array for detection. The hard x-ray photoelectron spectroscopy (HAXPES) full-field magnetic projection microscope is also an exciting advance. The transition from NSLS I to NSLS II required a recent investment of $8 million. The current institutional services (IS) tax imposed on all expenditures that started in fiscal year 2013 constitutes a particular burden for synchrotron activities. It would be a shame if this highly collaborative and important program were damaged due to recent changes in overhead policy.

Overall Assessment of Technical Programs

The dispersal of MMSD scientists across eight buildings in Gaithersburg and a separate National Laboratory makes it challenging to grow a coherent division. Cross-cutting thrust areas, such as the Materials Genome Initiative, are of secondary interest to most of the scientists, but much of the work in all the groups fits well into the MML thrust areas. It is too early to see whether the decades of preexisting collaborations are being enhanced by the new organizational structure. Certainly there are many opportunities to build new collaborative efforts. There are, however, concerns among the staff about the loss of opportunities for collaborations with entities outside NIST because of increasing budgetary, administrative, and legal constraints. Overall, the technical programs in the MMSD vary from world-leading centers to groups in need of improvement and better integration to form a more coherent division.

PORTFOLIO OF SCIENTIFIC EXPERTISE

MMSD staff are scientific leaders in the areas of x-ray methods, electron microscopy, and surface analysis. The Brookhaven NSLS group is noteworthy for its leadership and innovation in synchrotron spectroscopy and imaging methods.

Expertise in atomic structure and thermodynamics supports the development of databases on material structure and phase diagrams and x-ray diffraction and spectroscopy, which directly support the division’s core mission of supporting industry through the development and dissemination of standards.

The development of new micro-indentor instrumentation exemplifies the division’s historical expertise in building state-of-the-art instrumentation. The microscale stress–strain measurement capability is innovative and extends the division’s expertise in strength and failure in materials. The work on nanoparticle separation and high-throughput analysis is very good, and the MMSD has established unique expertise in this area. However, it is not evident that the MMSD nanoparticle expertise is equally strong in all areas of this broad and rapidly expanding field. The measurement of thin-film structure and chemical characterization and the measurement of thin-film thermodynamics are outstanding. The more applied research is on thin films, and related applied research in the energy area is good and on a par with that in academia. The junior staff are excellent and reflect the success of the National Research Council postdoctoral program to attract energetic researchers to the division. They appear very happy with the research environment and are well mentored by the senior staff, but they have expressed concern about the increasing demands of paperwork and restrictions on travel.

Because of the dearth of technicians, Ph.D. scientists do routine tasks like computer system maintenance, which is a poor use of their skills and resources. There is a strong need for technician support, particularly for information technology support, in view of the mandate to make public all data. The current computer infrastructure is not equal to the task.

In the Microscopy and Microanalysis Research Group and in the Surface and Trace Chemical

Analysis Group there is an outstanding blend of senior and younger scientists and engineers who are excited about the science they perform and the instruments they develop and who are creating innovative instrumentation and needed SRMs, software, and comprehensive reports.

The Synchrotron Science Group also has an outstanding blend of senior and junior scientists. The group leader has more than 20 years of experience with synchrotron techniques and interfacing with industry. The group delivers a great deal of output given its limited size.

The Materials and Structure Data Group might benefit from increased collaboration with the Brookhaven Synchrotron Science Group.

The Security Technologies Group has unique expertise in millimeter-wave detection and imaging. However, the body armor research does not connect well with the core strengths of the MMSD, which emphasize atomic scale characterization and thermodynamics.

ADEQUACY OF FACILITIES, EQUIPMENT, AND HUMAN RESOURCES

Overall, the ratio of equipment capital to human capital is high, consistent with the MMSD mission to pursue state-of-the-art metrology, microscopy, and spectroscopy. Within the division, there are a number of capabilities to measure and characterize materials that are unique, either to NIST or to the broader international research community.

The test bed for trace explosives supports the deployment of screening technologies to NIST gates and to the training of law enforcement officers. State-of-the-art microscopy and microanalysis instrument suites cover elemental, compositional, and phase characterization of particle and thin film sample systems that are relevant to national security and support collaborative research efforts within the division and across NIST. Unique materials formulation and fabrication facilities address the needs of outside agency customers. Developed capabilities also include a novel passive millimeter-wave imager and test bed; a suite of gravimetric materials deposition printers for standards production; a suite of custom-designed nano-indenters; and unique synchrotron end stations and spectro-microscopes. A NIST-developed measurement system combines a modified electrospray-differential mobility analyzer coupled to an inductively coupled plasma mass spectrometer; this unique capability allows selection of particles of a specific size, with sub-nanometer resolution, counts the particles and analyzes them for core and surface elemental composition. The partnership with Brookhaven is of the highest quality and deserves continued support. The MMSD is also pushing the limits of techniques such as 3-D atom probes, nano-indentation, secondary-ion mass spectrometry (SIMS), and electron microscopy and microanalysis.

Despite funding issues, the Microscopy and Microanalysis Research Group has been highly successful in building a set of scientific instrumentation that is within the top 10 in the world, including top-of-the-line commercial instruments and unique inventions, which are used to address hitherto-unanswerable materials questions. The group is well staffed, well led, well equipped, doing outstanding research, providing globally recognized SRMs, and addressing the industry and national security needs that are brought to it.

In the Nano Materials Research Group, the portfolio of scientific expertise, the adequacy of facilities, equipment, and human resources, and the dissemination of outputs are all similar to those just described for the Microcopy and Microanalysis Research Group. High-quality research is being performed in some very select fields, but the biggest challenge for the Nano Materials Research Group is that its thrusts and goals represent only a small portion of global interests within a huge field of great international interest and importance. It is difficult to be recognized as a world leader when the overall scale of many other nano-materials research groups is so much broader and deeper.

The Surface and Trace Chemical Analysis Group has an impressive suite of commercially based instruments, including secondary ion imaging and tomographic atom probe analysis coupled with laser excitation of surface atoms.

In the Synchrotron Science Group the beamlines currently being supported include the current beamline X23A2 (4.7 to 32 keV) x-ray absorption fine structure spectroscopy (XAFS); beamline U7A

(0.175 to 1.3 keV) near-edge x-ray absorption fine structure spectroscopy (NEXAFS); and beamline X24A (0.7 to 5.0 keV) hard x-ray photoelectron spectroscopy (HAXPES) at the NSLS I. The energy range covers the entire periodic table, which enables the study of a broad range of technological materials, including inorganic and organic semiconductors, photovoltaics, self-assembled monolayers (SAMs), biological and environmental materials, batteries, catalysts, fuel cells, polymers, superconductors, ferroelectrics, and ferromagnets. This facility provides unique opportunities for collaborative research within the MMSD, with MML personnel across divisions (including the Boulder, Colorado, facility), and with the broader user community, including numerous industrial partners.

Across the MMSD, the internal assessment of output seems satisfactory and recognizes the different expectations placed on individuals, but some staff expressed concern that these division-level assessments were not always understood at the MML level and above. For example, an instrument developer who takes years to build a unique tool that results in a handful (or less) of publications during that time, appears to be at a disadvantage for promotion, merit pay, fellow status, and other forms of recognition compared to more academically oriented researchers whose H index in high-impact journals is immediately recognized.

The scientific staff in the MMSD expressed an impression that the group is disproportionately impacted by the IS tax because it is heavily reliant on equipment with service contracts. The IS tax also affects contracts with academic associates. It adds to indirect costs at university and industry partners, reducing the value of these partnerships. MMSD management needs to examine with MML management whether this overhead structure is achieving its aims and needs to communicate with staff about why the structure is in place, how it benefits the groups, and how perceived concerns can be addressed. The fact that recent capital investment rates are well below depreciation rates is another challenge. Given these trends, the equipment/scientist ratio is at risk of decreasing significantly, which would be counterproductive to the mission of the division. There are, then, concerns about the division’s ability to maintain current service contracts and buy new expensive instruments that will keep the MMSD at the scientific forefront. The possibility that the central MML budget might be a source for such new instruments needs to be communicated more clearly to the bench scientists who are unaware of this option.

Procurement and legal issues are perceived by some staff as day-to-day threats to carrying out the missions of the groups in the MMSD. There is also some concern about the lack of travel opportunities for junior scientists, although the situation appears better than at some other federal facilities.

The Securities Technologies Group lost $2 million of its $3.8 million scientific and technical research and services (STRS) budget when the reorganization of the MML occurred. This cut, together with the IS tax, inhibits the group’s ability to engage in meaningful collaboration with academic associates. Legal delays have cost the group a motivated industrial partner. If the Securities Technologies Group does not receive sufficient support to meet its technical goals, its portfolio might appropriately be integrated into the portfolios of other adequately resourced groups.

In general, the facilities are adequate for the division’s mission, with the principal difficulty being the dispersal of the division in buildings across the NIST site. There appears to be no imminent solution to such scattered facilities, and so the growth of collaboration between cross-cutting thrusts might prove less than ideal. Scientific instrumentation is generally of extraordinary quality across many of the groups. Some pieces of equipment are unique and some world leading, matching the quality of the staff. The human resources are highly accomplished, collaborative, and effective in their equipment usage. Common to all groups, there are opportunities for more communication with MML leadership on issues such as procurement, the IS tax, and travel processes.

DISSEMINATION OF OUTPUTS

The MMSD is highly effective in disseminating its program output. It has a successful publication record that corresponds to roughly one publication per person per year. This may appear

modest compared to other top-tier research institutions, but the unique mission of the MMSD yields output in many areas other than publication. The division’s publications are in a broad range of fields, reflecting its diverse research activities, and over the past year have included publications in high-impact journals such as Nature Materials, Nano Letters, ACS Nano, Advanced Energy Materials, Advanced Functional Materials, Chemistry of Materials, and Small. Many of the papers are coauthored with researchers outside NIST; this indicates successful collaborations.

Patenting is secondary to many other success metrics for almost all MMSD staff researchers, and there were only two division patents in the past year.

The MMSD works closely with industrial partners. There have been three cooperative research and development agreements (CRADAs), including one with the Dow Chemical Company on synchrotron materials characterization and one with Intel-ENIAC on emerging nanoscale interface and architecture characterization. These CRADAs are important contributors to the division’s research portfolio.

The division has developed three commercial swipe technologies, and three printer systems have been commercialized. The division sells approximately 1,700 reference materials units per year of almost 80 different types. The total revenue is about $300,000 per year. These materials cover a variety of needs, including x-ray diffraction characterization and calibration, particle size (including nanoparticle sizing), glass viscosity, refractive index, surface area, and chemical composition. About 20 percent of the customers are from academia; 20 percent from state, local, and federal governments; and 60 percent from industry. Examples include SI-traceable SRMs for calibration of varying diffraction measurement methods. This product is highly effective, and there is hardly an x-ray diffractometer in the world that does not use the NIST standard. Roughly a third of new instruments sold worldwide include a NIST standards diffraction package.

The MMSD also provides SRD covering crystallographic and structural information, phase diagrams, surface spectroscopy, ceramic properties, and x-ray and image analysis, all of which are used worldwide. These standards are a major resource for researchers, and the MMSD expends enormous efforts to incorporate image processing and theoretical/statistical methods within materials databases to expedite experimental data standardization and evaluation.

MMSD representation on standards-setting committees is outstanding and is a significant output of the division. Twenty-eight MMSD staff members actively participate on committees in 125 international standards organizations (primarily ASTM and ISO). This participation includes standards committee leadership, with the following subcommittee chair positions: ASTM International Committee E56 on Nanotechnology; ASTM F12.60 Committee on Controlled Access Security, Search, and Screening Equipment; ASTM F23.25 Committee on Ballistic Hazards; ASTM E54.01 Subcommittee on CBRNE Sensors and Detectors; IEC TC85 (PT62792, MT18, WG22) Committee on Measuring Equipment for Electrical and Electromagnetic Quantities; and IEEE TC10 (subprobe standards, subpulse technology) Subcommittee on Waveform Generation, Measurement, and Analysis.

The MMSD has generated for other agencies significant outputs that for security reasons are not included in its list of publically available publications. These include 115 reports of analysis, 15 reports on the status of projects, and 4 written and 3 oral research and development reports that summarize the status and outputs of projects.

Since the beginning of 2014, the division has conducted significant outreach and training for visitors, including 72 tours for 485 hosted visitors. The division has hosted more than 1,500 visitors since 2009.

OVERALL ASSESSMENT

The strong collaboration across the groups that existed before the formation of the MMSD has continued. The management expressed its commitment to making the division more than the sum of its parts, but this remains a challenge. The MMSD appears well managed, with an enthusiastic cadre of

administrators and active researchers who perform high-quality science. The research activities are nicely balanced between basic research, where the primary output is peer-reviewed publications, and technical programs that serve the standards mission of NIST. While improvements in the demographic diversity of the division are needed, there is strong evidence that the female leaders are well respected and contribute fully at the leadership table. The morale of staff, from postdoctoral researchers through emeritus fellows, appears high. The MMSD is successfully maintaining a culture that fosters loyalty, partly because staff have the opportunity to focus primarily on research. Overall, the quality of the research in several traditional standards-related areas is world leading. For example, the Microscopy and Microanalysis, the Surface and Trace Chemical Analysis, the Materials Structure and Data, and the Synchrotron Science groups are all at the top of their fields in the United States, have been recognized as such by their peers for many years, and are acknowledged internationally as being among the top 10 in their fields worldwide. In its chosen niche area, the Nano Materials Group is also world leading. The Materials Structure and Data Group is the acknowledged source of phase diagram and crystal structural information around the world. The Microscopy and Microanalysis Group and the Surface and Trace Chemical Analysis Group have long been recognized as the organizations that set the world standards for quantitative electron imaging, x-ray analysis, and secondary ion imaging and analysis.

FINDINGS AND RECOMMENDATIONS

Current expenditures for the acquisition of new equipment and for maintaining existing facilities are inadequate to support the high-quality programs. This is a particular challenge for the Synchrotron Science Group, which is a jewel in the crown of the MMSD.

The quality of the junior staff is excellent. It reflects the success of the National Research Council postdoctoral program in attracting young talent to NIST and also reflects the success of senior staff and management in mentoring the new hires.

The researchers reported that they are increasingly burdened by administrative duties (e.g., procurement and legal processes) and responding to unfunded mandates such as the Digital Accountability and Transparency Act (DATA).

The division’s eight well-established groups are spread across multiple buildings. For this reason, the researchers tended to identify with their particular group rather than with research thrusts. The development of a more coherent division is slowed by this distribution of groups and facilities across multiple buildings.

The core strength of the MMSD is its very long-term investment in basic research and the iterative development of new instruments to advance measurement science. Over the past decade, a shift to short-term, customer-driven research and responses to unfunded mandates are eroding this long-term strategy and are promoting more short-term, applied research in areas where the MMSD is less competitive compared to academia and other national laboratories.