# Research Activity: Structure and Composition of Materials

Division: Materials Sciences and Engineering

Primary Contact(s): Jane G. Zhu
([jane.zhu@science.doe.gov](../altaf.carim@science.doe.gov);
301-903-3811)

Team Leader: Helen Kerch (Acting)

Division Director: Harriet Kung

**Portfolio Description:**

This activity supports basic research in condensed matter physics and
materials physics using electron scattering and microscopy and scanning
probe techniques. Research includes experiments and theory to understand
the atomic, electronic, and magnetic structures of materials.
Increasingly important are the nanoscale structures and the structure
and composition of inhomogeneities including defects, interfaces,
surfaces, and precipitates. Advancing the state of the art of electron
beam and scanning probe techniques and instrumentation for quantitative
microscopy and microanalysis is an essential element in this portfolio.

**Unique Aspects:**

This activity is driven by the need for quantitative characterization
and understanding of materials structure and its evolution over atomic
to micron length scales. It is a major source of research in the United
States that is focused on structure and defects in atomic configurations
over all length scales and dimensionalities, and is the nation's only
investment in large-scale, comprehensive microscopy research groups
which bring together science-driven investigators whose focus is the
development and implementation of a wide variety of electron scattering
and scanning probe techniques. Therefore, it supports the facility
stewardship role of the Department of Energy (DOE) by enabling full
exploitation of the BES three electron microscopy user centers. The
portfolio includes characterization and analysis of materials by
transmission and scanning transmission electron microscopy, atom-probe
field ion microscopy, scanning probe microscopies, spin polarized low
energy electron microscopy, electron beam holography and tomography,
convergent beam electron diffraction, ultrafast electron diffraction and
microscopy, and other state of the art methods. Research results are
increasingly coupled with first-principles theory, which offers
quantitative insights into the atomic origins of materials properties.

**Relationship to Other Programs:**

The structure and Composition of Materials program interfaces with other
programs in BES, other offices in DOE, and other federal agencies.

BES:

-   Coordinated with activities under Mechanical Behavior and Radiation
    Effects, Physical Behavior, Synthesis and Processing, X-Ray and
    Neutron Scattering, Condensed Matter Physics, Materials Chemistry
    and Biomolecular Materials, Catalysis, Electron-beam
    Microcharacterization Centers, and Nanoscience Centers

-   Linked with the Computational Materials Sciences Network

Other offices in DOE:

-   Hydrogen Fuel Initiative (HFI)

-   Energy Materials Coordinating Committee (EMaCC)

Interagency:

-   Interagency Coordination and Communications Group for Metals
    (NSTC/CT/MatTec)

-   Interagency Coordinating Committee on Structural Ceramics
    (NSTC/CT/MatTec)

-   National Nanoscience Initiative (NNI)

**Significant Accomplishments:**

World class scientific achievements in this program represent the
leading U.S. capabilities for structural and compositional
characterization at atomic length scale, coupled with advances in
detectability limits and precision of quantitative analytical
measurement. Accomplishments include:

-   The successful correction of electron microscope lens aberrations
    has doubled resolution in just a few years, allowing for the first
    time the direct imaging of materials at sub-Angstrom resolution.

-   The first spectroscopic imaging of single atoms within a bulk solid
    using an aberration-corrected scanning transmission electron
    microscope. The ability to collect electron energy loss spectra from
    an individual atom allows not only elemental identification, but
    also the determination of chemical valence and its bonding
    configuration or local electronic structure through analysis of the
    fine structure of the spectroscopic absorption edge.

-   Combined scanning probes, electron microscopy, and theoretical
    calculations to reveal an unexpected behavior: ferroelectric
    ordering in a non ferroelectric compound (SrTiO~3~) induced by a
    grain boundary.

-   Invented new local probes: scanning impedance microscopy and
    nanoimpedance spectroscopy.

-   Developed advanced computer processing methods for a through-focus
    series of electron microscope images to achieve an \"information
    limit\" that exceeds the resolution of the best-ever single optimal
    image. This method enabled the first imaging of the light
    non-metallic elements-carbon, nitrogen, and oxygen.

-   Developed a new interferometric electron beam technique to measure
    atomic displacements in crystals with unprecedented picometer
    accuracy.

-   Developed and demonstrated new quantitative methods to image and
    measure the distribution of valence electrons in solids, which have
    made significant contributions to the understanding of electronic
    transport in high temperature superconductors.

-   Conceived and constructed the first three-dimensional, energy
    compensated, position sensitive atom microprobe that permits
    compositional imaging and depth analysis with atomic resolution.

-   Refined Atomic Location by Channeling Enhanced Microanalysis in an
    electron microscope to precisely define locations of various atomic
    elements and reveal an unprecedented level of information in a
    variety of technologically important alloys.

-   Pioneered the application of electron beam holography to image and
    measure the grain-boundary potentials in vital ceramics such as
    superconductors, ferroelectrics, and dielectrics by exploiting the
    sensitivity of highly coherent electron waves to local electric
    fields.

-   Developed the highest spatial resolution and lowest elemental
    detectability limit in-situ electron energy loss spectroscopy.

-   Developed a new electron microscopy technique known as \"fluctuation
    microscopy\" that shows atomic arrangements in amorphous and glassy
    materials better than any alternative method.

-   Incorporated a controlled nanoindentation apparatus within a
    transmission electron microscope for the first time, permitting the
    simultaneous atomic-scale observation and mechanical testing of
    nanoscale sample regions.

    -   Developed the \"Embedded Atom Method\" that revolutionized the
        field of computational materials science by permitting
        large-scale simulations of atomic structure and evolution. It is
        currently being used by more than 100 groups worldwide and has
        resulted in over 1100 published works with over 2700 citations
        to the original work.

**Mission Relevance:**

The fundamental properties of materials used in all areas of energy
technology depend upon their structure and composition. Performance
improvements for environmentally acceptable energy generation,
transmission, storage, and conversion technologies likewise depend upon
these characteristics of advanced materials. This dependency occurs
because the spatial and chemical inhomogeneities in materials (e.g.,
dislocations, grain boundaries, interfaces, magnetic domain walls, and
precipitates) determine and control critical behaviors such as fracture
toughness, ease of fabrication by deformation processing, charge
transport and storage capacity, superconducting parameters, magnetic
behavior, and corrosion susceptibility. Quantitative analysis of
nanoscale structures is crucial to the progress of nanoscale science--a
major thrust in BES. The program is also relevant to the DOE HFI through
the structural determination of nanostructured materials for hydrogen
storage and solar hydrogen generation.

**Scientific Challenges:**

Major scientific challenges in the Structure and Composition of
Materials program are: quantitative analysis of nanoscaled structures in
nanomaterials, including the atomic, electronic, and magnetic
structures; understanding nanoscale interactions and phenomena;
understanding correlation between electrons and spins at nanoscale;
determination of interface structures between dissimilar materials;
understanding the role played by the interface structure in the
evolution of microstructures; determination of local inhomogeneity and
structure disorder; understanding the link between
interface/surface/defect structures and materials properties;
understanding of the structure and dynamics of amorphous materials,
especially the short- and long-range order effects; development of
ultrafast electron microscopy with high resolution both spatially and
temporally to study the atomic level mechanisms during structural
transformations; developing the ability to measure the distribution of
valence electrons with sufficient accuracy; and the application of first
principles theory to understand and predict the structures of real
materials. To address these challenges, new state-of-the-art
experimental and theoretical techniques will need to be developed. It is
our long term goal to invent multiscale characterizations tools and be
able to link structural evolution, dynamics, and electronic behavior
with first principles understanding of structure.

**Funding Summary:**

**Dollars in Thousands**

**[FY 2005]{.underline} [FY 2006]{.underline} [FY 2007
Request]{.underline}**

24,907 16,943 22,245

> **[Performer]{.underline} [Funding Percentage]{.underline}**
>
> DOE Laboratories 77%
>
> Universities 23%

These are percentages of the operating research expenditures in this
area; they do not contain laboratory capital equipment, infrastructure,
or other non-operating components.

**Projected Evolution:**

In the near term, program evolution builds upon recent accomplishments
that span a wide range of areas including advances in
microcharacterization science, the characterization of nanostructured
materials, and detailed models of magnetic and structural phenomena.
Electron scattering and scanning probe approaches supported by this
program have higher spatial resolution than most other materials
characterization techniques and are thus unique in their ability to
characterize discrete nanoscale and nanostructured regions within the
interiors of samples. Characterization of semiconducting,
superconducting, magnetic, and ferroelectric materials benefits greatly
from these abilities and from other research supported in this program.
Concurrently, new frontiers in characterizing and understanding the
microstructure and microchemistry of materials are being opened with the
creation of novel characterization techniques.

# Development of advanced electron microscopy techniques will be continued, which will be partnered with the three electron-beam microcharacterization centers that were built up in this program and are now in the Electron Beam Microcharacterization activity. The enormous improvement in sensitivity will provide an array of opportunities for groundbreaking science. These include the possibilities of atomic-scale tomography, single-atom spectroscopic detection and identification, and increased experiment volumes within the microscope and consequently greater in-situ analysis capabilities (under perturbing parameters such as temperature, irradiation, stress, magnetic field, and chemical environment). 

New methods and approaches addressing the scientific challenges will
lead to the development of unique new analysis tools and breakthroughs
in materials. The combined new experimental and theoretical capabilities
will enable the fundamental understanding of atomic origins of materials
properties. Significant advances will be made in the detailed
understanding of the mechanisms by which grain boundaries, interfaces
and defects in metals, ceramics, semiconductors, and polymers influence
the properties and behavior of these materials. Implementing
nanostructural control over these mechanisms will revolutionize the
fundamental principles of materials design.