Measurements and Predictions 

of Local Structure

CERAMICS

Our goal is to provide analytical tools that allow measurement 

and prediction of local structure to enable the development of 

ceramic materials for electronic applications. Under this project, 

we develop data analysis methods for quantitative determination 

of local structure from multiple experimental techniques, and 

theoretical methods for prediction of local atomic configurations 

from first principles.

Objective

Impact and Customers

• The availability of methods and analytical tools for measuring local structure will accelerate the formulation of 

structure-property relations for advanced electronic ceramics and allow more rapid selection and optimization of 

these materials, thereby decreasing the development time for new electronics devices.

• Computer software for simultaneous refinements of atomic arrangements 

using diffraction and x-ray absorption fine structure data was developed 

and transferred to our partners at the ISIS pulsed neutron and muon source 

in the United Kingdom, for web posting. 

• An invited review article in Science, which described the problem of solving 

structure at the nanoscale, followed by input from scientists from industry 

(e.g., GE, Exxon/Mobil, Ford, IBM, Sematech), government agencies, and 

universities, inspired a NIST workshop, “Measurement Needs for Local 

Structure Determination”, that took place in February, 2008.

Approach

Materials Science and Engineering Laboratory

Electronic ceramics enable applications in the computer, data storage, and 

wireless communication sectors. The properties of many of these ceramics 

are critically dependent on deviations of local atomic arrangements from the 

global average of the crystal. No single measurement technique can provide 

an accurate description of the local structure. Therefore, our efforts focus 

on developing analytical tools (methods and software) that allow integration 

of measurements from multiple experimental methods, and theory to enable 

accurate and comprehensive determination and prediction of local atomic 

configurations. Specifically, we develop methods and software for structural 

refinements using simultaneous fitting of diffraction and x-ray absorption data, and modeling tools for ab initio

simulations of diffuse scattering in systems with nanoscale order, Raman spectra in systems with local disorder, and 

point defects and their complexes in oxide dielectrics. All of this input is needed for the determination of local structure 

in electronic ceramics.

852-08-83c
Materials Science and Engineering Laboratory

Electronic ceramics with the perovskite 

structure are widely used in functional device 

applications. Most of the technologically 

relevant perovskites are solid solutions and 

therefore their local atomic arrangements 

necessarily deviate from those described 

by the average crystallographic positions. 

These local deviations control the functional 

properties of such perovskites; therefore, 

accurate knowledge of the local structure 

is needed to determine structure-property 

relationships.

Relaxor ferroelectrics represent a prominent 

example of technologically useful materials 

that crystallize with perovskite-like 

structures. The origin of the relaxor behavior 

has been a topic of intense research for 

over a decade. These materials exhibit 

both chemical and polar inhomogeneity 

that give rise to diffuse X-ray and neutron 

scattering, which therefore provide useful 

probes of local structure. We have greatly 

improved existing models of the classical 

relaxor ferroelectric Pb(Sc0.5Nb0.5)O3 by 

developing simulations of diffuse scattering 

based on first-principles calculations. Our 

simulations reproduced major features 

of experimental diffuse scattering. The 

relaxor phase exhibits “butterfly” and 

rod-like shapes of diffuse scattering 

around the [100] and [110] reflections, 

respectively, whereas the high-temperature 

paraelectric phase exhibits radial diffuse 

streaks around all the Bragg peaks. We 

have determined that the rod and butterfly 

features arise from polar nanoregions, 

whereas the radial streaks originate from 

atomic displacements associated with 

chemical disorder. This work illustrates the 

power of a combined experimental and 

theoretical first-principles based approach 

to the local-structure problem.

We have significantly extended the 

capabilities of the software for combined 

quantitative refinements of local structures 

using simultaneous Reverse Monte Carlo 

fitting of the neutron and X-ray total 

scattering and X-ray absorption fine 

structure (EXAFS) data. The latest version of 

this software incorporates a new algorithm 

that allows for the explicit treatment of 

multiple-scattering effects in EXAFS thereby 

enabling accurate modeling of the EXAFS 

data over distances encompassing several 

coordination shells around the absorber 

atoms. The software was tested using 

several model systems, including Ni and 

the complex perovskite Sr(Al0.5Nb0.5)O3, 

and, as a next step, will be applied to 

the technologically relevant Ag(Nb,Ta)O3

dielectrics whose exploitable properties 

are dominated by local-structure effects.

In February 2008, we organized a NIST 

workshop on “Measurement Needs for 

Local Structure Determination in Inorganic 

Materials.” This 2-day meeting brought 

together experts in the key experimental 

and theoretical areas relevant to localstructure measurements. The group 

included representatives of several major 

industrial sectors, academia, government 

labs, DOE, and NSF. The participants 

unanimously agreed that solving the localstructure problem – an important frontier 

in materials characterization – necessitates 

a coordinated interdisciplinary effort that 

transcends the existing capabilities of 

any single institution, including national 

laboratories, centers, and user facilities. 

Development of methodology and 

software for: (1) combining inputs from 

multiple techniques and theory in a global 

modeling framework, and (2) theoretical 

modeling of nanoscale structures and their 

measurement responses, were identified 

as the highest priority issues.

Accomplishments

Benjamin Burton

Eric Cockayne

Victor Krayzman

Katharine Mullen

Terrell Vanderah

Igor Levin (Ceramics Division)

(301) 975-6142

igor.levin@nist.gov

www.nist.gov.ceramics

Learn More Publications

Billinge SJL and Levin I The Problem with Determining Atomic Structure at the Nanoscale

Science, 316: 561 (2007)

Levin I and Vanderah TA Workshop on Measurement Needs for Local-Structure

Determination in Inorganic Materials J. Res. Natl. Inst. Stand. Technol., 113: 321 (2008)

Krayzman V, Levin I, Woicik JC, Proffen T, Vanderah TA and Tucker MG A Combined Fit 

of Total Scattering and Extended X-ray Absorption Fine Structure Data for Local Structure 

Determination in Crystalline Materials J. Appl. Cryst., 42: 867-877 (2009)

Burton BP, Cockayne E, Tinte S and Waghmare UV The Effect of Nearest Neighbor [PbO] Divacancy Pairs on the Ferroelectric-Relaxor Transition in Pb(Sc0.5N0.5)O3 Phys. Rev. B, 

77: 144114 (2008)

Experimental and calculated diffuse scattering

Simultaneous fits of multiple types of data for 

Sr(Al0.5Nb0.5)O3