Our objective is the development of Standard Reference Materials (SRMs) and quantitative, reproducible, and accurate measurement methods for characterization of any structure possessing spatial order on the scale of X-ray wavelengths. Such SRMs and measurement methods will aid in the development of new crystalline materials and devices made from them. Therefore, the impact of this project includes pharmaceuticals, ceramics, metals, semiconductors, and polymers.
Diffraction techniques can provide data on a number of sample characteristics. Therefore, the method of certification and the artifact itself are chosen to address a specific measurement issue pertinent to a diffraction experiment. NIST diffraction SRMs may be divided into five groups: Line Position, for calibration of the angle 2θ; Line Profile, for microstructure analysis; Instrument Response, for calibration of angle and intensity; Quantitative Analysis, for measurement of phase abundance; and Thin Film SRMs for measurement of thickness, surface roughness, and density of layered structures. The most common use of NIST SRMs is for calibration of diffraction line position. This requires that the SRM is certified with respect to lattice parameter. This length must be measured in a manner that is traceable to the International System of Units (SI) meter through a robust and transparent measurement chain. A major component of our effort consists of developing the capability for performing traceable measurement of lattice parameters for thin films and powders.