X-ray Diffraction (XRD)

X-ray Diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of x-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the atomic decoration within the lattice planes. Consequently, the x-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. An online search of a standard database for x-ray powder diffraction patterns enables quick phase identification for a large variety of crystalline samples.

Evans Analytical Group’s® (EAG) multiple XRD systems are equipped with optical modules that can be exchanged, depending on the analysis requirement, without affecting the accuracy of positioning. It is simple to change between line and point focus of the x-ray tube, enabling simple switching from a regular XRD configuration to a high-resolution XRD configuration. Different combinations of optical modules enable the analysis of powders, coatings, thin films, slurries, fabricated parts, or epitaxial films. Qualitative measurements for phase identification can be carried out using the ICDD database.

Main Applications

• Identification/quantification of crystalline phase
• Measurement of average crystallite size, strain, or micro-strain effects in bulk and thin-film samples
• Quantification of preferred orientation (texture) in thin films, multi-layer stacks, and manufactured parts
• Determination of lattice parameters to quantify alloy content

Ideal Uses for XRD Analysis		Relevant Industries for XRD Analysis
Phase identification for a large variety of bulk and thin-film samples Detecting crystalline minority phases (at concentrations greater than ~1%) Determining crystallite size for polycrystalline films and materials Determining percentage of material in crystalline form versus amorphous Measuring sub-milligram loose powder or dried solution samples for phase identification Analyzing films as thin as 50 angstroms for texture and phase behaviors Measuring residual stress in bulk metals and ceramics		Aerospace Automotive Medical Implants Compound Semiconductor Data Storage Displays Electronics Industrial Products Lighting Pharmaceutical Photonics Polymer Semiconductor Solar Photovoltaics
Strengths of XRD Analysis		Limitations of XRD Analysis
Nondestructive Quantitative measurement of phase contents and texture orientation Minimal or no sample preparation requirements Ambient conditions for all analysis		Cannot identify amorphous materials No depth profile information Minimum spot size of ~50um