training for advanced research


Glossary terms about Phase

Frequently used term for a sample component. Phases can be crystalline or amorphous compounds.

13 pages mention Phase

Analysis of data
Qualitative powder diffraction involves the identification of a phase or phases in a specimen by comparison with single-phase X-ray powder diffraction patterns compiled in a database called the Powder Diffraction File (PDF-2). 
Background information
Since then it has been applied to chemical analysis, stress and strain measurement, the study of phase equilibria, measurement of particle size, as well as crystal structure. 
However, at the right distance and angle these patterns can be in-phase with one another and cause constructive interference. 
How to process XRD files in EVA
Start with the elements suspected to be present in the major phase in the sample. 
Interesting facts
It can, therefore, be used to measure the crystalline content of materials; identify the crystalline phases present (including the quantification of mixtures in favourable cases); determine the spacing between lattice planes and the length scales over which they persist; and to study preferential ordering and epitaxial growth of crystallites. 
Nobel prizes for research with X-Rays
Computer programs exist to do this quickly and efficiently, and can reveal information about the sample including d-spacing, elements that are present and crystalline phases. 
Powder diffraction
Crystal symmetry is not obvious from the pattern. Multiphase mixtures complicate the issue. 
Sample preparation
The recommended size range is around 1-5µm (Klug and Alexander, 1974, Cullity, 1978, Brindley, 1980), especially if quantification of various phases is desired. 
Secondary optics
Step-by-step instructions to use the Bruker D8 advanced research XRD
Using the machine