|
- Crystal structure information is gained for samples that are difficult (or impossible)
to synthesize in a form suitable for single crystal analysis
- Solid solutions and multi phase specimens can be characterized for atomic structure,
site occupancy, quantitative phase content, and microstructural characteristics.
- GSAS (General Structure Analysis System)
can combine data from different radiation sources
- neutron radiation - sensitive to light elements
- synchrotron radiation - high intensity, high resolution, tunable wavelengths
- conventional x-ray - convenient
|
|
Refined variables may include:
- structural parameters
- lattice constants
- atomic positions
- thermal parameters
- site occupancy
- instrumental broadening
- peak asymmetry
- Lorentz and polarization
- axial divergence
- background coefficients
- microstrain broadening
- crystallite size broadening
- quantitative phase analysis
|
Above: GSAS refinement on LaB6
(NIST SRM660) powder used to define laboratory instrumental parameters |
Below: Rietveld refinement using GSAS on
BaTiO3 powders provided crystallite size, microstrain and structural parameters
as a function of processing temperature.
(Safari and Akdogan, Rutgers University) |
 |
High Temperature X-Ray Diffractometer |
