Abstract
A simple statistical analysis which yields the precision, resolution, accuracy and trueness of diffraction-based lattice strain measurements is discussed. The procedure consists of measuring the thermal expansion induced in each component of an ideal non-reacting two-component crystalline powder sample in situ. One component, with a high coefficient of thermal expansion (CTE), serves as an internal thermometer. The quantities of interest are obtained by determining the smallest statistically significant thermal lattice strain which can be detected through diffraction analysis in the second, low-CTE, component in response to controlled temperature changes. This procedure also provides a robust check of the alignment of the diffraction system and is able to reveal the presence of systematic errors. The application of this technique to a time-of-flight engineering diffractometer/strain scanner is presented.
| Original language | English |
|---|---|
| Pages (from-to) | 494-511 |
| Number of pages | 18 |
| Journal | Journal of Applied Crystallography |
| Volume | 53 |
| DOIs | |
| State | Published - Apr 1 2020 |
Funding
ICN acknowledges and thanks the Los Alamos and Oak Ridge National Laboratories for partially funding the two sabbaticals, during 2011–2012 at LANL and 2018–2019 at ORNL, respectively, when this work was performed. Additional sabbatical funding was provided by Columbia University. This work benefited from the use of the Lujan Neutron Scattering Center at LANSCE, which was funded by the Department of Energy (DOE), Office of Basic Energy Sciences. At the time Los Alamos National Laboratory was operated by Los Alamos National Security LLC under DOE contract DE-AC52-06NA25396. The analysis part of this research, at ORNL’s High Flux Isotope Reactor and the Spallation Neutron Source, was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy.
Keywords
- accuracy
- precision
- resolution
- time of flight
- trueness