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Energy‐dispersive measurements of diffracted synchrotron radiation as a function of pressure: applications to phase transitions in KCl and KI
Author(s) -
Skelton E. F.,
Kirkland J.,
Qadri S. B.
Publication year - 1982
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s002188988201139x
Subject(s) - synchrotron radiation , diffraction , synchrotron , phase (matter) , detector , optics , diamond anvil cell , phase transition , x ray crystallography , materials science , chemistry , analytical chemistry (journal) , physics , thermodynamics , organic chemistry , chromatography
Extensive details are presented of an experimental system consisting of a diamond‐anvil pressure cell, a Si(Li) detector, a four‐axis micropositioning system, and detection electronics assembled for performing energy‐dispersive X‐ray diffraction measurements with a synchrotron radiation source. Procedures for aligning and calibrating the system at the synchrotron facility are presented and the system is used to examine the first‐order structural phase transitions in both KCl and KI. Structural information has been obtained with this system from the high‐pressure environment in a fraction of the time normally required. Diffraction peaks could be identified and measured to an accuracy of ±0.1% within 200 s and to an accuracy of ±0.4% within 0.5 s. Optimum ranges for diffraction angles and X‐ray photon energies are reported. Volume compressibilities of KCl and KI in the low‐pressure ( B 1 structure) and the high‐pressure ( B 2 structure) phases are given along with information about the hysteresis loop associated with this transition.