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Crystal structure evolution of BaBrCl and BaBrCl:5%Eu up to 1073 K by neutron diffraction
Author(s) -
Onken Drew R.,
Williams Richard T.,
Perrodin Didier,
Shalapska Tetiana,
Bourret Edith D.,
Tremsin Anton S.,
Vogel Sven C.
Publication year - 2018
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/s1600576718002807
Subject(s) - europium , neutron diffraction , thermal expansion , materials science , anisotropy , crystal structure , atmospheric temperature range , diffraction , crystallography , crystal (programming language) , rietveld refinement , melting point , chemistry , optics , luminescence , thermodynamics , physics , composite material , optoelectronics , programming language , computer science
BaBrCl:Eu is a promising scintillator material; however, the crystal growth yield must be improved for it to become commercially viable. This study measures strain accumulations in the crystal lattice which can contribute to cracking during post‐growth cooling. Neutron diffraction is used to measure the crystal structure of undoped and 5 mol% europium‐doped BaBrCl from 303 to 1073 K, approaching the melting point. Rietveld analysis of these data provides the temperature dependence of the thermal and chemical strain in BaBrCl. In particular, anisotropic thermal expansion is measured, with expansion along the b axis nearly double the expansion along the a and c axes. Additionally, the chemical strain from the incorporation of europium atoms peaks around 673 K, explaining cracking frequently observed in that temperature range.