Neutron scattering investigation of pressure-induced phase transitions in Li and Ba

Author(s): Markus Prem, Maciej Krystian, Wolfgang Pichl, Gerhard Krexner, S Klotz
Abstract: The elemental alkali metals as well as the earth-alkaline metal barium undergo phase transitions from an ambient bcc structure to close-packed structures (fcc or hcp, respectively) in a largely varying pressure range from 4.5 GPa in Cs up to more than 50 GPa in Na. Little is known about the mechanisms of these pressure-induced phase transitions. In particular, it is an open question whether the and transformations are related to similar phase transitions at ambient pressure and low temperatures which occur in Li and Na but are absent in the heavy alkali metals and in Ba. In the present work, we have adapted the Paris-Edinburgh pressure cell for neutron scattering studies on single crystals of Li and Ba. It was found that under carefully chosen experimental conditions almost hydrostatic loading of Li and Ba up to about 7 GPa is possible. We describe the experimental methods which have allowed us to overcome the technical difficulties and report the first results of elastic neutron scattering on Li and Ba and inelastic neutron scattering on Li. Œ 2005 IOP Publishing Ltd.
Organisation(s): Department of Mineralogy and Crystallography
External organisation(s): Université Paris VI - Pierre-et-Marie-Curie
Journal: Journal of Physics: Condensed Matter
Volume: 17
Pages: 3165-3171
No. of pages: 7
ISSN: 0953-8984
DOI: https://doi.org/10.1088/0953-8984/17/40/020
Publication date: 2005
Austrian Fields of Science 2012: 103015 Condensed matter
Portal url: https://ucrisportal.univie.ac.at/en/publications/efea167a-2843-45bd-97f3-33a639f9ef2d

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