title: Phase stability of lithium azide at pressures up to 60 GPa.
abstract: We studied lithium azide (LiN(3)) by x-ray diffraction and Raman spectroscopy at hydrostatic compression up to pressures above 60 GPa at room temperature. The results of x-ray diffraction analyses reveal the stability of the ambient-pressure C 2/m crystal structure up to the highest pressure. The pressure dependence of librational modes provides evidence for an order-disorder transition at low pressures (below 3 GPa), similar to the transition observed previously at low temperatures. The observed structure stability indicates that this transition is not associated with structural changes. The phase stability of LiN(3) is in contrast to that of sodium azide (which is isostructural at ambient pressure), for which a set of phase transitions has been reported at pressures below 50 GPa.
authors.affiliation: Max-Planck-Institute for Chemistry, Postfach 3060, D-55020 Mainz, Germany. Institute für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, D-55099 Mainz, Germany.
authors.forename: S A
authors.initials: SA
authors.lastname: Medvedev
authors.forename: I A
authors.initials: IA
authors.lastname: Trojan
authors.forename: M I
authors.initials: MI
authors.lastname: Eremets
authors.forename: T
authors.initials: T
authors.lastname: Palasyuk
authors.forename: T M
authors.initials: TM
authors.lastname: Klapötke
authors.forename: J
authors.initials: J
authors.lastname: Evers