Absence of pressure-induced amorphization in LiKSO4

作者：Machon D^*; Pinheiro C B; Bouvier P; Dmitriev V P; Crichton W A

来源：Journal of Physics: Condensed Matter , 2010, 22(31): 315401.

DOI：10.1088/0953-8984/22/31/315401

Angle-resolved synchrotron radiation diffraction was used to investigate lithium potassium sulfate (LiKSO4) crystals under high pressure. We confirm that the title compound undergoes three phase transitions, alpha -> beta, beta -> gamma and gamma -> delta, observed at around 0.8 GPa, 4.0 GPa and 7.0 GPa, respectively. Two competitive structures are proposed for the beta-phase after powder diffraction data Rietveld refinements: an orthorhombic (space group Cmc2(1)) or a monoclinic (space group Cc) structure. These structures correspond to the models of the low temperature phases. The gamma-phase is indexed by a monoclinic structure. Finally, the delta-phase is found to be highly disordered. No evidence of any pressure-induced amorphous phase was observed up to 24 GPa, even under imposed highly non-hydrostatic conditions, contrary to previous propositions.

• 出版日期2010-8-11