Tkachev SN, Manghnani MH, Williams Q. In situ Brillouin spectroscopy of a pressure-induced apparent second-order transition in a silicate glass.
PHYSICAL REVIEW LETTERS 2005;
95:057402. [PMID:
16090919 DOI:
10.1103/physrevlett.95.057402]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2004] [Indexed: 05/03/2023]
Abstract
Brillouin scattering measurements of a silicate glass, carried out at high pressures in the diamond anvil cell, show a dramatic increase in the pressure dependence of longitudinal velocity, and a discontinuity in the compressibility of the glass at about 6 GPa. While a first-order phase transition has been documented under pressure within amorphous ice, we demonstrate that an apparent second-order transition to a new, structurally distinct amorphous phase can occur via the abrupt onset of a new compressional mechanism, which may be triggered by a shift in polymerization of the glass or an onset of a change in coordination of silicon, within pressurized amorphous silicates.
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