Pressure-Induced Amorphous Transition of Li₂Ge₇O₁₅ Crystal

Pressure-induced amorphous transition of Li₂Ge₇O₁₅ (LGO) crystal has been investigated by using in situ high pressure energy dispersive x-ray diffraction with synchrotron radiation at the pressure up to 21.6 GPa. Diamond anvils were used to generate high pressure. Pressure was measured in terms of the diffraction of Pt as an internal pressure standard. The crystal structure of LGO is an orthorhombic lattice at atmospheric pressure. According to the high pressure x-ray diffraction results, new diffraction lines begin to appear and LGO undergoes an intermediate phase transition at the pressure of 12.9 GPa. But, the diffraction lines disappear wholly and LGO becomes an amorphous phase at the pressure of above 14.8 GPa. This amorphous transition is irreversible.