Pressure-Induced Intercalation and Amorphization in the Spin-Peierls CompoundCuGeO3

High pressure Raman scattering and optical microscopic studies on ${\mathrm{CuGeO}}_3$ have been carried out in the diamond cell at room temperature. A pressure-induced reversible transition presumably due to intercalation of alcohol is observed at 7 GPa with 4:1 methanol ethanol as pressure medium. In this transition the sample dimension along the $b$ axis visibly decreases by about 20%, preserving the single crystal nature. Such behavior is rather unique and unusual. Further, a pressure-induced reversible amorphization transition occurs near 15 GPa. Intercalation with ${\mathrm{H}}_2\mathrm{O}$ is also indicated near 9 GPa with no change in the sample dimension.