Pressure-Induced Amorphization of CuGeO₃

Abstract

Amorphization under pressure has been observed in CuGeO₃ at room temperature. It is apparently revealed by the change in color from blue to green. The amorphous feature in the green-colored phase was demonstrated by X-ray diffraction measurement, in which the Bragg peaks almost disappeared and a halolike background is observed. An exothermic reaction due to crystallization was observed at about 580°C in the amorphous phase by differential thermal analysis. Antiferromagnetism in the crystalline CuGeO₃ is replaced by Curie-paramagnetism in the amorphous one.