Amorphization of Ge–GeSe mixtures in mechanical alloying process

Structural changes by mechanical stress of a planetary ball mill have been investigated in Ge–GeSe eutectic mixtures. Amorphization of the GeSe compound was accomplished after 27 h of grinding under the present condition. Pair distribution function g(r) of the amorphous GeSe is calculated. The nearest neighbour Ge–Se distance is 2.37 Å, which is smaller than that of crystalline GeSe. The only crystalline GeSe phase in the eutectic mixtures selectively changes to the amorphous phase. Ge–GeSe alloying is not performed at the atomic level under the present condition, because the peak positions of interplanar spacings of GeSe are almost constant in the variation with grinding time. The decay rate of integrated intensities of (1 1 1) and (0 0 4) peaks of GeSe is evaluated. The amorphous transition energy related to the decay rate for the crystalline–amorphous transition of GeSe in the mixtures decreases with decreasing GeSe content.