Low-Temperature Heat Capacity of Amorphous Germanium

Abstract

The heat capacity of amorphous germanium, measured between 2 and 30 K using a thermal-relaxation technique, is about 50% greater than that of crystalling germanium, but has a similar temperature dependence. We infer an amorphous phonon density of states at low frequencies given by the TA crystalline density of states, broadened, and with all modes reduced in frequency by a factor of 0.84. A re-examination of Raman measurements in amorphous germanium shows them to be consistent with this result.