The thermal properties of germanium and silicon in condensed state

New experimental data are presented on the thermal expansion of melts of ge rmanium and silicon, and on changes in their density during crystallization ; these data are obtained by exposing samples to a narrow beam of gamma rad iation. It is shown that the density polytherm of liquid germanium is nonli near. The causes of this phenomenon are discussed. The electronic component s of the density jumps for Ge and Si on the crystal-melt phase transition a re estimated. The experimental results and the most reliable literature dat a on the density of crystalline semiconductors are used to compile consiste nt tables of the thermal properties of germanium and silicon in the solid a nd liquid states in a wide temperature range from 0 to 1900 K (for Si) and from 0 to 2275 K (for Ge).