Electrical Properties and Thermal Expansion of the Laves Phases, CaMg2 and MgCu2

摘要

Electrical resistivities, temperature coefficients of resistivity, and Hall coefficients have been measured on single crystals of hexagonal CaMg2 and on polycrystals of cubic MgCu2. The magnitudes of the measured values fall in the range normally observed in metals. In contrast, measured values for the coefficients of thermal expansion are slightly higher than those observed in metallic elements. Appreciable scatter in measured resistivities on different specimens was observed and is presumably due to variations in the degree of crystalline perfection. For CaMg2 the measured Hall coefficients and the temperature coefficients of resistivity and of thermal expansion show only a small degree of anisotropy. The sign of the Hall coefficients was found to be positive for CaMg2 and negative for MgCu2; this is consistent with previous measurements of magnetic susceptibility made on MgCu2 and its alloys.