Gallium Anisotropy and Crystal Structure

Abstract

AN earlier communication¹ directed attention to the ease with which single crystals of gallium could be produced and to the highly anisotropic properties of the specimens so obtained. The room temperature electrical conductivities as determined for the three mutually perpendicular axial directions were in the ratios of 1:3.2:7, and the corresponding expansion coefficients were in the ratios of 1:0.7:1.9. At that time, the axial directions had been related to the geometrical form and positioning of the seed crystal used when growing the specimens. The seed crystal had the symmetrical pyramidal form which is characteristic of crystals formed from liquid gallium when cooled to some 10° C. below the normal melting point. The axial direction giving the low conductivity had been found to coincide with the geometrical axis passing through the well-defined crystal point, while the other two axial directions coincided with the diagonals of the approximately square base of the pyramid.