Temperature Dependence of Susceptibility of Zinc, Cadmium, and Gamma-Brass

Abstract

The temperature dependence (14\ifmmode^\circ\else\textdegree\fi{}K-373\ifmmode^\circ\else\textdegree\fi{}K) of the diamagnetic susceptibility of zinc and cadmium single crystals and several polycrystalline gamma-brasses has been investigated. For zinc, pronounced maxima occur in the susceptibility parallel to the hexagonal axis (${\ensuremath{\chi}}_{\ensuremath{\parallel}}$) at 40\ifmmode^\circ\else\textdegree\fi{}K and 105\ifmmode^\circ\else\textdegree\fi{}K, and minima occur at 60\ifmmode^\circ\else\textdegree\fi{}K and 180\ifmmode^\circ\else\textdegree\fi{}K. The susceptibility perpendicular to the hexagonal axis (${\ensuremath{\chi}}_{\ensuremath{\perp}}$) is independent of temperature from 14\ifmmode^\circ\else\textdegree\fi{}K to 100\ifmmode^\circ\else\textdegree\fi{}K and then decreases linearly as the temperature is increased. For cadmium, ${\ensuremath{\chi}}_{\ensuremath{\parallel}}$ decreases by a factor of three between 14\ifmmode^\circ\else\textdegree\fi{}K and 373\ifmmode^\circ\else\textdegree\fi{}K while ${\ensuremath{\chi}}_{\ensuremath{\perp}}$ increases by 7 percent in the same temperature interval. Measurements on polycrystals of copper-zinc alloys in the gamma-phase show that the temperature coefficient of susceptibility changes from positive to negative as copper content is increased, in agreement with previously reported measurements above room temperature. At the copper rich end of the phase, the susceptibility increases by 10 percent between 14\ifmmode^\circ\else\textdegree\fi{}K and 293\ifmmode^\circ\else\textdegree\fi{}K; at the zinc rich end of the phase, the susceptibility decreases by 3 percent in the same temperature interval.