Magnetism and resistivity due to 3d impurities in zinc and gallium

• Main Author: Camwell, Paul Leonard
• Published: University of Warwick 1974
• Subjects: 530.412; QC Physics
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.450641

The resistivity and susceptibility due to 3d transition metal impurities in dilute alloys of gallium were measured in the liquid state and are compared with other systems. A localised magnetic moment is shown to exist in a Curie-Weiss sense for GaMn and GaCr throughout the measuring temperature range. Phase-shift analysis gives good agreement for both the resistivity results and the impurity spin value obtained from the susceptibility results. The susceptibility of single crystals of ZnCr were measured from 4.2 K to - 400 K for both crystallographic directions and the magnetic moment and θ-values determined. A method is presented whereby the results can be treated in such a manner as to "remove" the De Haas-Van Alphen oscillations from the parallel axis of zinc, enabling the field-free impurity effects to be compared for both axes. This method is shown to be consistent with results obtained from zinc single crystals and allows an estimation of the Dingle temperature to be made. A temperature-dependent anisotropy was observed, the ratio of the perpendicular and parallel increment3l susceptibilities being greater than 1 in the low temperature region and the opposite in the high temperature region, assuming a Curie-Weiss law holds. Simple crystal field theory is presented and shown to be inadequate in explaining the anisotropy results.