CI.The structure and magnetic properties of the alloyMn3AlC

Abstract

An alloy of composition close to Mn₃AlC was prepared by induction melting. In the as-cast state the alloy was feebly magnetic at room temperature and the magnetic property was retained after homogenization at 1000°c. This alloy was composed of a single phase possessing an ordered face centred cubic structure with lattice parameter 3·869 å. The ordered structure is similar to that found in the alloy Mn₃ZnC, the properties of which have been described elsewhere. The alloy Mn₃AlC, is strongly magnetic at low temperatures having a saturation moment at 0°k of 99·6 ergs/g/oersted equivalent to a Bohr magneton number 1·20 per Mn atom, the Curie temperature being 15°c. The paramagnetic susceptibility measured over the temperature range 65–800°c, was found to vary with temperature in a manner different from a normal ferromagnetic material, the 1/X-T graph possessing pronounced curvature concave to the temperature axis.