The magnetic behaviour of iron impurities in copper and copper-manganese alloys

Abstract

The mossbauer spectra of 1 at.%⁵⁷Fe in copper manganese alloys containing up to 90 at.% manganese have been obtained at 300K and 4.2K, and the ordering temperatures of the hosts found by observing the onset of magnetic splittings in the spectra. The 300K results show a double structure and have been analysed on the basis of a point charge model. However the alloys were, in general, not completely random and clustering of iron and manganese atoms around the iron impurities has been observed. The 4.2K data show that the broad spectra reported previously for copper-iron alloys are due in part to this clustering, and that the magnetic state of the iron atom changes according to the types of nearest neighbour atoms.