PREFERRED DOMAIN ORIENTATION AND MICROSTRUCTURAL DEFECTS IN ERZN

Magnetostriction measurements, performed on a crystal of ErZn, show that in this crystal the domain magnetization is unequally distributed among the six equivalent 〈100〉 easy directions. Metallography reveals the presence of plate-like precipitates on two sots of {100} planes aligned almost exclusively along one of the 〈100〉 directions. It is concluded that the domains form preferentially with their planes parallel to the precipitate planes. A consequence of this domain structure, coupled with the large spontaneous magnetostriction, is that the crystal is macro- scopically tetragonal. The thermal expansion is, therefore, anisotropic and the measured anisotropy is quantitatively in perfect accord with the domain distribution deduced from the magnetostriction measurements. © 1979 Taylor & Francis Ltd.