Dependences of High Magnetic Permeability on Crystal Magnetic Anisotropy and Magnetostriction for “Nimalloy” in the Ni–Mn System

Abstract

Measurements of the crystal magnetic anisotropy K1 and the saturation magnetostriction λs were carried out for disk-shaped single crystal specimens with a (001) plane and rod-shaped poly-crystal specimens prepared from Ni–Mn alloys containing less than about 25% manganese. Prior to measurements, all the specimens were heated at high temperatures and then subjected to various heat treatments. The negative values of K1 and λs increased rapidly with increasing manganese content and became positive in compositions near 20% manganese. In compositions below about 20% manganese both values were nearly independent of the kind of heat treatment. These results lead to the conclusion that the high magnetic permeability of Ni–Mn alloys containing about 20% manganese is induced by the low values of K1 and λs.