Crystal Magnetic Anisotropy Constant and Magnetostriction Dependences of the High Magnetic Permeability for “Nimalloy” in the Ni-Mn-Fe System

Abstract

Crystal magnetic anisotropy constant K₁ and saturation magnetostriction λ_s have been measured on a single crystal disk of the (100) plane and polycrystal rods of Ni-Mn-Fe alloys containing less than about 29%Mn and about 25%Fe which were cooled at a rate of 26°C/sec from 650°C after heating at high temperature. The absolute value of K₁ increases with increasing Fe content and then decreases sligtly after attaining at a maximum. With increasing Mn and Fe contents, the absolute value of λ_s rapidly decreases and then becomes zero at the composition which contains a little larger amount of Ni than Ni₃ (Mn, Fe), after which the value increases gradually. It may be concluded that the high permeability of Ni-Mn-Fe alloys containing about 20%Mn and about 5%Fe is caused by very small values of K₁ and λ_s as in the case of Ni-Mn alloys.