Magnetostriction of Paramagnetic Transition Metals and Alloys

Abstract

Measurements of the longitudinal magnetostriction of transition metals and alloys in groups IV, V, VI, and VIII are reported. With the assumption that the magnetostriction is isotropic the volume-dependence of the magnetic susceptibility is evaluated. A theoretical estimate of the volume-dependence of the orbital susceptibility, ∂ lnχorb/∂ lnV≃1.5 (≃ electronic Gruneisen parameter), agrees well with the measured values for the group V metals. The group IV and VI metals appear to have a linear magnetostriction, though the field-independent susceptibility of a paramagnetic metal would indicate a quadratic magnetostriction as observed in the group V and VIII metals. The negative magnetostriction of Pd, Pt, and their alloys indicates that the exchange interaction decreases with increasing volume. But it is not possible to estimate theoretically the magnetostriction of these and other group VIII metals and alloys since too many unknown factors are involved. The emiprical relation between susceptibility and electron density also fails to predict correctly the magnetostriction.