Effect of Hydrostatic Pressure on the Magnetocrystalline Anisotropy constant K₁ in Si–Fe and Ni

Abstract

Variation of the anisotropy constant K₁ with hydrostatic pressure was determined on 1.08 wt. % Si–Fe and Ni from torque measurements under pressures up to about 5 kbar at 77, 195, 238 and 291 K. The pressure coefficient at absolute zero, (1⁄K₁(0))(ΔK₁(0)⁄Δp), was estimated by extrapolation as −2.1×10⁻⁵ bar⁻¹ for the Si–Fe and −1.4×10⁻⁵ bar⁻¹ for Ni. The temperature dependence of the anisotropy constant at constant volume, K_1V, deduced with (1⁄K₁)(ΔK₁⁄Δp) at all temperature appears to obey the ninth power of the magnetization for the Si–Fe.