Effect of Hydrostatic Pressure and Temperature on the Magnetic Properties of a Nickel-Zinc Ferrite

Abstract

Magnetic properties of a nickel‐zinc ferrite (15% NiO, 35% ZnO, 50% Fe₂O₃) were measured over a temperature range of 23°C to 110°C at hydrostatic pressures up to 40 000 psi. The relation between the shift in Curie temperature, ΔT_c, and the change in pressure, Δp, was empirically found to be $${\mathrm{\Delta T}}_c{\text{=0.078(Δp)}}^{\text{0.316}}$$ . It is shown that if magnetic anisotropy and internal strains limit the magnetizing processes, the relation between coercive force, H_c, maximum flux density, B_m, and initial permeability, μ₀, is given by $$H_c{\mathrm{=\delta B}}_m{\mathrm{/\mu }}_0$$ , where δ is a proportionality constant. The experimental results obtained over the entire range of temperature and pressure verify the above relation. The value of δ is 2.56 for the ferrite investigated.