Band-Structure Effects in the High-Field Magnetization of Pd and Dilute Pd–Rh and Pd–Ag Alloys

Abstract

From Stoner theory we show that the magnetic field‐vs‐spin magnetization has the form B(σ)=σ/χ(0)+ΔB(σ). The low‐field susceptibility χ(0) is exchange‐enhanced but, if the effective exchange potential does not depend on magnetization, the deviation from linearity ΔB may be derived solely from the band density of states N(E). The previously reported Pd band‐structure calculations, which were in excellent agreement with the de Haas‐van Alphen data, have been extended to yield ΔB(σ) for Pd and, using the rigid band model, also for dilute Pd–Rh and Pd–Ag alloys. A van Hove singularity near the Fermi level of the 7% Rh–Pd alloy has a profound effect on ΔB. Our results are consistent with the measurements of Foner and McNiff, but detailed comparison is difficult since ΔB is of the same order as the experimental uncertainty; moreover, the experimental data have previously been analyzed according to a power series expansion of σ(B) that neither separates the effect of band structure from that of exchange enhancement nor applies when van Hove singularities are important. Our formulation suggests a way of analyzing the experimental data.