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

From Stoner theory we show that the magnetic field-vs-spin magnetization has the form B(sigma)=sigma/chi(0)+DeltaB(sigma). The low-field susceptibility chi(0) is exchange-enhanced but, if the effective exchange potential does not depend on magnetization, the deviation from linearity DeltaB 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 DeltaB(sigma) for Pd and, using the rigid band model, also for dilute Pd[Single Bond]Rh and Pd[Single Bond]Ag alloys. A van Hove singularity near the Fermi level of the 7% Rh[Single Bond]Pd alloy has a profound effect on DeltaB. Our results are consistent with the measurements of Foner and McNiff, but detailed comparison is difficult since DeltaB is of the same order as the experimental uncertainty; moreover, the experimental data have previously been analyzed according to a power series expansion of sigma(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. ©1970 The American Institute of Physics