Annealing time, temperature, and field dependence of pinned magnetic moments in the collinear antiferromagnet PdMn

Abstract

Magnetic annealing of the collinear antiferromagnet PdMn with excess Pd produces strongly pinned magnetic moments in the annealing field direction. This behaviour can be understood with the help of the magnetic-field-biased diffusion model. Here, the magnetic field creates an energy difference between the two possible occupations of the antiferromagnetic Mn-sublattices by the Pd-excess atoms. This, mediated by diffusion, leads to an imbalance in the amount of the Pd-excess atoms in these sublattices and, subsequently, to an imbalance in the total magnetization of the sublattices. We investigate this effect's dependence on the annealing field, time, and temperature. The results are then compared to the results of the magnetic-field-biased diffusion model, which gives good agreement.