DFT Investigation of Magnetocrystalline Anisotropy in Fe, Co, Pd0.97Co0.03 and Pd0.97Fe0.03 systems: From Bulk to Thin-Films

TL;DR

This study uses density functional theory to analyze how magnetocrystalline anisotropy varies in Fe, Co, and Pd-based alloys across different geometries, revealing composition and structural effects on magnetic properties.

Contribution

It provides new insights into the anisotropy behavior of dilute Fe-Co-Pd alloys in bulk and thin-film forms using non-collinear spin-orbit calculations.

Findings

Fe and Co show opposite easy-axis orientations depending on geometry.

3% Co doping in Pd induces anisotropy similar to pure Co.

Fe-Pd alloys remain isotropic in bulk despite doping.

Abstract

The nature of low-impurity ferromagnetism remains a challenging problem in the solid-state community due to the strong dependence of magnetic properties on composition, concentration, and structural geometry of diluted alloys. To address this, we performed a density functional theory study of magnetocrystalline anisotropy in Fe, Co, Pd0.97Co0.03, and Pd0.97Fe0.03 systems across bulk, monolayer, and thin-film geometries. Non-collinear spin-orbit calculations were employed to evaluate the magnetocrystalline anisotropy energies, supported by analysis of atomic-, spin-, and orbital-resolved densities of states. The results revealed that Fe and Co exhibit opposite easy-axis orientation depending on geometry. At the same time, even 3% Co-doping in Pd is sufficient to induce anisotropy trends resembling those of pure Co. In contrast, Fe-Pd system at the same concentration do not reproduce the anisotropy of pure Fe, showing isotropic behavior in bulk.