Magnetic anisotropy driven by ligand in 4d transition metal oxide SrRuO3

TL;DR

This study reveals that ligand ions, specifically oxygen in SrRuO3, significantly influence magnetic anisotropy through hybridization with transition metal orbitals, challenging traditional views.

Contribution

It introduces the concept of ligand-driven magnetic anisotropy and demonstrates its role in SrRuO3 using spectroscopic techniques and controlled sample thickness.

Findings

Ligand orbital magnetization determines magnetic anisotropy.

Hybridization between Ru 4d and O orbitals is crucial.

Sample thickness affects Ru 4d state localization.

Abstract

The origin of magnetic anisotropy in magnetic compounds is a longstanding issue in solid state physics and nonmagnetic ligand ions are considered to contribute little to magnetic anisotropy. Here, we introduce the concept of ligand driven magnetic anisotropy in a complex transition-metal oxide. We conducted X ray absorption and X ray magnetic circular dichroism spectroscopies at the Ru and O edges in the 4d ferromagnetic metal SrRuO3. Systematic variation of the sample thickness in the range below 10 nm allowed us to control the localization of Ru 4d t2g states, which affects the magnetic coupling between the Ru and O ions. We found that the orbital magnetization of the ligand induced via hybridization with the Ru 4d orbital determines the magnetic anisotropy in SrRuO3.