Rare earth contributions to the X-ray magnetic circular dichroism at the Co K edge in rare earth-cobalt compounds investigated by multiple-scattering calculations

TL;DR

This study uses multiple-scattering calculations to analyze the influence of rare earth elements on the Co K edge XMCD spectra in rare earth-cobalt compounds, revealing the significant role of Tb $d$ states.

Contribution

It provides a detailed theoretical analysis of the XMCD spectra in rare earth-cobalt compounds, highlighting the impact of rare earth $d$ states and enabling separation of local and neighboring atom effects.

Findings

XMCD spectra are highly sensitive to the magnetic environment.

The calculations accurately reproduce experimental spectra.

Tb $d$ states significantly influence the XMCD spectrum at the Co K edge.

Abstract

The X-ray magnetic circular dichroism (XMCD) has been measured at the Co K edge in Co-hcp and R-Co compounds (R=La, Tb, Dy). The structure of the experimental XMCD spectra in the near-edge region has been observed to be highly sensitive to the magnetic environment of the absorbing site. Calculations of the XMCD have been carried out at the Co K edge in Co metal, LaCo$_5$ and TbCo$_5$ within the multiple-scattering framework including the spin-orbit coupling. In the three systems, the XMCD spectra in the near-edge region are well reproduced. The possibility to separate and quantitatively estimate the local effects from those due to the neighboring atoms in the XMCD cross section makes possible a more physical understanding of the spectra. The present results emphasize the major role played by the $d$ states of the Tb ions in the XMCD spectrum at the Co K edge in the TbCo$_5$ compound.