4p states and X-Ray Spectroscopy

TL;DR

This paper explores how 4p states in transition metals influence resonant x-ray scattering and magnetic circular dichroism, revealing their sensitivity to neighboring electronic states and lattice distortions.

Contribution

It demonstrates the mechanisms of RXS and MCD at the K-edge involving 4p states through band structure calculations, highlighting their role in orbital and magnetic phenomena.

Findings

4p states are sensitive to neighboring electronic states and lattice distortions.

Orbital RXS signals are mainly due to lattice distortion effects.

Magnetic RXS and MCD share similar mechanisms involving 4p states.

Abstract

The 4p states in transition metals and their compounds usually play minor roles on their physical quantities. Recent development of resonant x-ray scattering (RXS) at the K-edge of transition metals, however, casts light on the 4p states, because the signals on orbital and magnetic superlattice spots are brought about by the modulation in the 4p states. The 4p states are extending in solids and thereby sensitive to electronic states at neighboring sites. This characteristic determines the mechanism of RXS that the intensity on the orbital superlattice spots are mainly generated by the lattice distortion and those on magnetic superlattice spots by the coupling of the 4p states with the orbital polarization in the 3d states at neighboring sites. Taking up typical examples for orbital and magnetic RXS, we demonstrate these mechanisms on the basis of the band structure calculation. Finally, we study the MCD spectra at the K-edge, demonstrating that the same mechanism as the magnetic RXS is working.