1s2p Resonant Inelastic X-ray Scattering Magnetic Circular Dichroism as a probe for the local and non-local orbitals in CrO2

作者：Zimmermann Patric; Bouldi Nadejda; Hunault Myrtille O J Y; Sikora Marcin; Ablett James M; Rueff Jean Pascal; Lebert Blair; Sainctavit Philippe; de Groot Frank M F^*; Juhin Amelie

来源：Journal of Electron Spectroscopy and Related Phenomena, 2018, 222: 74-87.

DOI：10.1016/j.elspec.2017.08.004

• RIXS-MCD
• Magnetic circular dichroism
• Non-local
• 4p3d hybridisation
• CrO2
• Distortion

We have determined the magnetic ground state of the half-metal CrO2 based on 1s2p Resonant Inelastic X-ray Scattering Magnetic Circular Dichroism (RIXS-MCD) experiments. The two-dimensional RIXS-MCD map displays the is X-ray absorption spectrum combined with the 1s2p X-ray emission decay, where there is a large MCD contrast in the final state involving the 2p core hole.
Our measurements show that the Cr K pre-edge structure is dominated by dipolar contributions and the quadrupole peak is invisible in direct K pre-edge absorption. Using RIXS-MCD, we reveal that the quadrupole 1s3d pre-edge has a large MCD contrast, which appears at lower energy with respect to the K pre-edge maximum.
We use crystal field multiplet calculations to model the excitonic RIXS-MCD spectral shape in tetragonal (D-4h) symmetry. The RIXS-MCD is strongly sensitive to the ground state distortion of the Cr4+ sites. The calculations of the RIXS-MCD maps suggest that the 3d spin orbit interaction is fully quenched (zeta(3d)= 0 meV) and the ground state electron configuration must contain a B-3(2g) (D-4h) contribution, which is required to explain the appearance of the Magnetic Circular Dichroism (MCD) in the Cr K pre-edge. This is in apparent contrast with the compressed tetragonal distortion.

• 出版日期2018-1