Electronic and magnetic structure of RScO_3 (R = Sm,Gd,Dy) from x-ray spectroscopies and first-principles calculations

摘要

The electronic structures of SmScO_3, GdScO_3 and DyScO_3 are investigated by means of x-ray photoelec-tron spectroscopy, x-ray emission spectroscopy (XES), and x-ray absorption spectroscopy (XAS). A strong hybridization between Sc 3d and O 2p is found, and a contribution of the rare-earth 5d states to this hybridization is not excluded. The band gaps of the compounds are determined by combining XES and XAS measurements. For SmScO_3. GdScO_3, and DyScO_3 the band gaps were determined to be 5.6. 5.8, and 5.9 eV, respectively. Magnetization versus temperature measurements reveal antiferromagnetic coupling at 2.96 (SmScO_3), 2.61 (GdScO_3), and 3.10 K (DyScO_3). For DyScO_3 a Rietveld refinement of a 2 K neutron-diffraction data set gives the spin arrangement of Dy in the Pbnm structure (Shubnikov group: Pb'n'm').