Valence, hybridization of electronic states and magnetic properties of La0.7Ca0.3Mn1-xScxO3 (x = 0.0; 0.03, and 0.05) manganites

Abstract

X-ray absorption spectroscopy at Mn K- and L-edges, and at O K-edge, combined with the x-ray diffraction and magnetization measurements are performed to study the electron structure of La0.7Ca0.3Mn1-xScxO3 (x = 0.0; 0.03, and 0.05) perovskites. Substitution of manganese by scandium decreases Curie temperature, Tc, and increases lattice parameters because of the different electron configuration and radii of trivalent manganese and scandium ions. The Tc decrease is explained by the change of level of hybridization of O 2p and Mn 3d states. This is manifested by the parallel shift of O K-edge, change of intensity of 2p3/2 and 2p1/2 spectrum lines and TC with x increase. Fourier transform of the EXAFS spectra shows a change of local crystal structure caused by the larger Sc3+ than the Mn3+ ions.