X-RAY SPECTROSCOPY OF LANTHANUM MANGANITES: NATURE OF DOPING HOLES, CORRELATION EFFECTS, AND ORBITAL ORDERING

Abstract

The Mn3s X-ray photoelectron spectra of manganites were studied. It was shown that for the formal valence of manganese from 3+ to 3.3+, the doping holes are O2p in character; as the valence of manganese increases further, the Mn3d states acquire holes. For La0.7Sr0.3MnO3, the Mn3p-3d resonance spectra provided information about the occupied and unoccupied Mn3d states, and the correlation energy U = 6.7 eV was determined experimentally. An analysis of X-ray dichroism on the L absorption spectra of three-dimensional La7/8Sr1/8MnO3 showed that the cooperative Jahn-Teller distortion of the orthorhombic phase at 240 K was related to (x(2) - z(2))/(y(2) - z(2)) type orbital ordering.