Temperature-dependent X-ray absorption near edge spectroscopy of doped LaMnO3: Ion-size and the Jahn-Teller distortion effects

Abstract

The temperature-dependent X-ray absorption near-edge spectroscopy (XANES) of LaMnO3 thin films doped with various divalent ions was systematically carried out to investigate the effects of the ion size and associated Jahn-Teller distortions (JTDs) on the electronic structure modifications. Doped LaMnO3 thin films were grown on (100) SrTiO3 and (110) NdGaO3 substrates by pulsed-laser deposition with typical thickness of 250-300 nm. Temperature-dependent resistivity p(T) and magnetization M(T) were measured. The results indicate that the drastic changes in magneto-transport properties induced by the substitution of A-site ion and the splitting of the O K-edge pre-edge peak associated with the e(g)(up arrow) and t(2g)(down arrow) energy levels at low temperatures in La1-xCaxMnO3 and La1-xSrxMnO3 (x = 0.3, 0.375) may both relate to the lattice disorder and the associated JTD effects on modifying the electronic structure of doped-LaMnO3. (C) 2009 Elsevier B.V. All rights reserved.