Experimental and ab initio investigations of the x-ray absorption near edge structure of orthorhombic LuMnO3

X-ray near edge absorption spectroscopy was used to probe the electronic structure of multiferroic orthorhombic LuMnO3 polycrystalline samples and strained, twin-free orthorhombic (1-10) LuMnO3 films grown by pulsed laser deposition on (1-10) YAlO3 substrates. For all o-LuMnO3 samples x-ray near edge absorption spectroscopy spectra reveal that the pre-edge structure is influenced by the increase in MnO6 distortion as a result of the smaller Re-ion or film strain. Furthermore there is clear evidence of anisotropic Mn-O bonding and Mn orbital ordering along the c-and [110] direction. The experimental film and bulk data are in agreement with ab initio simulations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729002]