Electronic structure of Nd1−xYxMnO3 from Mn K edge absorption spectroscopy and DFT methods

•Reduction in the pre-edge intensity of Mn K edge spectrum with doping.•DFT based LMTO calculations are consistent with experimental observations.•Increase in the band gap and decrease in the magnetic moment as seen from experiments.•Signature of orbital ordering seen in density of states of pure compound, not seen in doped compound.•Greater hybridization and delocalization of the Mn 3d–Mn 4p orbitals.

The electronic structure of Nd1−xYxMnO3 (x=0–0.5) is studied using x-ray absorption near-edge structure (XANES) spectroscopy at the Mn K-edge along with the DFT-based LSDA+U and real space cluster calculations. The main edge of the spectra does not show any variation with doping. The pre-edge shows two distinct features which appear well-separated with doping. The intensity of the pre-edge decreases with doping. The theoretical XANES were calculated using real space multiple scattering methods which reproduces the entire experimental spectra at the main edge as well as the pre-edge. Density functional theory calculations are used to obtain the Mn 4p, Mn 3d and O 2p density of states. For x=0, the site-projected density of states at 1.7 eV above Fermi energy shows a singular peak of unoccupied eg (spin-up) states which is hybridized Mn 4p and O 2p states. For x=0.5, this feature develops at a higher energy and is highly delocalized and overlaps with the 3d spin-down states which changes the pre-edge intensity. The Mn 4p DOS for both compositions, show considerable difference between the individual px, py and pz states. For x=0.5, there is a considerable change in the 4p orbital polarization suggesting changes in the Jahn–Teller effect with doping.