Optical transitions in non-stoichiometric LaMnO3 identifying the charge-transfer transitions

Using the Mott–Littleton approach we examine the energies of a number of fundamental optical transitions, as well as those involving self-trapped holes of Mn and O in LaMnO3 lattice. The reasonable agreement with the experiment of our predicted energies, linewidths and oscillator strengths leads us to plausible assignments of the optical bands observed. We deduce that the optical band near 5 eV is associated with O(2p)–Mn(3d) transition of chargetransfer character, whereas the band near 2:3 eV is rather associated with the presence of Mn and/or O self-trapped holes in the as-grown non-stoichiometric LaMnO3 compound. We do not exclude other contributions to the latter band. r 2002 Elsevier Science B.V. All rights reserved.