NEW DATA ON THE ELECTRONIC-STRUCTURE OF LA2CUO4 COMPOUND

The electronic structure of La(1-x)Me(x)CuO(4) compound is studied bot h theoretically and experimentally. The band structure of La2CuO4 crys tal is calculated by relativistic LMTO method. The present work is aim ed to study the electron states of La, particularly the so-called inci pient 4f-states. Our results differ from those obtained previously. Mu ch attention is given to the role of La atom in the formation of the e nergy spectrum of the crystal. We have measured the La M and N X-ray a bsorption and emission spectra to determine the energy location of f-s tates with respect to the Fermi level. To explain the experimental dat a correctly electronic structure of ground and several excited states of [La2Cu4O22] and [LaBaCu4O22] Clusters has been calculated by X(alph a)-scattering wave method. Our density-of-state curves are in good agr eement with the experimental spectra. Our investigations reveal the es sential role of La 4f-states in formation of the energy spectrum near the Fermi level.