Electronic structures of Mo pyrochlore: R2Mo2O7 (R=Nd, sm)

Abstract

The electronic structures of Mo pyrochlore systems of R2Mo2O7 (R=Nd, Sm) have been investigated using photoemission spectroscopy (PES). The electronic states near E-F have mainly Mo 4d character. The R 4f states are located well below the Fermi level and the valence states of bulk Nd and Sm ions are very close to 3+. The local spin density approximation (LSDA) and LSDA+U+spin-orbit (SO) band calculations incorporating the effects of the on-site Coulomb correlation U and the SO interaction of Nd 4f electrons show the large hybridization between the Mo 4d and O 2p orbitals and the magnetic moment of similar to1.0mu(B) per Mo atom. The qualitative features of the measured valence-band PES spectra of Nd2Mo2O7 agree well with the LSDA+U+SO band structure calculation. The origin of the stable ferromagnetic phase in Nd2Mo2O7 has been discussed based on the nearly half-metallic electronic structure.