Hard X-ray photoemission spectroscopy of pyrochlore molybdenum oxides R2Mo2O7 (R=Sm, Tb)

Abstract: We have carried out hard X-ray photoemission spectroscopy (HXPES) for pyrochlore molybdenum oxides Sm2Mo2O7 and Tb2Mo2O7 single crystals with excitation energy of 5.95keV, in order to investigate electronic structures and correlations in the bulk. The Mo 3d core spectra show complex features, in contrast to an ordinary doublet spectral feature derived from the spin–orbit interaction, indicating significant electron correlation in the valence band. While an intense peak structure at ∼0.5eV is observed in the valence band of Sm2Mo2O7, the peak is broadened and shifted way in Tb2Mo2O7, which suggests the difference of the electron correlation energy depending on the rare-earth site. [Copyright &y& Elsevier]