Bulk and surface-sensitive high-resolution photoemission study of Mott-Hubbard systems SrVO₃ and CaVO₃

الأصل · EN

We study the electronic structure of Mott-Hubbard systems SrVO₃ and CaVO₃ with bulk and surface-sensitive high-resolution photoemission spectroscopy (PES), using a VUV laser, synchrotron radiation and a discharge lamp (hν = 7 - 21 eV). A systematic suppression of the density of states (DOS) within 0.2 eV of the Fermi level (EF) is found on decreasing photon energy i.e. on increasing bulk sensitivity. The coherent band in SrVO₃ and CaVO₃ is shown to consist of surface and bulk derived features, separated in energy. The stronger distortion on surface of CaVO₃ compared to SrVO₃ leads to higher surface metallicity in the coherent DOS at EF, consistent with recent theory.