  We studied the electronic structure of a conventional superconductor, ZrB(12)
using high resolution x-photoemission spectroscopy and single crystalline
samples. Experimental results with different bulk sensitivity reveals boron
deficiency and different valence states of Zr at the surface relative to the
bulk. Signature of a satellite features is observed in the Zr core level
spectra corresponding to the bulk of the material suggesting importance of
electron correlation among the conduction electrons in the bulk while the
surface appears to be uncorrelated. These results provide an insight in
fabricating devices based on such superconductors.
