TUNNELING STUDY OF INHOMOGENEOUS SB FILMS

Electron tunneling experiments have been performed to study the one-pa rticle density of states in inhomogeneous Sb films. A zero bias anomal y can be well described in terms of the theory of weakly disordered me tals. On the other hand, the background conductance at higher voltages exhibits roughly a parabolic shape, which is typical in a metal-oxide -metal tunnel junction. The feature of the band structure in the semim etal disappears completely. This result indicates that an inhomogeneou s Sb film constitutes a metallic, degenerate electron gas system at th e junction interface. A metastable metallic phase may be stabilized du e to a higher disorder. (C) 1997 Elsevier Science Ltd.