Electron tunneling experiments on skutterudite Co1-xFexSb3 semiconductors

Electron tunneling experiments were performed on p-Col(1-x)Fe(x)Sb(3)-Al-ox ide-Al junctions for x = 0 and x = 0.1 at 4.2 K. A U-shaped tunneling condu ctance curve obtained for polycrystalline p-CoSb3 clearly shows an energy-b and gap of similar to 50 meV. For p-Co0.9Fe0.1Sb3 skutterudites, a strong z ero-bias conductance anomaly is observed. This anomaly may be due to a stru ctural disorder arising from defects such as vacancies and interstitial Fe atoms. (C) 2000 American Institute of Physics. [S0003-6951(00)00223-0].