Possible Superconducting Effect at Interface of Ultrathin Silver Layer on Ge(100)2×1

We present semi-superconducting behavior on ultrathin silver layer on clean Ge(100) surface at low temperatures. Films with thickness about 10Å were grown on clean Ge(100)2×1+2×4 substrate at 160 K and subsequently annealed at room temperature in UHV conditions. LEED pattern of annealed sample showed a streaky two domain Ag(110). From LEED and AES data we conclude growth is Stranski-Krastanov with Ag islands elongated along Ge[011] or Ge[0 /line{1}1]. After air exposure these samples showed a maximum in their electrical resistance at about 8 K and a minimum around 5 K. The current and magnetic field dependence of resistance in this temperature region is consistent with an incomplete superconductivity transition. We evaluate some models to explain our experimental data.