Tunneling spectroscopy on epitaxial UNi2Al3 thin films

We are presenting the first results of tunneling spectroscopy experiments performed on the heavy fermion superconductor UNi2Al3. Planar junctions consisting of an a*-axis oriented UNi2Al3 thin film as a base electrode, AlOx, insulating layer and a metal counter electrode were prepared employing an in vacuo process. The observation of the well-known superconducting density of states of the counter electrode (Pb) allows the evaluation of the junction quality. Although the junctions are in the tunneling regime, no features which could be associated with the superconducting state of the heavy fermion compound were observed.