BREAK JUNCTIONS OF THE HEAVY-FERMION SUPERCONDUCTOR UNI2AL3

Mechanical-controllable break junctions of the heavy-fermion supercond uctors can show Josephson-like superconducting anomalies. But a system atic study on the contact size demonstrates that these anomalies are m ainly due to Maxwell's resistance being suppressed in the superconduct ing heavy-fermion phase. Up to day, we could not find any superconduct ing features by vacuum-tunnelling spectroscopy, providing further evid ence for the pair-breaking effect of the heavy-fermion interfaces.