Temperature and field dependence of the energy gap of (formula presented) planar junctions

We have constructed (formula presented) planar junctions for both temperature and field dependence studies. Our results show that the small gap is a true bulk property of (formula presented) superconductor, not due to surface effects. The temperature dependence of the energy gap manifests a nearly BCS-like behavior. Analysis of the effect of magnetic field on junctions suggests that the energy gap of (formula presented) depends nonlinearly on the magnetic field. Moreover, (formula presented) has an upper critical field of 15 T, in agreement with some reported (formula presented) from transport measurements.