Distribution of the superconducting gap in an YNi2B2C film studied by   point contact spectroscopy
  The differential resistances $R_d=dV/dI(V)$ of point contacts between a normal metal and a c axis oriented YNi2B2C film ($T_c$ = 15.2K) in the superconducting (SC) state have been investigated. $R_d(V)$ contains clear "gap" features connected with processes of Andreev reflection at the boundary between normal metal and superconductor that allow the determination of the SC gap $\Delta$ and its temperature and magnetic field dependence. A distribution of $\Delta$ from $\Delta_min\approx$ 1.5 meV to $\Delta_max\approx$ 2.4 meV is revealed; however the critical temperature $T_c$ in all cases corresponded to that of the film. The value 2$\Delta_max/k_BT_c\approx$3.66 is close to the BCS value of 3.52, and the temperature dependence $\Delta(T)$ is BCS-like, irrespective of the actual $\Delta$ value. It is supposed that the distribution of $\Delta$ can be attributed to a gap anisotropy or to a multiband nature of the SC state in YNi2B2C, rather than to the presence of nodes in the gap. 
D. L. Bashlakov, Yu. G. Naidyuk, I. K. Yanson, S. C. Wimbush, B.   Holzapfel, G. Fuchs, S.-L. Drechsler