SUPERCONDUCTIVITY AT 12-K IN Y-NI-B SYSTEM

Abstract

We have observed a superconducting transition at 12 K in the system Y-Ni-B (nominal composition: YNi4B). Sharp drop in resistivity (it does not go to zero) and a diamagnetic susceptibility below 12 K clearly indicate a superconducting transition. Possibility of a magnetic phase transition at this temperature is ruled out by our specific heat measurements. Superconducting fraction of our samples, as estimated from Meissner effect measurements, is about 2%.