Discovery and properties of quaternary borocarbide superconductors

The discovery of superconductivity in Y-Ni-B-C by Indian scientists has led to a new class of materials, viz, Quaternary Rare Earth Borocarbides, with many interesting properties. Several members of the series show superconductivity with high T-c for intermetallics with the multiphase Y-Pd-B-C system showing a T-c of 23K which is highest for bulk intermetallics. Some of the magnetic mem hers of the family exhibit the exotic phenomenon of coexistence of superconductivity with high T-c as well as high magnetic ordering temperatures. The two cooperative phenomena occurring at comparable energy scale results in new aspects of interplay of magnetism and superconductivity. In quaternaries, there is ample scope for finding new materials possibly with even higher T(c)s and newer phenomena. A glimpse of this new and exciting field is presented here