A Search for New Superconducting Compounds

Abstract

In an effort to throw new light on the electronic and structural conditions necessary for superconducting behavior, a magnetic test for superconductivity was applied to about ninety binary and ternary compounds at temperatures down to 1.28\ifmmode^\circ\else\textdegree\fi{}K. The new superconductors ${\mathrm{Mo}}_{2}$N, MoN, ${\mathrm{Mo}}_{2}$B, NbB, Sr${\mathrm{Bi}}_{3}$, and Ba${\mathrm{Bi}}_{3}$ were discovered, and the superconductivity of TiN, ZrN, VN, ${\mathrm{Mo}}_{2}$C, MoC, and ${\mathrm{W}}_{2}$C, reported by previous investigators using the inconclusive electrical resistance test, was confirmed magnetically. No trace of superconductivity was observed in any one of the several ionic, covalent, or semiconducting compounds examined or in nine borides with boron content greater than 50 atomic percent. The results are discussed in relation to crystal structure and the periodic table.