Superconductivity of binary and ternary compounds of Bi

Abstract

Binary and ternary compounds of Bi formed with 3d transition elements Ni, Co, Fe, and Cr have been studied. Resistance behavior at low temperatures shows two superconducting transitions, one between 4 and 5 K and the other at 10.3 K. Resistance data above ${T}_{c}$ up to about 25 K reveal a temperature exponent of 2 for higher ${T}_{c}$ samples and 3 when ${T}_{c}$ is lower. ESR studies seem to indicate an increase in the density of states at ${E}_{F}$. Results are discussed in terms of various models based on the Landau Fermi-liquid theory and the observed data are interpreted in terms of spin-density-fluctuation model.