Abstract
Characteristics of superconductivity in Nb–Ti alloys (Nb-41–55 mass%Ti) are studied through electrical resistivity measurements. The superconducting transition temperature Tc and the electron-phonon resistivity at 273 K, ρep (273 K), are obtained with the measurements. From the experimental values of Tc, the electron-phonon coupling parameter λ is determined as a function of concentration. The density of states at Fermi level N(Ef) is estimated by using the relation between the values of λ obtained here and the coefficient of electronic specific heat γ. The results lead to a conclusion that the increase of Tc is mainly caused by the rise of N(Ef) with concentration. The electron-phonon coupling parameter in electronic transport λtr is also determined from the experimental values of ρep (273 K), and compared with λ.
