Effect of annealing on the superconducting and normal state properties of the doped multifilamentary Cu–Nb composite wires prepared by in situ technique

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 1999-06, Vol.60 (2), p.118-123
• Main Authors: Dubey, S.S, Dheer, P.N, Reddy, Y.S, Krishna, M.M, Sharma, R.G
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effects of crystal defects, doping and substitution; Exact sciences and technology; Metals, alloys and compounds (a15, 001c15, laves phases, chevrel phases, borocarbides, etc.); Metals. Metallurgy; Metals; alloys and binary compounds (including A15, Laves phases, etc.); Physics; Superconducting materials (excluding high-tc compounds); Superconductivity; Transition temperature variations
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/S0921-5107(99)00037-9

The effect of annealing on the superconducting and normal state properties of the Ga-, In-, Ti- and Zr-doped (1 wt%) Cu–Nb composite wires prepared by in situ technique have been investigated in this paper. The wires annealed at 700°C for 10 h and then quenched at room temperature, show a decrease in the superconducting transition temperature, T c, and increase in the transition width, Δ T. Doping of the Cu–Nb wires causes an increase in the normal state resistivity and hence the upper critical field, H C2. This results in a significant increase of J c. Annealing of these doped samples decreases H C2 and J c. In the case of In- and Ga-doped samples J c shows a marginal improvement at lower field but decreases at higher field. Zr and Ti doping appears to be beneficial for the improved J c in these in situ materials.