Biaxially textured copper and copper–iron alloy substrates for use inYBa2Cu3O7−x coated conductors

Abstract

Copper and Cu–Fe (Fe ∼2.35 wt%) alloy substrates were thermo-mechanically processed and the biaxial texture development,magnetic properties, yield strength, and electrical resistivity were studied and compared todetermine their suitability as substrates for high-temperature superconductingcoated conductor applications. Average full width half maximum (FWHM) of5.5° in Phi scans (in-planealignment), and 6.6° in omega scans (out-of-plane alignment) was obtained in copper samples. Cu–Fe samples showed5.9° FWHM inPhi scans and 5.9° in omega scans. Even with the presence of 2.35% Fe in the Cu-alloy, the saturation magnetization(Msat) value wasfound to be 4.27 emu g−1 at 5 K, which is less than in Ni samples by an order of magnitude and comparable to that ofNi–9 at.% W substrates. The yield strength of the annealed Cu–Fe alloy substrate was foundto be at least two times higher than that of similarly annealed copper substrates. Theelectrical resistivity of Cu–Fe alloy was found to be an order of magnitude higher than thatof pure copper at 77 K.