Mechanical and critical current characteristics of high-strength (Bi, Pb)2Sr2Ca2Cu3O tapes under uniaxial tensile strain

Abstract

We investigated the mechanical properties and superconducting characteristics of high-strength (Bi, Pb)2Sr2Ca2Cu3O tapes reinforced by Ni-based alloy lamination over a wide range of temperature (30 K≤T ≤ 300 K), magnetic field (), and uniaxial tensile strain (ε ≤ 0.6%) conditions. We found that the Young’s modulus evaluated from the stress–strain curves increases gradually with decreasing temperature (120 GPa at 300 K and 142 GPa at 40 K), indicating the importance of low-T data for designing high-field magnets. The enhancement of the Young’s modulus of the tape at such low temperatures is probably attributable to the use of a Ni-based alloy for reinforcement and is also reflected in the irreversible stress. The critical current, , measured under various (T, B, ε) conditions decreases almost linearly with uniaxial tensile strain in the reversible region. We constructed a phenomenological model of that can roughly reproduce the observed under all the (T, B, ε) conditions we investigated. We expect that fine adjustment of the model parameters based on more detailed measurements will make it possible to estimate under arduous measurement conditions from data obtained under conditions where measurement is relatively easy.