YBa 2Cu 3O 7− δ deposition on Ni–Cr alloy tape by liquid phase epitaxy method

Abstract

Thick YBa 2Cu 3O 7− δ (YBCO) films have been successfully formed by the liquid phase epitaxy (LPE) method on Ni–Cr alloy tape. A buffer layer of yttria stabilized zirconia and seed layer of YBCO were formed by the ion beam assisted deposition and by the pulsed laser deposition method, respectively. YBCO films have been grown from the solution of BaO–CuO–Ag–BaF 2 at 820, 845 and 860 °C under low oxygen partial pressure of 2% to prevent the metallic substrate from reacting with the solution. Good YBCO films are obtained by the growth at 820 °C, and the best one shows high critical current density of 1.9 MA/cm 2. A cross-sectional observation by high resolution scanning electron microscopy shows neither reaction layer nor damaged region at the substrate/YBCO film interface. θ–2 θ and pole figure X-ray diffraction of the seed layer and the YBCO LPE layer show that in-plane orientation distribution is highly improved by the LPE process.