REBCO superconductor on Ni-NdBCO buffered MgO substrate by liquid phase epitaxy process (RE = Nd, Sm, Y)

Using liquid phase epitaxy (LPE) process, REBa2Cu3Oz/NdBa2(Cu0.77Ni0.23)(3) O-z double layers were grown (REBCO/Ni-NdBCO, RE = Y, Sm, Nd). There is no substantial Ni interaction between REBCO and Ni-NdBCO LPE thick films evide nt from T-c value of over 90 K obtained from multilayer samples when RE = Y and Sm. However, due to a high Ni diffusion coefficient and a high T-c, re duction rate with the Ni substitution, NdBCO/NdBa2(Cu-0.77/Ni-0.23)(3)O-z, multilayers has a low T-c value of 62 K. The Ni diffusion coefficients for different RE123 systems and its relation with temperature were deduced on t he basis of the experimental data and a time-dependent equation. (C) 2001 E lsevier Science B.V. All rights reserved.