Liquid phase epitaxy of crystalline REBa2Cu3O6+delta films on reactive substrates using the BaF2-BaO-CuO flux

Phase relations concerning the crystal formation of YBa2Cu3O6+delta and NdBa2Cu3O6+delta phases from the BaF2-BaO-CuO flux have been investigated by the liquid phase epitaxial technique on various substrates. As the amount of BaF2 in the solution increases, the temperature of REBa2Cu3O6+delta (RE = Y, Nd) formation decreases down to about 920 degrees C not only in the Y system but also in the Nd system. The decrease of the growth temperature allows us to form liquid phase epitaxial thick films on the reactive substrates such as yttria-stabilized zirconia and SrTiO3, which rapidly react with REBa2Cu3O6+delta and the melt of barium cuprate flux at high temperatures. Our studies have also revealed that the seed layer pre-deposited on the substrates plays an important role in epitaxial growth of REBa2Cu3O6+delta to form thick films on these substrates. (C) 1997 Elsevier Science B.V.