Effects of seed layer on YBa2Cu3Ox films grown by liquid phase epitaxy

Crack-free YBa2Cu3Ox, (YBCO) films were grown by liquid phase epitaxy (LPE) on MgO(100) substrates with a YBCO seed layer. The crystalline property of LPE was crucially dependent on that of the seed layer. On the purely c-axi s-oriented seed layer, reasonable YBCO films were grown with a full-width a t half maximum of the (005) reflection rocking curve: aw, of 0.07 degrees. In the case of the seed including an a-axis-oriented grain, the value of ao of LPE films was poor in reproducibilily and larger than 0.1 degrees on av erage. For the a-axis-oriented seed, no YBCO films grew under the growth co nditions in this study. X-ray topographic observations revealed that the cr ystalline quality of MgO substrates limited the aw of LPE films grown on th em.