Low Temperature Fabrication of REBa_2Cu_3O_y Epitaxial Films on SrTiO_3 (100) Substrate Prepared by Molten Hydroxide Method in 1-atm Air

In order to establish the fabrication method of high-T_c REBa_2Cu_3O_y (RE123) films by feasible simple system, we fabricated the RE123 films on SrTiO_3 substrate by molten hydroxide method in low temperature and 1-atm air. Obtain films of RE-123 (RE = Gd, Eu, Sm) fabricated at low temperature of 525°C show a c-axis orientation of RE123 and REBa_2Cu_4O_8 phases. Moreover, the Nd-123 films show a bi-axial orientation of Nd123 single phase completely above 425°C. The T_c^<onset> of Nd123 film fabricated at 525°C denotes 67.1 K which was drastically lower compared with previous study of Nd123 single crystalline film, and T_c^<onset> of Nd123 films degrade with decreasing fabrication temperature. We can consider that the Nd/Ba substitution was caused by lowering the fabrication temperature.