Pyrolysis induced surface morphology evolution of YBa2Cu3O7-? films prepared by low-fluorine metal-organic deposition

YBa₂Cu₃O_7-δ films with different surface morphologies in pyrolysis process were prepared by metal-organic deposition (MOD) method. Varied surface morphologies were formed in different heating rates and gas flows in pyrolysis process. Four typical surfaces of pyrolyzed films were cracks, smooth surfaces, wrinkles and both of cracks and wrinkles. Huge volume change which existed in pyrolysis process may cause stress in films. Salts decomposition in precursor solution was the main source of stress therefore smooth surfaces appeared in suitable heating rates and gas flows.