Growth Characteristics and Orientation Tuning of Superconducting Thin Films of Bi2212 Based on Substrate Orientation

In this paper, Bi2212 superconducting thin films were prepared on LaAlO3(100), LaAlO3(110), and LaAlO3(111) single crystals by the sol-gel method. The growth characteristics of Bi2212 superconducting films under equilibrium conditions were systematically investigated. The phase composition, morphology, orientation, and superconducting transition temperature of Bi2212 films were studied. Under the equilibrium growth conditions, Bi2212 was more easily grown along the epitaxial LaAlO3(100). It was determined by the surface energy of the substrate, and the surface energy determined the nucleation energy level of Bi2212. The orientations of LaAlO3 played a significant role in the regulation of the growth orientation of Bi2212. This work lays the foundation for the device application of Bi2212 thin films prepared by the sol-gel method.