Optimizing SrTiO3 films on textured Ni substrates using chemical solution deposition

Abstract

Chemical solution deposition (CSD) is used to grow high-quality (100)-oriented films of SrTiO3 (STO) on CSD Ba0.2 Ca0.8TiO3(100) (BCT) templates on textured W-doped Ni(100) (Ni:W) tape substrates. The BCT template films form a thin layer or “skin” that bridges its significant porosity. STO films grown at 1000 °C appear optimized for heteroepitaxial orientation, surface coverage, and film smoothness. Both interfaces in the STO(100)/BCT(100)/Ni:W(100) stack demonstrate excellent atomic registry and compositional abruptness. Doping STO with a few atomic percent of Nb reduces oxygen diffusion into the film by an order of magnitude and provides greater protection to the Ni interfacial surface from oxidation during the growth of additional functional oxides requiring relatively higher p(O2) high-temperature processing, such as superconducting YBa2Cu3O7−δ. CSD growth of BCT and STO also planarizes pre-existing grooves in the Ni:W(100) tapes while maintaining a high degree of orientation by forming facets at the interfaces.