Controlled Modifications of HTSC Thin-Film Properties by Tailoring Substrate Surfaces

This chapter introduces the use of substrates for high-temperature superconductor (HTSC) thin-film deposition beyond their usual purpose as chemically inert, lattice-matched support for the films. Substrates are used as functional elements in order to controllably modify the growth mode of YBa₂Cu₃O_7–x thin films in the case of vicinal-cut SrTiO₃ single crystals or to locally modify the surface morphology and film/substrate lattice mismatch in the case of ion implanted SrTiO₃. Furthermore, the use of biaxial epitaxial strain is briefly reviewed for HTSC thin films, and the application of this concept to tailor the properties of perovskite thin films in general is shown.