Tailored surfaces of perovskite oxide substrates for conducted growth of thin films

摘要

Oxide electronics relies on the availability of epitaxial oxide thin films.The extreme flexibility of the chemical composition of ABO3 perovskites and thebroad spectrum of properties they cover, inspire the creativity of scientistsand place perovskites in the lead of functional materials for advancedtechnologies. Moreover, emerging properties are being discovered at interfacesbetween distinct perovskites that could not be anticipated on the basis ofthose of the adjacent epitaxial layers. All dreamed new prospects require theuse of suitable substrates for epitaxial growth. Perovskite single crystals arethe workhorses of this activity and understanding and controlling their surfaceproperties have become critical. In this tutorial review we will chiefly focuson the impact of the morphology and composition of the surface of ABO3perovskite substrates on the growth mechanisms and properties of thin filmsepitaxially grown on them. As SrTiO3 is the most popular substrate, we willmostly concentrate on describing the current understanding and achievements forit. Illustrative examples of other perovskite substrates (LaAlO3, LSAT andDyScO3) will be also included. We will show that distinct chemical terminationscan exist on the surfaces used for growth and we will review methods employedeither to select the most appropriate one for specific growth to allow, forinstance, tailoring the ultimate outmost epilayer, or to induce self-orderingto engineer long-range nanoscale patterns of chemical terminations. We willdemonstrate the capacity of this knowledge by the growth of low-dimensionalorganic and inorganic structures.