Fabrication of lattice-tunable Ea_(1-x)Sr)xTiO_3 buffers on a SrTiO_3 substrate

摘要

Solid state combinatorial synthesis of oxide thin films is an attractive proposition due to the large number of compositions that could have potentially useful properties. Thin film growth, however, presents a unique set of problems related to the formation of heterointerfaces. Although this problem affects mostly the study of heterostructures, even simple film growth has to handle the substrate-film interface. We have developed a technique for growing lattice constant tunable Ba_(1-x)Sr_xTiO_3 (BSTO)/BaTiO_3 (BTO) buffer layers on SrTiO_3 (STO) substrates in order to study the effects of lattice strain in a systematic way in combinatorial thin film libraries. We show that by combining low temperature deposition and high temperature annealing, it is possible to grow buffers with an in-plane lattice constant gradient in the range of 3.9-4.02 A using a composition spread Ba_(1-x)Sr_xTiO_3 layer.