Metallic LaTiO₃/ SrTiO₃Superlattice Films on the SrTiO₃(100) Surface

Abstract

Metallic epitaxial LaTiO 3 /SrTiO 3 superlattice films were fabricated on SrTiO 3 (100) substrates. The superlattice structure maintained compressive epitaxial strain on LaTiO 3 and stabilized the perovskite LaTiO 3 crystal phase, which is not thermodynamically stable in thick films on SrTiO 3 . The superlattice films had very smooth surfaces and grew coherently on the substrates. The lowest resistivity was obtained in a (LaTiO 3 ) 2 /(SrTiO 3 ) 3 superlattice film, reaching 200 µΩ·cm at 300 K. These superlattice films can be applied as epitaxial electrodes in n-type SrTiO 3 epitaxial hetero-devices such as field-effect transistors.