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

Abstract

Metallic epitaxial LaTiO3/SrTiO3 superlattice films were fabricated on SrTiO3 (100) substrates. The superlattice structure maintained compressive epitaxial strain on LaTiO3 and stabilized the perovskite LaTiO3 crystal phase, which is not thermodynamically stable in thick films on SrTiO3. The superlattice films had very smooth surfaces and grew coherently on the substrates. The lowest resistivity was obtained in a (LaTiO3)2/(SrTiO3)3 superlattice film, reaching 200 µΩ·cm at 300 K. These superlattice films can be applied as epitaxial electrodes in n-type SrTiO3 epitaxial hetero-devices such as field-effect transistors.