Metallicity in LaTiO3 thin films induced by lattice deformation

Abstract

Orthorhombic bulk LaTiO3 is a correlated Mott insulator whose delicate antiferromagnetic insulating ground state can be easily destroyed by cation vacancies, excess oxygen, or alkaline-earth dopants, resulting in metallicity. Here we show that metallic conduction can also be realized in epitaxial LaTiO3 thin films on (001) SrTiO3 substrates, while films grown on (110) DyScO3 and GdScO3 substrates are insulating. These results illustrate the sensitivity of electrical transport to lattice effects and demonstrate the tunability of correlated oxide thin-film properties via substrate-induced deformation.