Metal-insulator transitions in epitaxial LaVO3 and LaTiO3 films

We have demonstrated that epitaxial films of LaVO₃ and LaTiO₃ can exhibit metallicity though their bulk counterparts are Mott insulators. When LaTiO₃ films are compressively strained on SrTiO₃ substrates, we observe metallicity that is attributed largely to epitaxial strain-induced electronic structure modifications and secondarily to interface electronic reconstruction at the LaTiO₃/SrTiO₃ interface. However, when LaVO₃ films are compressively strained on SrTiO₃ substrates, the observed metallicity is primarily attributed to interface effects. Signatures of weak localization are observed at low temperature in LaVO₃ films in the temperature, film thickness, as well as magnetic field dependence of the magnetoresistance.