High-spin polarized Co-doped (La,Sr)TiO3 thin films on high-mobility SrTiO3 substrates

Abstract We report on the magnetotransport properties and spin polarization of Co-doped (La,Sr)TiO 3 (Co-LSTO) thin films in which the host oxide is a strongly correlated metal with a high density of carriers. In order to probe the spin polarization, we have performed tunneling magnetoresistance (TMR) measurements on magnetic tunnel junctions associating Co-LSTO and Co electrodes. A large spin polarization of around −80% has been determined at low temperatures, indicating that the carriers in this system are highly spin-polarized. We also report on the planar magnetotransport experiments on Co-LSTO films grown on SrTiO 3 substrates. The electrical properties of these samples are strongly dependent on the growth conditions and large electronic mobilities as high as 10 4  cm 2 /V s at T 3 substrate with oxygen vacancies.