Metal insulator transition and magnetotransport anomalies in perovskite SrIr0.5Ru0.5O3 thin films

Abstract: We investigated the nature of transport and magnetic properties in SrIr0.5Ru0.5O3, (SIRO) which has characteristics intermediate between a correlated non-Fermi liquid state and an itinerant Fermi liquid state, by growing perovskite thin films on various substrates (SrTiO3 (001), (LaAlO3)0.3(Sr2TaAlO6)0.7 (001) and LaAlO3 (001)). We observed systematic variation of underlying substrate dependent metal-to-insulator transition temperatures at 80 K on SrTiO3, 90 K on (LaAlO3)0.3(Sr2TaAlO6)0.7 and 100 K on LaAlO3) in resistivity. Resistivity in the metallic region follows a T3/2 power law; whereas insulating nature at low T is due to the localization effect. Magnetoresistance (MR) measurement of SIRO on SrTiO3 (001) shows negative MR upto 25 K and positive MR above 25 K, with negative MR proportional to B1/2 and positive MR proportional to B2; consistent with the localized-to-normal transport crossover dynamics. Furthermore, observed spin glass like behavior of SIRO on SrTiO3 (001) in the localized regime, validates the hypothesis that (Anderson) localization favors glassy ordering. These remarkable features provide a promising approach for future applications and of fundamental interest in oxide thin films.