Electronic and magnetic transitions in perovskite SrRu1-xIrxO3 thin films

Abstract

We have investigated the electronic and magnetic properties of perovskite SrRu1-xIrxO3 (0.0 <= x <= 0.25) thin films grown by pulsed laser deposition on atomically flat (001) SrTiO3 substrates. SrRuO3 has the properties of a ferromagnetic metal (resistivity rho similar to 200 mu Omega.cm at T = 300 K) with Curie temperature T-C similar to 150 K. Substituting Ir (5d(5+)) for Ru (4d(4+)) in SrRuO3, films (0.0 <= x <= 0.20) showed fully metallic behavior and ferromagnetic ordering, although rho increased and the ferromagnetic T-C decreased. Films with x = 0.25 underwent the metal-to-insulator transition (T-MIT similar to 75 K) in rho, and spin-glass-like ordering (T-SG similar to 45 K) with the elimination of ferromagnetic long-range ordering caused by the electron localization at the substitution sites. In ferromagnetic films (0.0 <= x <= 0.20), rho increased near-linearly with T at T> T-C, but in paramagnetic film (x = 0.25) rho increased as T-3/2 at T>T-MIT. Moreover, observed spin-glass-like (T-SG) ordering with the negative magnetoresistance at T< T-MIT in film with x = 0.25 validates the hypothesis that (Anderson) localization favors glassy ordering at amply disorder limit. These observations provide a promising approach for future applications and of fundamental interest in 4d and 5d mixed perovskites. (C) 2015 AIP Publishing LLC.