title: Magnetoresistance Versus Oxygen Deficiency in Epi-stabilized SrRu1 - xFexO3 - δThin Films.
abstract: Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu1 - xFexO3 - δepitaxial thin films (x = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu1 - xFexO3 - δthin films with atomically flat surfaces containing different amounts of oxygen vacancies using pulsed laser deposition. Without an applied magnetic field, the films with x = 0.10 and 0.20 showed a metal-insulator transition, while the x = 0.30 thin film showed insulating behavior over the entire temperature range of 2-300 K. Both Fe doping and the concentration of oxygen vacancies had large effects on the negative MR contributions. For the low Fe doping case of x = 0.10, in which both films exhibited metallic behavior, MR was more prominent in the film with fewer oxygen vacancies or equivalently a more metallic film. For semiconducting films, higher MR was observed for more semiconducting films having more oxygen vacancies. A relatively large negative MR (~36.4%) was observed for the x = 0.30 thin film with a high concentration of oxygen vacancies (δ = 0.12). The obtained results were compared with MR studies for a polycrystal of (Sr1 - xLax)(Ru1 - xFex)O3. These results highlight the crucial role of oxygen stoichiometry in determining the magneto-transport properties in SrRu1 - xFexO3 - δthin films.
authors.affiliation: Department of Physics and Oxide Research Centre, Hankuk University of Foreign Studies, Yongin, 17035, South Korea.
authors.forename: Umasankar
authors.initials: U
authors.lastname: Dash
authors.affiliation: Department of Physics and Oxide Research Centre, Hankuk University of Foreign Studies, Yongin, 17035, South Korea.
authors.forename: Susant Kumar
authors.initials: SK
authors.lastname: Acharya
authors.affiliation: Department of Physics and Oxide Research Centre, Hankuk University of Foreign Studies, Yongin, 17035, South Korea.
authors.forename: Bo Wha
authors.initials: BW
authors.lastname: Lee
authors.affiliation: Department of Physics and Oxide Research Centre, Hankuk University of Foreign Studies, Yongin, 17035, South Korea. cu-jung@hufs.ac.kr.
authors.forename: Chang Uk
authors.initials: CU
authors.lastname: Jung
keywords: Epitaxial thin film; Fe-doped SrRuO3; Magnetoresistance; Oxygen vacancy; Reciprocal space mapping; X-ray diffraction