Large Room Temperature Magneto-Resistance in Magnetically Disordered Fe<sub>1.5</sub>Ti<sub>0.5</sub>O<sub>3-δ</sub> Thin Films — Oak Academic Publishing
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Large Room Temperature Magneto-Resistance in Magnetically Disordered Fe<sub>1.5</sub>Ti<sub>0.5</sub>O<sub>3-δ</sub> Thin Films
Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
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Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
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Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
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Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
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A. F. IoffePhysico-Technical Institute, Russian Academy of Sciences, St. Peterbourg, Russia
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A. F. IoffePhysico-Technical Institute, Russian Academy of Sciences, St. Peterbourg, Russia
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CEMES-CNRS, Toulouse, France
1 Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
2 Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
3 Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
4 Groupe d’Etudes de la Matière Condensée (GEMaC), Université de Versailles St-Quentin en Yvelines—CNRS, Versailles, France
5 A. F. IoffePhysico-Technical Institute, Russian Academy of Sciences, St. Peterbourg, Russia
6 A. F. IoffePhysico-Technical Institute, Russian Academy of Sciences, St. Peterbourg, Russia
Electronic transport properties of magnetically disordered R(-3)c phase Fe 1.5 Ti 0.5 O 3- δ thin films epitaxially grown on Al 2 O 3 (0001) substrates have been studied. The measured magnetization in configurations with the magnetic field perpendicular and parallel to the film plane shows weak values of 0.1 μ B /formula compared to the theoretical value of 2 μ B /formula and a strong anisotropy with no saturation in perpendicular configuration. These properties are associated with the ato- mic scale disorder of Ti/Fe ions along c-axis. At zero-magnetic field and within the temperature range of 80 K to 400 K, the conduction mechanism appears to be Efros-Shklovskii variable range hopping with a carrier localization length of ξ 0 = 0.86nm . Magneto-resistance (MR) is positive in perpendicular configuration, while it is negative in parallel configuration, with significant values of MR = 27%- 37% at room temperature at 9 Tesla. Electron localization lengths were deduced from experiment for different external magnetic fields. The origin of magneto-resistance observed in experiment, is discussed.
KeywordsPACS Numbers: 73.50.-h. Transport Processes in Thin Films72.20.Ee Hopping Transport75.47.Lx Magnetic Oxides75.70.Ak Magnetic Properties of Monolayers and Thin Films
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