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

• 作者: Andrey Shumilin Benedicte Warot-Fonrose Ekaterine Chikoidze Elena Popova Niels Keller Veniamin Kozub Yves Dumont
• 来源期刊: 凝固态物理国际期刊(英文)
• 学科: 化学
• 关键词: PACS Numbers: 73.50.-h. TRANSPORT Processes in THIN FILMS 72.20.Ee Hopping TRANSPORT 75.47.Lx MAGNETIC Oxides 75.70.Ak MAGNETIC Properties of Monolayers and THIN FILMS
• 年，卷（期）: 2014,（4）
• 页码范围: 250-261
• 页数: 12页
• 分类号: O6

摘要

Electronic transport properties of magnetically disordered R(-3)c phase Fe1.5Ti0.5O3-δ thin films epitaxially grown on Al2O3(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 0.1μB/formula compared to the theoretical value of 2μB/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 ξ0= 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.