Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 101: Transport - Poster Session

TT 101.6: Poster

Donnerstag, 3. April 2014, 15:00–19:00, P2

Magnetotransport in ferromagnetic Mn₅Ge₃ and Mn₅Ge₃C_0.8 thin films — •Christoph Sürgers¹, Patrick Winkel¹, Gerda Fischer¹, Inga A. Fischer², and Li-Te Chang³ — ¹Physikalisches Institut, Karlsruhe Institute of Technology, 76049 Karlsruhe — ²Institut für Halbleitertechnik, Universität Stuttgart, 70569 Stuttgart — ³Device Research Lab., Dept. of Electrical Engineering., University of California, Los Angeles, CA 90095, USA

Ferromagnetic Mn₅Ge₃ and Mn₅Ge₃C_0.8 compounds with Curie temperatures of ≈ 300 K and 450 K, respectively, are potential electrode-materials for spin injection into Si and Ge due to their high resistivity and compatibility with CMOS technology [1]. We investigate the temperature dependence of the anisotropic magnetoresistance (AMR) and the anomalous Hall effect of sputtered thin films. The AMR changes sign from negative to positive with increasing temperature with a concomitant increase and sign change of the ordinary Hall coefficient R₀ while the anomalous Hall coefficient is independent of temperature. The correlation between the temperature dependence of R₀ and of the AMR ratio is discussed by considering a change of the different contributions arising from the electron-like minority-spin band and the hole-like majority-spin band to the conductance with increasing temperature. Magnetoresistance measurements in the Hanle geometry on Mn₅Ge₃C_0.8 electrodes deposited on highly doped n-Ge reveal that spin injection and spin extraction occur, however, at temperatures below 15 K.
I. A. Fischer et al., Semicond. Sci. Technol. 28, 125002 (2013)