Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 58: Poster Session Transport & Matter at Low Temperature

TT 58.15: Poster

Donnerstag, 14. März 2013, 15:00–19:00, Poster D

Anomalous Hall effect in Mn₅Si₃ and Mn₅Si₃C_0.8 films — Patrick Winkel¹, •Christoph Sürgers¹, Gerda Fischer¹, Inga A. Fischer², and Hilbert v. Löhneysen^1,3 — ¹Physikalisches Institut, KIT, Karlsruhe — ²Institut für Halbleitertechnik, Universität Stuttgart — ³Institut für Festkörperphysik, KIT, Karlsruhe

Antiferromagnetic Mn₅Si₃ (T_N = 100 K) can be tuned ferromagnetically by incorporation of carbon [1]. The highest Curie temperature is observed for Mn₅Si₃C_0.8 with T_C = 350 K. We investigate the magnetoresistance and Hall effect of 45-nm thick films for temperatures T = 2 − 400 K and magnetic fields up to 8 T. For each temperature, the different contributions to the Hall conductivity, σ_xy⁰ and σ_xy^AH, arising from the ordinary and anomalous Hall effect, respectively, are separated by taking into account the temperature dependence of the magnetoresistance and magnetization M.

For ferromagnetic Mn₅Si₃C_0.8, we find a positive ordinary Hall coefficient and a linear behaviour σ_xy^AH ∝ M similar to the isotructural ferromagnet Mn₅Ge₃ [2]. In contrast, a negative ordinary Hall coefficient and a nonlinear behaviour of σ_xy^AH(M) is observed for antiferromagnetic Mn₅Si₃. While the negative σ_xy⁰ is attributed to the change of the electronic structure induced by carbon [3] the nonlinear σ_xy^AH(M) awaits theoretical calculations of the anomalous Hall effect in antiferromagnetic compounds.
[1] C. Sürgers et al., Appl. Phys. Lett. 93, 062503 (2008)
C. Zeng et al., Phys. Rev. Lett. 96, 037204 (2006)
I. Slipukhina et al., Appl. Phys. Lett. 94, 192505 (2009)