title: Half-metallic ferromagnetism with unexpectedly small spin splitting in the Heusler compound Co2FeSi.
abstract: Half-metallic ferromagnetism stands for the technologically sought-after metallicity with 100% spin polarization. Electrical transport should, in principle, sensitively probe half-metallic ferromagnetism, since electron-magnon scattering processes are expected to be absent, with clear-cut consequences for the resistivity and the magnetoresistance. Here we present electrical transport data for single-crystalline Co(2)FeSi, a candidate half-metallic ferromagnet Heusler compound. The data reveal a textbooklike exponential suppression of the electron-magnon scattering rate with decreasing temperature which provides strong evidence that this material indeed possesses perfect spin polarization at low temperature. However, the energy scale for thermally activated spin-flip scattering is relatively low (activation gap Δ≈100 K) which has decisive influence on the magnetoresistance and the anomalous Hall effect, which exhibit strong qualitative changes when crossing T≈100 K.
authors: IFW Dresden, 01171 Dresden, Germany. d.bombor@ifw-dresden.de
authors: Dirk
authors: D
authors: Bombor
authors: Christian G F
authors: CG
authors: Blum
authors: Oleg
authors: O
authors: Volkonskiy
authors: Steven
authors: S
authors: Rodan
authors: Sabine
authors: S
authors: Wurmehl
authors: Christian
authors: C
authors: Hess
authors: Bernd
authors: B
authors: Büchner