title: Spin polarization in half-metals probed by femtosecond spin excitation.
abstract: Knowledge of the spin polarization is of fundamental importance for the use of a material in spintronics applications. Here, we used femtosecond optical excitation of half-metals to distinguish between half-metallic and metallic properties. Because the direct energy transfer by Elliot-Yafet scattering is blocked in a half-metal, the demagnetization time is a measure for the degree of half-metallicity. We propose that this characteristic enables us vice versa to establish a novel and fast characterization tool for this highly important material class used in spin-electronic devices. The technique has been applied to a variety of materials where the spin polarization at the Fermi level ranges from 45 to 98%: Ni, Co(2)MnSi, Fe(3)O(4), La(0.66)Sr(0.33)MnO(3) and CrO(2).
authors.affiliation: IV. Phys. Institut, Universität Göttingen, D-37077 Göttingen, Germany.
authors.forename: Georg M
authors.initials: GM
authors.lastname: Müller
authors.forename: Jakob
authors.initials: J
authors.lastname: Walowski
authors.forename: Marija
authors.initials: M
authors.lastname: Djordjevic
authors.forename: Gou-Xing
authors.initials: GX
authors.lastname: Miao
authors.forename: Arunava
authors.initials: A
authors.lastname: Gupta
authors.forename: Ana V
authors.initials: AV
authors.lastname: Ramos
authors.forename: Kai
authors.initials: K
authors.lastname: Gehrke
authors.forename: Vasily
authors.initials: V
authors.lastname: Moshnyaga
authors.forename: Konrad
authors.initials: K
authors.lastname: Samwer
authors.forename: Jan
authors.initials: J
authors.lastname: Schmalhorst
authors.forename: Andy
authors.initials: A
authors.lastname: Thomas
authors.forename: Andreas
authors.initials: A
authors.lastname: Hütten
authors.forename: Günter
authors.initials: G
authors.lastname: Reiss
authors.forename: Jagadeesh S
authors.initials: JS
authors.lastname: Moodera
authors.forename: Markus
authors.initials: M
authors.lastname: Münzenberg