Spin polarization in half-metals probed by femtosecond spin excitation.
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).
Müller
Georg M
GM
IV. Phys. Institut, Universität Göttingen, D-37077 Göttingen, Germany.
Walowski
Jakob
J
Djordjevic
Marija
M
Miao
Gou-Xing
GX
Gupta
Arunava
A
Ramos
Ana V
AV
Gehrke
Kai
K
Moshnyaga
Vasily
V
Samwer
Konrad
K
Schmalhorst
Jan
J
Thomas
Andy
A
Hütten
Andreas
A
Reiss
Günter
G
Moodera
Jagadeesh S
JS
Münzenberg
Markus
M