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Schlagwörter:
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Zusammenfassung:
In this work a simple concept was used for a systematic search for
materials with high spin polarization. It is based on two semiempirical
models. First, the Slater-Pauling rule was used for estimation of the
magnetic moment. This model is well supported by electronic structure
calculations. The second model was found particularly for Co-2 based
Heusler compounds when comparing their magnetic properties. It turned
out that these compounds exhibit seemingly a linear dependence of the
Curie temperature as function of the magnetic moment. Stimulated by
these models, Co2FeSi was revisited. The compound was investigated in
detail concerning its geometrical and magnetic structure by means of
x-ray diffraction, x-ray absorption, and Mossbauer spectroscopies as
well as high and low temperature magnetometry. The measurements revealed
that it is, currently, the material with the highest magnetic moment (6
mu(B)) and Curie temperature (1100 K) in the classes of Heusler
compounds as well as half-metallic ferromagnets. The experimental
findings are supported by detailed electronic structure calculations.
