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High spin polarization in the ferromagnetic filled skutterudites KFe4Sb12 and NaFe4Sb12

Goutam Sheet·H. Rosner·S. Wirth·A. Leithe-Jasper·W. Schnelle·U. Burkhardt·J. A. Mydosh·P. Raychaudhuri·Yu. Grin
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Abstract

The spin polarization of ferromagnetic alkali-metal iron antimonides KFe4Sb12 and NaFe4Sb12 is studied by point-contact Andreev reflection using superconducting Nb and Pb tips. From these measurements an intrinsic transport spin polarization Pt of 67% and 60% for the K and Na compound, respectively, is inferred which establishes these materials as a new class of highly spin polarized ferromagnets. The results are in accord with band structure calculations within the local spin density approximation (LSDA) that predict nearly 100% spin polarization in the density of states. We discuss the impact of calculated Fermi velocities and spin fluctuations on Pt.

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Goutam Sheet, H. Rosner, S. Wirth, A. Leithe-Jasper, W. Schnelle, U. Burkhardt, J. A. Mydosh, P. Raychaudhuri, Yu. Grin. 2005-10-27. High spin polarization in the ferromagnetic filled skutterudites KFe4Sb12 and NaFe4Sb12. https://doi.org/10.1103/physrevb.72.180407

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