Abstract
The spin polarization of ferromagnetic alkali-metal iron antimonides and is studied by point-contact Andreev reflection using superconducting Nb and Pb tips. From these measurements an intrinsic transport spin polarization of 67% and 60% for the K and Na compound, respectively, is inferred, which establishes these materials as a class of highly spin-polarized ferromagnets. The results are in accord with band structure calculations within the local spin density approximation that predict nearly 100% spin polarization in the density of states. We discuss the impact of calculated Fermi velocities and spin fluctuations on .
- Received 23 July 2005
DOI:https://doi.org/10.1103/PhysRevB.72.180407
©2005 American Physical Society