Abstract
High quality single crystals have been investigated by magnetization, electron transport, and Andreev reflection spectroscopy. In the ferromagnetic ground state, the saturation magnetic moment of each unit cell corresponds to an integer number of electron spins (), and the Hall effect measurements suggest -type charge carriers. Spin polarizations as high as 97% were obtained from fits of the differential conductance spectra of /Pb junctions with the modified Blonder-Tinkham-Klapwijk theory. The temperature and bias-voltage dependencies of the subgap conductance are consistent with recent theoretical calculations based on spin active scatterings at a superconductor–half-metal interface. Our results suggest that is a half-metal, in agreement with theoretical calculations that also predict undoped is a magnetic Weyl semimetal.
- Received 28 January 2015
DOI:https://doi.org/10.1103/PhysRevLett.115.087002
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