We report the synthesis and magnetic characterization of WFeB and identify it as a metallic d-wave altermagnet representative of a broader TiNiSi-type family. Neutron diffraction, M\"ossbauer spectroscopy, and magnetometry establish a collinear altermagnetic ordering confirmed by first-principles calculations. The electronic structure shows a nonrelativistic spin splitting of approximately 100 meV, but it also supports a strong spin-splitter transport response. This demonstrates that efficient spin-current generation can occur even with such modest band splitting. Symmetry analysis shows that selected film orientations permit deterministic switching of the N\'eel vector by current-induced staggered torques, enabling electrical control of a perpendicular spin-splitter response. These results establish WFeB and related TiNiSi-type antiferromagnets as a platform for electrically switchable charge-to-spin conversion driven by altermagnetic symmetry.
@article{arxiv.2604.00325,
title = {Metallic d-wave altermagnetism in WFeB: a platform for electrically switchable perpendicular spin-splitter response},
author = {Eranga H. Gamage and Zhen Zhang and Subhadip Pradhan and Ajay Kumar and David R. Ramgern and V. Ovidiu Garlea and Yaroslav Mudryk and Saeed Kamali and Douglas Warnberg and Kirill D. Belashchenko and Vladimir Antropov and Kirill Kovnir},
journal= {arXiv preprint arXiv:2604.00325},
year = {2026}
}