Mapping metallic d-wave altermagnetism across the TiNiSi structural family

Abstract

The prospect of using altermagnets as switchable sources of perpendicularly polarized spin currents has intensified the search for candidate materials, yet metallic d-wave systems with sizable spin-splitter responses remain scarce. Here, we identify an empirical magnetic motif that supports metallic d-wave altermagnetism in the TiNiSi structural family: ferromagnetically ordered zigzag chains with antiferromagnetic interchain coupling in a relatively low-symmetry crystal environment. The TiNiSi structure type combines this motif with broad chemical flexibility and competing magnetic ground states. By combining first-principles screening of thermodynamic stability and magnetic ground states across 280 ternary systems, we identify 16 metallic d-wave altermagnets. This set recovers four experimentally known members---WFeB, NbMnP, TaMnP, and NbMnAs---and yields 12 new predictions, of which ScMnP, TaMnAs, ScMnAs, MoMnAs, MoMnSi, and WMnSi are the most promising. Noncollinear calculations indicate that the collinear altermagnetic configuration is the ground state across them. Each of the six leading new candidates has a nonzero spin-splitter angle and a finite anomalous Hall conductivity. Notably, ScMnP and TaMnAs exhibit strong spin-splitter responses despite modest altermagnetic band splitting. These results establish TiNiSi-type metallic d-wave altermagnets as a chemically versatile platform for efficient charge-to-spin conversion and provide an empirical magnetic-motif-guided route to identifying further candidates.