Speaker
Description
Nickel monosilicides (NiSi) crystallize in various orthorhombic, hexagonal, and/or cubic structures, exhibiting rich polymorphism with unique physical properties. There have been surging fundamental and practical interests in their potential candidacy as emerging magnetic topological materials that are free of rare-earth elements. Here, by combining density functional theory and magnetotransport, we have investigated the lattice stability, phonon dispersion, anisotropy, magnetic ordering, electronic structure, topological features, and transport properties of known NiSi phases, establishing a comprehensive understanding of NiSi polymorphs and their technological relevance. In the orthorhombic MnP-type phase, we have examined its highly anisotropic thermal expansion, robust antiferromagnetic ordering under ambient conditions, and exceptionally low electrical resistivity suitable as contact materials in chip manufacturing. We have further characterized the strain tunability of the Weyl nodes and Fermi arcs identified in cubic ε-FeSi-type phase. Collectively, our results have demonstrated novel nickel monosilicides as a promising platform for advancing spintronic and microelectronic applications.
The research was supported by Canada Research Chairs (CRC) Program, NSERC Discovery Grant RGPIN-2024-06497, ARO Grant Number W911NF-25-1-0215, Canada Foundation for Innovation (CFI), Ontario Research Fund (ORF), Compute Ontario and Digital Research Alliance of Canada.
| Keyword-1 | Antiferromagnetism |
|---|---|
| Keyword-2 | Weyl semimetal |
| Keyword-3 | Density functional theory |