Half-Metallicity in One-Dimensional Metal Trihydride Molecular Nanowires

The development of one-dimensional (1D) molecular nanowires with high spin-polarization is important for both fundamental research and practical applications in nanoscale spintronics. Herein, we report new 1D metal trihydride molecular nanowires MH₃ (M = Sc, Cr, Mn, and Co) with versatile magnetic properties on the basis of first-principles calculations and molecular assembly of their molecular motifs. Among the 1D nanowires considered, CrH₃, MnH₃, and CoH₃ are either antiferromagnetic or ferromagnetic in their ground states. In particular, CoH₃ nanowire is a half-metal, which ideally could provide 100% spin-polarized currents. Moreover, carrier doping in MnH₃ nanowire can induce a transition from ferromagnetic metal to half-metal. Strong metal-metal interaction in 1D MH₃ nanowires is responsible to versatile magnetic properties and high Curie temperature. Born-Oppenheimer molecular dynamics simulation indicates that these nanowires are stable at elevated temperature. In particular, the ScH₃ nanowire appears to have the highest structural stability at temperature 1200 K. These novel properties of 1D MH₃ nanowires render their potential applications in nanoscale spintronics.