Single spin channels in Fe-doped CoTiSb semiconductor

• The Fe-based single spin channels are designed.
• The Fe–Sb and Fe–V atomic chains show a half-metallic characteristic.
• The Fe–Fe atomic chains show a spin-gapless characteristic.
• Our work bring a different perspective into spintronics device.

The Fe-based single atomic chains are designed in the semiconductive CoTiSb matrix by continuously substituting Fe for Ti, Ti–Sb or Co in [0 0 1] crystallographic direction. The electronic structures and magnetic properties of CoTiSb supercells with the Fe-based single atomic chains have been investigated using the first-principles calculations. We predict that the single atomic chains of Fe–Sb (achieved by substituting Fe for Ti) and Fe-vacancy (achieved by substituting Fe for Co) show a 100% spin polarization and form a very small single spin channel. The single atomic chains of Fe–Fe (achieved by substituting Fe for Ti and Sb) show a spin-gapless characteristic.