Large magnetoresistance and temperature-driven spin filter effect in spin valve based on half Heusler alloy

High spin-injection-efficiency (SIE) and thermal spin-filter-effect (SFE) from a magnetic material to a barrier material are crucial to the high performance of a spintronic device and a spin caloritronic device, respectively. By performing a nonequilibrium Green's function combined with first-principles calculations, we study the voltage-driven and temperature-driven spin transport properties of a half Heusler alloy RuCrAs based spin valve with different atom-terminated interfaces. The spin valve with a CrAs-top (or Ru-top) interface structure has an ultrahigh equilibrium magnetoresistance (MR) ratio of similar to 1.56 x 10(9)% (or similar to 5.14 x 10(8)%), similar to 100% SIE, a large MR ratio, and high spin current intensity under bias voltage, suggesting that it has a great potential application in spintronic devices. The spin valve with the CrAs-top (or CrAs-bri) interface structure has a perfect SFE due to its very high spin polarization of temperature-driven currents, and it is useful in spin caloritronic devices.

Automated summary

High spin-injection-efficiency (SIE) and thermal spin-filter-effect (SFE) are crucial for the high performance of spintronic and spin caloritronic devices. In this study, we investigate the spin transport properties of a RuCrAs-based spin valve with different atom-terminated interfaces using nonequilibrium Green's function and first-principles calculations. The spin valve with a CrAs-top (or Ru-top) interface structure exhibits a high equilibrium magnetoresistance (MR) ratio, 100% SIE, large MR ratio, and high spin current intensity under bias voltage, making it promising for spintronic applications. The spin valve with the CrAs-top (or CrAs-bri) interface structure shows perfect SFE due to its high spin polarization of temperature-driven currents, making it useful for spin caloritronic devices.