Enhancement Of Charge-To-Spin Current Conversion In A Ni/Pt Bilayer Film Detected By Spin Peltier Effect (Vol 59, 050901, 2020)

We demonstrate the enhancement of charge-to-spin current conversion by a ferromagnet/paramagnet interface. The enhancement is confirmed by comparing the spin Peltier effect (SPE) between Ni/Pt/yttrium-iron-garnet (YIG) and Pt/YIG hybrid structures, where the SPE signal is proportional to the spin current generated in the Ni/Pt or Pt layer. The SPE signal normalized by charge current density for the Ni/Pt/YIG system increases by 65% compared to the Pt/YIG system, which cannot be explained by other thermoelectric and thermo-spin effects. This result suggests the presence of additive charge-to-spin current conversion at the Ni/Pt interface, providing simple ways to improve spin-injection efficiency.