Spin Seebeck effect in the antiferromagnet nickel oxide at room temperature*

NiO is a room-temperature antiferromagnetic (AF) insulator with important applications in AF spintronics. It is considered a prototypical AF material with a simple magnetic structure with two sublattice spins aligned in easy planes and having small in-plane magnetic anisotropy. Recently the spin Seebeck effect (SSE) has been observed, at low temperatures and high magnetic fields, in bilayers made of the antiferromagnets MnF₂ and Cr₂O₃ with Pt-capping layer. Usually, the SSE is detected by an electric voltage generated in the metallic layer in contact with the magnetic film produced by the spin to charge current conversion through the inverse spin Hall effect (ISHE) [1]. Here we report measurements of the SSE in a film of antiferromagnetic NiO at room temperature and low magnetic fields. The detection of the spin current generated by the thermal gradient in the NiO layer is made by means of the ISHE in the non magnetic metals Pt and Ta, in the AF metal IrMn and in the ferromagnetic metal permalloy [2].
[1] J. Holanda et. al., Phys. Rev. B 95, 134432 (2017).
[2] J. Holanda et. al., Appl. Phys. Lett. 111, 000000 (2017) - Accepted.