Low temperature spin Seebeck effect in antiferromagnetic V₂O₃thin film.

The spin Seebeck effect (SSE) involves the generation of spin current in the presence of a heat flux through a magnetically active material. The SSE has been observed in many antiferromagnets (AFM), such as Cr₂O₃, NiO, and MgF₂; however, the mechanism of AFM SSE is still under discussion, including the relative contributions of Néel order, particular sublattices, or in noncolinear AFMs, the net magnetization. Here we present a systematic study of the longitudinal SSE (LSSE) in insulating monoclinic AFM V₂O₃ films at low temperatures. The LSSE grows linearly with increasing field at low fields and saturates at high field below 5 K. The LSSE shows the expected cosine angular dependence with the in-plane field orientation and is linear in heater power. The magnitude of the LSSE is nonmonotonic as a function of temperature, with a peak at low temperatures; the peak temperature grows with increasing field. We compare the LSSE between paramagnetic VO₂ and AFM V₂O₃, and other AFM systems.