Temperature Dependence of the Anomalous Nernst Coefficient for Ni₈₀Fe₂₀ Determined with Metallic Nonlocal Spin Valves

The anomalous Nernst effect, which generates an out-of-plane charge voltage in response to a thermal gradient perpendicular to the magnetization of a ferromagnet, can play a significant role in any spintronic device where large thermal gradients exist.[1] Since they typically include features deep within the submicron regime, nonlocal spin valves can be made very sensitive to this effect by lowering the substrate thermal conductance.[2] Thus, material parameters are extremely important to the performance of these devices. Although studies have been conducted into the thickness dependence of the anomalous Hall coefficient for permalloy, little is known about the temperature dependence of the anomalous Nernst coefficient.[3,4]

Here, we use nonlocal spin valves suspended on thin silicon nitride membranes to determine the temperature dependence of the anomalous Nernst coefficient of 35 nm thick permalloy (the NiFe alloy with 80% Ni) from 78 K to 300 K.

[1] Chuang, et al. PRB 96 (2017)
[2] Bennet, et al. PRB 100 (2019)
[3] Zhang, et al. J. Appl. Phys. 114 (2013)
[4] Zhang, et al. AIP Adv. 6 (2016)