Efficient Thermo‐Spin Conversion in van der Waals Ferromagnet FeGaTe

Abstract

Recent discovery of 2D van der Waals magnetic materials has spurred progress in developing advanced spintronic devices. A central challenge lies in enhancing the spin‐conversion efficiency for building spin‐logic or spin‐memory devices. Here, the anomalous Hall and Nernst effects are systematically investigated to uncover significant spin‐conversion effects in above‐room‐temperature van der Waals ferromagnet FeGaTe with perpendicular magnetic anisotropy. The anomalous Hall effect demonstrates an efficient electric spin‐charge conversion with a notable spin Hall angle of over 6%. In addition, the anomalous Nernst effect produces a significant transverse voltage at room temperature without a magnetic field, displaying unique temperature dependence with a maximum transverse Seebeck coefficient of 440 nV K−1 and a Nernst angle of ≈62%. Such an innovative thermoelectric signal arises from the efficient thermo‐spin conversion effect, where the up‐spin and down‐spin electrons move in opposite directions under a temperature gradient. The present study highlights the potential of FeGaTe to enhance thermoelectric devices through efficient thermo‐spin conversion without the need for a magnetic field.

Optimization of thermo-spin voltage in vertical nanostructures by geometrical means

“…The ANE can be regarded as the thermal effect of the anomalous Hall effect in FM metals [23]. The ANE, which is analyzed through the spin-charge conversion model, can be phenomenologically explained by considering the interaction of SDSE-induced thermo-spin currents with the ISHE in the FM [20,24,25]. So, the electric field in FM could be expressed as:…”