Iron-based binary ferromagnets for transverse thermoelectric conversion

Omnidirectional Control of Large Electrical Output in a Topological Antiferromagnet

“…A magnetically robust feature observed in our study is quite useful to retain the octupole direction of the grains distributed in a printing ink along a required direction. Furthermore, the performance of the ANE thermopiles has reached the same order as the reported values of commercial Seebeck‐type devices (e.g., iTi HT‐50: 0.4 mV W −1 , Flux Teq PHFS‐01: 0.9 mV W −1 , and Hukseflux FHF01: 1.8 mV W −1 ), and would match or even exceed high‐end devices (e.g., EKO MF‐180: 33 mV W −1 and HIOKI Z2012: 142 mV W −1 ) with further reduction of the wire width (5 m → 500 nm) and enhancement of the anomalous Nernst coefficient (0.35 V/K [ 21 ] → 6 V/K [ 31,55 ] ). In addition, the low thermal insulation is the key for developing a heat flux sensor, as the insulation may disturb the flux itself and cause the slow response.…”

“…[ 21,31,53–56 ] First, the orthogonal configuration of the voltage output to the heat flow enables the lateral thermopile structure consisting of a magnetic material and electrodes (Figure 6b), formed on the various substrate including flexible films. [ 55,56 ] Second, as the ANE voltage V ANE follows the relation, V ANE = S ANE × l × ∇ T film , namely, being proportional to the anomalous Nernst coefficient S ANE , the total length l of the magnetic circuit, and the temperature gradient ∇ T film , the thin film device would be the best for the sensor as its low thermal resistance would not disturb the heat flow across the specimen. Thus, the conventional thin film fabrication and lithography methods are applicable for fabrication, reducing the number of production processes and the associated costs in comparison with the conventional Seebeck case.…”

A Monomaterial Nernst Thermopile with Hermaphroditic Legs

“…Moreover, the idea behind this work can be used to make thermopiles with other magnetic materials with a larger ANE, known [9,10] or yet to be discovered. [39] Ferromagnets with strong magneto-crystalline anisotropy or shape anisotropy could be candidates.…”

“…The PHE signal emerges inside the hysteresis and, as seen in Figure 3a, is restricted to a [1,3] has a vertical structure and is made of two different types of materials labeled N and P. The voltage drop is along the direction of temperature difference. b) The Nernst thermopile [9,10] exploiting the ANE has a planar structure and is suitable for thin film applications. The voltage drop is perpendicular to the direction of thermal gradient, and can be switched by the direction of magnetization.…”

“…[1,3] This led several authors to consider Nernst thermopiles using the anomalous Nernst effect (ANE), a transverse voltage drop perpendicular to both the magnetization and heat current, which has the potential to compensate for the shortcomings in Seebeck case. [8][9][10][11][12][13][14][15] As the thermoelectric counterpart of anomalous Hall effect (AHE), ANE has proved to be a sensitive probe of the Berry curvature near the Fermi level. [13,[16][17][18][19][20][21][22] In contrast to the Seebeck thermopile, a Nernst thermopile [9,10] has a planar structure with V ⊥ ∇T (see Figure 1b).…”