Recent advances in thermomagnetic devices for spin-caloritronic phenomena

The thermoelectric energy harvesting technique is emerging out as a potential way to generate an alternative energy source, whereas the thermomagnetic approach has also put some rays of hope for the generation of an alternative energy source and opened a significant interest in the field of spin caloritronics. Spin caloritronics, which exploits the interaction between spin and heat, offers a promising path to design thermomagnetic devices. Among them, the anomalous Nernst effect (ANE), a thermal counterpart of the anomalous Hall effect (AHE) has received significant attention since earlier times in the field of spin caloritronics. ANE, which arises from the fictitious fields in the momentum space, is invariably a combination of charge in magnets, spin, and heat. Similarly, the spin-Seebeck effect (SSE) describes the generation of spin voltage due to the temperature gradient applied in ferromagnetic (FM) materials. This phenomenon allows the thermal injection of spin current from the FM into the connected heavy nonmagnetic metal (NM), where the spin interacts to generate thermoelectric voltage due to the inverse spin Hall effect (ISHE). The role of magnon and phonon degrees of freedom in the SSE has been highlighted by recent experimental techniques. In this article, we briefly review the SSE and the ANE, including effective methodologies and device engineering for the advancement of their thermo-electromagnetic applications. The motivation of this review article is to provide a thorough understanding of thermomagnetic phenomena by delving into the drawbacks and suggesting potential ways to improve overall aspects of SSE and ANE characteristics.