Spin Seebeck Power Conversion

Abstract

Spin caloritronics is the science and technology to control spin, charge, and heat currents in magnetic nanostructures. The spin degree of freedom provides new strategies for thermolelectric power generation that have not yet been fully explored. After an elementary introduction into conventional thermoelectrics and spintronics, we give a brief review of the physics of spin caloritronics. We discuss spin-dependent thermoelectrics based on the the two-current model in metallic magnets as well as the spin Seebeck and Peltier effects that are based on spin wave excitations in ferromagnets. We derive expressions for the efficiency and figure of merit ZT of several spin caloritronic devices.Comment: 14 pages, 14+ figure

Picosecond Spin Seebeck Effect

“…Introduction.-Spin transport in magnetic insulators and through metal/insulator interfaces is extensively studied in the fields of spintronics and spincaloritronics, providing new routes for information technologies and heat-to-electricity conversion [1][2][3]. A key role in spin caloritronics is played by the longitudinal spin Seebeck effect (LSSE), which describes spin transport through the interface between a normal metal and a magnetic insulator upon heat transport through that interface [4].…”

Unconventional scaling and significant enhancement of the spin Seebeck effect in multilayers

“…This has contributed to the rapid expansion of the field of thermospin effects [16][17][18][19][20], which is focused on the study of the correlation between charge, heat, and spin currents in magnetic materials. Furthermore, the observation of the SSE in magnetic insulators [8] is of great interest for potential applications as in energy harvesting [21,22], since it allows the generation of electric voltages without the thermal loss associated with mobile charge carriers, opening the possibility to explore magnetic oxides, not previously studied in thermoelectric generation. Another inherent advantage of the SSE is that it involves properties of at least two different materials that can be optimized independently.…”

Spincaloritronic Measurements: A Round Robin Comparison of the Longitudinal Spin Seebeck Effect

“…Possible applications of the widely investigated SSE materials are sensors [29]- [31], spin-analogues of thermoelectric generators [32]- [35] and devices designed in view of the development of spintronic circuits, such as spin batteries [36]. For what concerns the spin-thermoelectric effects, if we make a parallel with the usual thermoelectric materials [37] where ZT = ε 2 σ / (kT ), we expect a good figure of merit for materials with poor thermal conductivity k and large spin conductivity σ as are found in insulating ferrimagnets, like YIG and ferrites.…”