Non equilibrium thermodynamics of the spin Seebeck and spin Peltier effects
Lundi 20 mars 2017 16:00
- Duree : 1 heure
Lieu : SPINTEC, Bât 10-05 - CEA Grenoble, 17 rue des martyrs
Orateur : Vitorrio BASSO (Istituto Nazionale di Ricerca Metrologica, Turin, Italy)
The spin Seebeck and spin Peltier effects are the thermomagnetic analogous of the well known Seebeck and Peltier effects of thermoelectrics in which the electric current is substituted by a magnetic moment current (also called spin current) [1]. Both effects are realized by establishing a spin current at the junction between a metal with a large spin Hall effect (i.e. platinum, Pt) and a ferromagnetic insulator (i.e. yttrium iron garnet, YIG). In the spin Seebeck effect, the spin current is generated by a temperature gradient over the YIG and is detected as a transverse electric current on the Pt. In the spin Peltier one, the spin current is generated by the Pt and its diffusion into the YIG generates a heat current. We approach the problem of the joint transport of magnetic moment and heat from the point of view of non-equilibrium thermodynamics. We show that the profiles of the magnetization current for both the spin Seebeck and the spin Peltier effect can be calculated by a diffusion equation containing, as a parameter, the absolute thermomagnetic power coefficient of YIG [2]. This coefficient can be determined by experiments and then compared to the results of first principles theories. In the seminar will discuss the current state of the art in the physical interpretation of these thermomagnetic effects and show that they can be attributed to the diffusive transport of thermal spin waves in the ferromagnet.
[1] H. Adachi, K. Uchida, E. Saitoh and S. Maekawa, Rep. Prog. Phys. 76, 036501 (2013).
[2] V. Basso, E. Ferraro, A. Magni, A. Sola, M. Kuepferling and M. Pasquale, Phys. Rev. B 93, 184421 (2016) doi : 10.1103/PhysRevB.93.184421 ; V. Basso, E. Ferraro and M. Piazzi, Phys. Rev. B 94, 144422 (2016) doi : 10.1103/PhysRevB.94.144422
Contact : olivier.boulle@cea.fr
Discipline évènement : (Physique)
Nature évènement : (Séminaire)
Evènement répétitif : (Séminaire nanomagnétisme et spintronique)
Site de l'évènement : Site CEA avec accès badge
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