Print Email Facebook Twitter Thermal spin pumping and magnon-phonon-mediated spin-Seebeck effect Title Thermal spin pumping and magnon-phonon-mediated spin-Seebeck effect Author Uchida, K. Ota, T. Adachi, H. Xiao, J. Nonaka, T. Kajiwara, Y. Bauer, G.E.W. Maekawa, S. Saitoh, E. Faculty Applied Sciences Department QN/Quantum Nanoscience Date 2012-05-17 Abstract The spin-Seebeck effect (SSE) in ferromagnetic metals and insulators has been investigated systematically by means of the inverse spin-Hall effect (ISHE) in paramagnetic metals. The SSE generates a spin voltage as a result of a temperature gradient in a ferromagnet, which injects a spin current into an attached paramagnetic metal. In the paramagnet, this spin current is converted into an electric field due to the ISHE, enabling the electric detection of the SSE. The observation of the SSE is performed in longitudinal and transverse configurations consisting of a ferromagnet/paramagnet hybrid structure, where thermally generated spin currents flowing parallel and perpendicular to the temperature gradient are detected, respectively. Our results explain the SSE in terms of a two-step process: (1) the temperature gradient creates a non-equilibrium state in the ferromagnet governed by both magnon and phonon propagations and (2) the non-equilibrium between magnons in the ferromagnet and electrons in the paramagnet at the contact interface leads to “thermal spin pumping” and the ISHE signal. The non-equilibrium state of metallic magnets (e.g., Ni81Fe19) under a temperature gradient is governed mainly by the phonons in the sample and the substrate, while in insulating magnets (e.g., Y3Fe5O12), both magnon and phonon propagations appear to be important. The phonon-mediated non-equilibrium that drives the thermal spin pumping is confirmed also by temperature-dependent measurements, giving rise to a giant enhancement of the SSE signals at low temperatures. Subject ferromagnetic materialsiron alloysnickel alloysparamagnetic materialsphonon-magnon interactionsSeebeck effectspin Hall effectspin polarised transportyttrium compounds To reference this document use: http://resolver.tudelft.nl/uuid:8ee3cff4-b724-4091-8306-5b4bbbbe7001 DOI https://doi.org/10.1063/1.4716012 Publisher American Institute of Physics ISSN 0021-8979 Source http://jap.aip.org/resource/1/japiau/v111/i10/p103903_s1 Source Journal of Applied Physics, 111 (10), 2012 Part of collection Institutional Repository Document type journal article Rights © 2012 The Author(s)American Institute of Physics Files PDF Bauer_2012.pdf 2.14 MB Close viewer /islandora/object/uuid:8ee3cff4-b724-4091-8306-5b4bbbbe7001/datastream/OBJ/view