Authors:	Kalappattil, Vijaysankar Geng, Rugang Das, Raja Pham, Minh Luong, Hoang Nguyen, Toa Popescu, Adrian Woods, Lilia M. Kläui, Mathias Srikanth, Hariharan Phan, Manh-Huong
Title:	Giant spin Seebeck effect through an interface organic semiconductor
Online publication date:	6-Dec-2021
Year of first publication:	2020
Language:	english
Abstract:	Interfacing an organic semiconductor C-60 with a non-magnetic metallic thin film (Cu or Pt) has created a novel heterostructure that is ferromagnetic at ambient temperature, while its interface with a magnetic metal (Fe or Co) can tune the anisotropic magnetic surface property of the material. Here, we demonstrate that sandwiching C-60 in between a magnetic insulator (Y3Fe5O12:YIG) and a non-magnetic, strong spin-orbit metal (Pt) promotes highly efficient spin current transport via the thermally driven spin Seebeck effect (SSE). Experiments and first principles calculations consistently show that the presence of C-60 reduces significantly the conductivity mismatch between YIG and Pt and the surface perpendicular magnetic anisotropy of YIG, giving rise to enhanced spin mixing conductance across YIG/C-60/Pt interfaces. As a result, a 600% increase in the SSE voltage (V-LSSE) has been realized in YIG/C-60/Pt relative to YIG/Pt. Temperature-dependent SSE voltage measurements on YIG/C-60/Pt with varying C-60 layer thicknesses also show an exponential increase in V-LSSE at low temperatures below 200 K, resembling the temperature evolution of spin diffusion length of C-60. Our study emphasizes the important roles of the magnetic anisotropy and the spin diffusion length of the intermediate layer in the SSE in YIG/C-60/Pt structures, providing a new pathway for developing novel spin-caloric materials.
DDC:	530 Physik 530 Physics
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 08 Physik, Mathematik u. Informatik
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-5325
Version:	Accepted version
Publication type:	Zeitschriftenaufsatz
Document type specification:	Scientific article
License:	In Copyright
Information on rights of use:	http://rightsstatements.org/vocab/InC/1.0/
Journal:	Materials Horizons 7 5
Pages or article number:	1413 1420
Publisher:	RSC Publ.
Publisher place:	Cambridge
Issue date:	2020
ISSN:	2051-6347
Publisher URL:	https://doi.org/10.1039/C9MH01498E
Publisher DOI:	10.1039/C9MH01498E
Appears in collections:	JGU-Publikationen