Loughborough University
Leicestershire, UK
LE11 3TU
+44 (0)1509 263171
Loughborough University

Loughborough University Institutional Repository

Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/35293

Title: Spin-dependent Seebeck coefficients of Ni80Fe20 and Co in nanopillar spin valves
Authors: Dejene, F.K.
Flipse, J.
van Wees, B.J.
Issue Date: Jul-2012
Publisher: © American Physical Society
Citation: DEJENE, F.K., FLIPSE, J. and VAN WEES, B.J., 2012. Spin-dependent Seebeck coefficients of Ni80Fe20 and Co in nanopillar spin valves. Physical Review B, 86 (2), 024436.
Abstract: We have experimentally determined the spin-dependent Seebeck coefficient of permalloy (Ni80Fe20) and cobalt (Co) using nanopillar spin valve devices, a stack of two ferromagnetic layers separated by a nonmagnetic layer. The devices were specifically designed to separate heat-related effects from charge-related effects. A heat current, with no accompanying charge current, through the nanopillar spin valve leads to a thermovoltage proportional to the spin-dependent Seebeck coefficient SS = S↑ − S↓ of the ferromagnet, where S↑ and S↓ are the Seebeck coefficient for spin-up and spin-down electrons. By using a three-dimensional finite-element model based on spin-dependent thermoelectric theory, whose input material parameters were measured in separate devices, we were able to accurately determine a spin-dependent Seebeck coefficient of −1.8 μV K−1 and −4.5 μV K−1 for cobalt and permalloy, respectively, corresponding to a Seebeck coefficient polarization PS = SS /SF of 0.08 and 0.25, where SF is the Seebeck coefficient of the ferromagnet. The results are in agreement with earlier theoretical work in Co/Cu multilayers and spin-dependent Seebeck and spin-dependent Peltier measurements in Ni80Fe20/Cu spin valve structures.
Description: This paper was published in the journal Physical Review B and the definitive published version is available at https://doi.org/10.1103/PhysRevB.86.024436.
Version: Accepted for publication
DOI: 10.1103/PhysRevB.86.024436
URI: https://dspace.lboro.ac.uk/2134/35293
Publisher Link: https://doi.org/10.1103/PhysRevB.86.024436
ISSN: 2469-9950
Appears in Collections:Published Articles (Physics)

Files associated with this item:

File Description SizeFormat
1206.1659v1.pdfAccepted version3.94 MBAdobe PDFView/Open

 

SFX Query

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.