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arXiv · 1701.00404

Thermoelectric power factor enhancement by spin-polarized currents - a nanowire case study

Anna Corinna Niemann·Tim Böhnert·Ann-Kathrin Michel·Svenja Bäßler·Bernd Gotsmann·Katalin Neuróhr·Bence Tóth·László Péter·Imre Bakonyi·Victor Vega·Victor M. Prida·Johannes Gooth·Kornelius Nielsch
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Abstract

Thermoelectric (TE) measurements have been performed on the workhorses of today's data storage devices, exhibiting either the giant or the anisotropic magnetoresistance effect (GMR and AMR). The temperature-dependent (50-300 K) and magnetic field-dependent (up to 1 T) TE power factor (PF) has been determined for several Co-Ni alloy nanowires with varying Co:Ni ratios as well as for Co-Ni/Cu multilayered nanowires with various Cu layer thicknesses, which were all synthesized via a template-assisted electrodeposition process. A systematic investigation of the resistivity, as well as the Seebeck coefficient, is performed for Co-Ni alloy nanowires and Co-Ni/Cu multilayered nanowires. At room temperature, measured values of TE PFs up to 3.6 mWK-2m-1 for AMR samples and 2.0 mWK-2m-1 for GMR nanowires are obtained. Furthermore, the TE PF is found to increase by up to 13.1 % for AMR Co-Ni alloy nanowires and by up to 52 % for GMR Co-Ni/Cu samples in an external applied magnetic field. The magnetic nanowires exhibit TE PFs that are of the same order of magnitude as TE PFs of Bi-Sb-Se-Te based thermoelectric materials and, additionally, give the opportunity to adjust the TE power output to changing loads and hotspots through external magnetic fields.

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Anna Corinna Niemann, Tim Böhnert, Ann-Kathrin Michel, Svenja Bäßler, Bernd Gotsmann, Katalin Neuróhr, Bence Tóth, László Péter, Imre Bakonyi, Victor Vega, Victor M. Prida, Johannes Gooth, Kornelius Nielsch. 2017-01-02. Thermoelectric power factor enhancement by spin-polarized currents - a nanowire case study. https://doi.org/10.1002/aelm.201600058

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