Regensburg 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DF: Fachverband Dielektrische Festkörper

DF 14: Thermoelectric and Spincaloric Transport in Nanostructures

DF 14.4: Hauptvortrag

Mittwoch, 13. März 2013, 11:00–11:30, H1

The Planar Nernst Effect and the Search for Thermal Spin Currents in Ferromagnetic Metals — •Barry Zink — University of Denver, Denver, Colorado, USA

In recent years some groups have reported that a pure spin current can be generated simply by applying a thermal gradient to a ferromagnetic material. This effect, called the spin Seebeck effect (SSE), has generated tremendous interest in the interaction of heat, charge and spin in ferromagnetic systems. In this talk we will present our recent measurements of thermoelectric and thermomagnetic effects in thin film metallic ferromagnets made using a micromachined thermal isolation platform that removes potentially confounding effects introduced by a highly thermally conductive bulk substrate. The main result is the observation of a transverse thermopower, called the planar Nernst effect (PNE). Measurements of the field-dependent (traditional) Seebeck effect and anisotropic magnetoresistance (AMR) confirm that the PNE is caused by spin-dependent scattering. This PNE should therefore be present in any attempted measurement of the SSE in a metal system where spin-dependent scattering of electrons occurs. Furthermore our “zero substrate" experiment shows no signal with the symmetry of the SSE, suggesting that the presence of the substrate is required to cause such a signal. This work was performed in collaboration with A. D. Avery, and M. R. Pufall, and supported by the US NSF CAREER award (DMR-0847796)