Spin-caloric transport in magnetoresistive nanostructures

• Applicants: Professor Dr. Jean-Philippe Ansermet; Professor Dr. Günter Reiss; Dr. Robert Zierold, since 2/2016
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 198550269

This project will explore spin-caloritronic transport in different magnetoresistive nanostructures: individual magnetic nanowires which show AMR (Anisotropic Magneto Resistance) or GMR (Giant MR), and magnetic multilayer films which exhibit GMR and TMR (Tunnel MR). 3ω methods will be employed to observe spin-dependent thermal conductivity changes for the thin-film systems in the cross-plane direction, as well as for the nanowire systems. For the latter, simultaneous MR measurements may show spin-dependent changes in the Lorenz number, thus analysing the Wiedemann Franz law. The 3ω method for thin-films provides information about the thermal conductivity anisotropy. In a further experiment spin-dependent changes in the Seebeck coefficient of the nanowire systems will be investigated. The lithographic approach in this work will provide absolute values of the nanowire’s Seebeck coefficient. By combining the results, we will calculate the thermoelectric conversation efficiency of the nanowire systems and determine their highest point of efficiency as a function of magnetic field. Thus, we will evaluate if magnetoresistive systems can be useful for cooling magnetoelectronic devices. Within the consortium, we will study ferromagnetic resonance in nanowires with embedded spin-valves and the interactions of spin waves under strong heat flows.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1538: Spin Caloric Transport (SpinCaT)
• International Connection: Switzerland
• Partner Organisation: Schweizerischer Nationalfonds (SNF)
• Ehemaliger Antragsteller: Professor Dr. Kornelius Nielsch, until 2/2016