The magnetic moment of electrons is the special focus of attention in spintronics, which is one of the research priorities in Theoretical Solid State Physics. The Kratzer and Entel research groups are working together to investigate a type of spintronics in which a temperature difference is used to ­generate a spin-polarised current. The necessary electrical voltage is described by the magneto-Seebeck coefficient. For this field of research, which is funded by the German Research Foundation (DFG) under a Priority Programme, the term spincaloritronics was coined. The methods used in the research group to calculate the electronic structure (density functional theory) permit them to make material-specific predictions and are therefore useful in the selection of suitable materials and structures for spincaloritronics.

Our calculations showed, for example, that it is possible using the magneto-Seebeck effect to read out the direction of magnetisation of a thin-film component made of copper and cobalt. According to our theoretical predictions, specific metal alloys (Heusler alloys, which are semimetallic ferromagnets) should be particularly suitable for thermal generation of a spin-polarised current. The magneto-Seebeck coefficient of layered structures containing a thin film of a Heusler alloy was calculated for different combinations of materials. The Heusler layer was sandwiched between two contact layers of either platinum or aluminium. The platinum contacts make it possible to experimentally verify the spin-polarised current, while aluminium contacts are useful if the spin-polarised current is to be maintained over longer distances.