title: Seebeck effect in magnetic tunnel junctions.
abstract: Creating temperature gradients in magnetic nanostructures has resulted in a new research direction, that is, the combination of magneto- and thermoelectric effects. Here, we demonstrate the observation of one important effect of this class: the magneto-Seebeck effect. It is observed when a magnetic configuration changes the charge-based Seebeck coefficient. In particular, the Seebeck coefficient changes during the transition from a parallel to an antiparallel magnetic configuration in a tunnel junction. In this respect, it is the analogue to the tunnelling magnetoresistance. The Seebeck coefficients in parallel and antiparallel configurations are of the order of the voltages known from the charge-Seebeck effect. The size and sign of the effect can be controlled by the composition of the electrodes' atomic layers adjacent to the barrier and the temperature. The geometric centre of the electronic density of states relative to the Fermi level determines the size of the Seebeck effect. Experimentally, we realized 8.8% magneto-Seebeck effect, which results from a voltage change of about -8.7 μV K⁻¹ from the antiparallel to the parallel direction close to the predicted value of -12.1 μV K⁻¹. In contrast to the spin-Seebeck effect, it can be measured as a voltage change directly without conversion of a spin current.
authors.forename: Marvin
authors.initials: M
authors.lastname: Walter
authors.forename: Jakob
authors.initials: J
authors.lastname: Walowski
authors.forename: Vladyslav
authors.initials: V
authors.lastname: Zbarsky
authors.forename: Markus
authors.initials: M
authors.lastname: Münzenberg
authors.forename: Markus
authors.initials: M
authors.lastname: Schäfers
authors.forename: Daniel
authors.initials: D
authors.lastname: Ebke
authors.forename: Günter
authors.initials: G
authors.lastname: Reiss
authors.forename: Andy
authors.initials: A
authors.lastname: Thomas
authors.forename: Patrick
authors.initials: P
authors.lastname: Peretzki
authors.forename: Michael
authors.initials: M
authors.lastname: Seibt
authors.forename: Jagadeesh S
authors.initials: JS
authors.lastname: Moodera
authors.forename: Michael
authors.initials: M
authors.lastname: Czerner
authors.forename: Michael
authors.initials: M
authors.lastname: Bachmann
authors.forename: Christian
authors.initials: C
authors.lastname: Heiliger