Regensburg 2019 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 51: Magnetism Poster B
MA 51.57: Poster
Donnerstag, 4. April 2019, 15:00–18:00, Poster C
Spin Seebeck effect in ultra-thin gadolinium iron garnet films — •Maxim Dietlein1,2, Stephan Geprägs1, and Rudolf Gross1,2,3 — 1Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Garching, Germany — 2Fakultät für Physik, Technische Universität München, Garching, Germany — 3Nanosystems Initiative Munich, München, Germany
The generation of a spin current in a magnetic material as a result of a temperature gradient known as spin Seebeck effect (SSE) has triggered intense research in the field of spin caloritronics. Recently, it has been demonstrated that the SSE is sensitive to the complexity of the magnon dispersion relation and can therefore be used as a probe for magnon properties in complex magnets [1]. In magnetically compensated ferrimagnetic insulator Gd3Fe5O12 (GdIG) | heavy metal (Pt) heterostructures, the temperature dependence of the SSE amplitude shows two sign changes. One sign change is caused by the reversal of the sublattice magnetizations at the magnetic compensation temperature of GdIG, while the second sign change arises from the superposition of two main magnon modes with opposite chirality. We here discuss the temperature dependence of the SSE signal in ultra-thin epitaxial GdIG|Pt heterostructures on Y3Al5O12 (YAG) substrates. We show that the temperature of both SSE sign changes as well as the SSE amplitude in GdIG|Pt heterostructures are highly sensitive to the thickness of the GdIG thin film. With this, we are able to draw conclusion on the magnon dispersion in ultra-thin GdIG films. [1] S. Geprägs et al., Nature Comm. 7, 10452 (2016).