Jan-Michael Schmalhorst

TL;DR: In this article, the spin Hall magnetoresistance effect in ferromagnetic insulator/platinum and non-ferromagnet hybrid structures was investigated and quantitatively analyzed.

Abstract: The transport properties of magnetic tunnel junctions with different (110)-textured Heusler alloy electrodes such as Co2MnSi, Co2FeSi or Co2Mn0.5Fe0.5Si, AlOx barrier, and Co–Fe counterelectrode are investigated. The bandstructure of Co2Mn1−xFexSi is predicted to show a systematic shift in the position of the Fermi energy EF through the gap in the minority density of states while the composition changes from Co2MnSi toward Co2FeSi. Although this shift is indirectly observed by x-ray photoemission spectroscopy, all junctions show a large spin polarization of around 70% at the Heusler alloy/Al–O interface and are characterized by a very similar temperature and bias voltage dependence of the tunnel magnetoresistance. This suggests that these transport properties of these junctions are dominated by inelastic excitations and not by the electronic bandstructure.

TL;DR: It is proposed that this characteristic of femtosecond optical excitation of half-metals enables the establishment of a novel and fast characterization tool for this highly important material class used in spin-electronic devices.

TL;DR: After the identification of the contribution of the planar and anomalous Nernst effects, the upper limit for the transverse spin Seebeck effect is found, which is several orders of magnitude smaller than previously reported.

TL;DR: In this article, the longitudinal spin Seebeck effect (LSSE) was investigated in ferrimagnetic NiFe2O4/Pt films from room temperature down to 50K base temperature.