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arXiv · 2010.04453

Electronic and magnetic properties of $\alpha$-FeGe$_2$ films embedded in vertical spin valve devices

Dietmar Czubak·Samuel Gaucher·Lars Oppermann·Jens Herfort·Klaus Zollner·Jaroslav Fabian·Holger T. Grahn·Manfred Ramsteiner
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Abstract

We studied metastable $\alpha$-FeGe$_2$, a novel layered tetragonal material, embedded as a spacer layer in spin valve structures with ferromagnetic Fe$_3$Si and Co$_2$FeSi electrodes. For both types of electrodes, spin valve operation is demonstrated with a metallic transport behavior of the $\alpha$-FeGe$_2$ spacer layer. The spin valve signals are found to increase both with temperature and spacer thickness, which is discussed in terms of a decreasing magnetic coupling strength between the ferromagnetic bottom and top electrodes. The temperature-dependent resistances of the spin valve structures exhibit characteristic features, which are explained by ferromagnetic phase transitions between 55 and 110~K. The metallic transport characteristics as well as the low-temperature ferromagnetism are found to be consistent with the results of first-principles calculations.

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Dietmar Czubak, Samuel Gaucher, Lars Oppermann, Jens Herfort, Klaus Zollner, Jaroslav Fabian, Holger T. Grahn, Manfred Ramsteiner. 2020-10-09. Electronic and magnetic properties of $\alpha$-FeGe$_2$ films embedded in vertical spin valve devices. https://arxiv.org/abs/2010.04453

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