High transport spin polarization in the van der Waals ferromagnet Fe${}_4$GeTe${}_2$

Abstract

The challenging task of scaling-down the size of the power saving electronic devices can be accomplished by exploiting the spin degree of freedom of the conduction electrons in van der Waals (vdW) spintronic architectures built with 2D materials. One of the key components of such a device is a near-room temperature 2D ferromagnet with good metallicity that can generate a highly spin-polarized electronic transport current. However, most of the known 2D ferromagnets have either a very low temperature ordering, poor conductivity, or low spin polarization. In this context, the Fe${}_n$GeTe${}_2$ (with $n\ge 3$) family of ferromagnets stand out due to their near-room temperature ferromagnetism and good metallicity. We have performed spin-resolved Andreev reflection spectroscopy on Fe${}_4$GeTe${}_2$ ($T_{Curie}\sim$ 273 K) and demonstrated that the ferromagnet is capable of generating a very high transport spin polarization, exceeding 50$\%$. This makes Fe${}_4$GeTe${}_2$ a strong candidate for application in all-vdW power-saving spintronic devices.

Accepted for publication in Physical Review B

References in corpus (6)

• Van der Waals heterostructures for spintronics and opto-spintronics
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• Evidence of gap anisotropy in superconducting YNi2B2C using directional point contact spectroscopy
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Cited by in corpus (3)

• Disentangling the unusual magnetic anisotropy of the near-room-temperature ferromagnet Fe${}_4$GeTe${}_2$
• Factors affecting the topological Hall effect in strongly correlated layered magnets: spin of the magnetic atoms, polar and azimuthal angle subtended by the spin texture
• New perspective on symmetry breaking in a clean antiferromagnetic chain: Spin-selective transport and NDR phenomenon