Quantum transport in oxidized Ni nanocontacts under mechanical strain

Razavifar, Zahra; Saffarzadeh, Alireza; Palacios, J. J.

doi:10.1103/physrevb.101.235442

Cited by 3 publications

(1 citation statement)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the last two decades, a comprehensive study has been made in atomic and molecular junctions based on conventional ferromagnetic electrodes ( e.g ., Ni, Co, and Fe). However, electron transport in these ferromagnets is dominated by almost no spin-polarized s bands, leading to limited spin-polarized conduction in related nanoscale devices. , The insertion of a small gas molecule in the formation of nanocontacts shows a significant improvement of SP due to the associated orbital-symmetry matching at the interfaces; however, it is rather sensitive to geometrical details at the interfaces. − Spin-polarized scanning tunneling microscopy (STM) is often used to locally probe the MR effect in ferromagnetic substrates involving adsorbed adatoms or molecules. − On the other hand, from a theoretical point of view, the first-principles quantum transport simulations have also been widely used to explore various possible single-molecule junctions. − The measured MR in these experimental and theoretical studies are found to be about several tens of percent, indicating a partially spin-polarized transport, thus deterring the development of nanoscale spintronics.…”

Section: Introductionmentioning

confidence: 99%

Robust Giant Magnetoresistance in 2D Van der Waals Molecular Magnetic Tunnel Junctions

Frauenheim

2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The spin transport across a zero-dimensional (0D) single-molecule sandwiched by two-dimensional (2D) van der Waals (vdW) ferromagnetic electrodes may open vast opportunities to create novel mixed-dimensional spintronics devices. However, this remains unexplored yet. Inspired by the recent discovery of 2D intrinsic ferromagnets Fe3GeTe2, using first-principles spin transport calculations, we show that single-molecule junctions based on Fe3GeTe2 can yield perfect spin filtering and a significant magnetoresistance (MR) of up to ∼6075%. This remarkable MR is more than 2 orders of magnitude higher than the MR obtained for the corresponding junctions with conventional ferromagnetic metals (e.g., Ni, Fe, and Co). We demonstrate the results of two representative examples that are feasible in the experiments: (i) A benzene or (ii) bezenedithiol (BDT) connected either through a scanning tunneling microscope or break-junction setups. We find that the conductance of BDT junctions is more than 10 times larger than that of the benzene junction due to a much stronger hybridization effect at the molecule–metal interfaces. The key mechanism of the perfect spin filtering and large MR in single-molecule junctions is mainly determined by the intrinsic properties of Fe3GeTe2 electrodes, while the actual conductance is determined by the hybridization strength of the majority spin channel at the molecule–metal interfaces. It is also predicted that the perfect spin filtering and the remarkably huge MR are highly insensitive to structural variations, interface defects, and stacking orders of the electrodes. Our results provide important insights for expanding molecular spintronics platforms from conventional ferromagnetic metals to new 2D vdw magnets.

show abstract