Strong In-Plane Magnetization and Spin Polarization in (Co0.15Fe0.85)5GeTe2/Graphene van der Waals Heterostructure Spin-Valve at Room Temperature
Artikel i vetenskaplig tidskrift, 2023

Van der Waals (vdW) magnets are promising, because of their tunable magnetic properties with doping or alloy composition, where the strength of magnetic interactions, their symmetry, and magnetic anisotropy can be tuned according to the desired application. However, so far, most of the vdW magnet-based spintronic devices have been limited to cryogenic temperatures with magnetic anisotropies favoring out-of-plane or canted orientation of the magnetization. Here, we report beyond room-temperature lateral spin-valve devices with strong in-plane magnetization and spin polarization of the vdW ferromagnet (Co0.15Fe0.85)5GeTe2 (CFGT) in heterostructures with graphene. Density functional theory (DFT) calculations show that the magnitude of the anisotropy depends on the Co concentration and is caused by the substitution of Co in the outermost Fe layer. Magnetization measurements reveal the above room-temperature ferromagnetism in CFGT and clear remanence at room temperature. Heterostructures consisting of CFGT nanolayers and graphene were used to experimentally realize basic building blocks for spin valve devices, such as efficient spin injection and detection. Further analysis of spin transport and Hanle spin precession measurements reveals a strong in-plane magnetization with negative spin polarization at the interface with graphene, which is supported by the calculated spin-polarized density of states of CFGT. The in-plane magnetization of CFGT at room temperature proves its usefulness in graphene lateral spin-valve devices, thus revealing its potential application in spintronic technologies.

2D magnets

in-plane magnetization

spin-valve

van der Waals heterostructures

spin polarization

van der Waals magnet

graphene

Författare

Roselle Ngaloy

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Bing Zhao

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Soheil Ershadrad

Uppsala universitet

Rahul Gupta

Uppsala universitet

Masoumeh Davoudiniya

Uppsala universitet

Lakhan Bainsla

Indian Institute of Technology

Lars Sjöström

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Anamul Md Hoque

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

Alexei Kalaboukhov

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

P Svedlindh

Uppsala universitet

Biplab Sanyal

Uppsala universitet

Saroj Prasad Dash

Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik

ACS Nano

1936-0851 (ISSN) 1936-086X (eISSN)

Vol. In Press

Graphene Core Project 3 (Graphene Flagship)

Europeiska kommissionen (EU) (EC/H2020/881603), 2020-04-01 -- 2023-03-31.

2D Heterostructure Non-volatile Spin Memory Technology (2DSPIN-TECH)

Europeiska kommissionen (EU) (EC/HE/101135853), 2023-12-01 -- 2026-11-30.

Topologi och magnetism i nya kvantmaterial

Vetenskapsrådet (VR) (2018-07046), 2020-01-01 -- 2021-12-31.

Ämneskategorier

Annan fysik

Den kondenserade materiens fysik

DOI

10.1021/acsnano.3c07462

PubMed

38330915

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Senast uppdaterat

2024-05-29