Exfoliation and van der Waals heterostructure assembly of intercalated ferromagnet Cr1/3TaS2

TL;DR

This paper demonstrates the exfoliation of intercalated ferromagnetic Cr1/3TaS2, its magnetic properties preserved at thin layers, and the assembly of heterostructures with Fe1/4TaS2 showing tunnel magnetoresistance, advancing 2D spintronics.

Contribution

It introduces a method to exfoliate intercalated ferromagnetic materials and assemble vdW heterostructures with functional magnetic properties.

Findings

Exfoliated Cr1/3TaS2 retains bulk ferromagnetic properties.

Heterostructures exhibit tunnel magnetoresistance.

Demonstrated spin injection potential in vdW ferromagnetic junctions.

Abstract

Ferromagnetic van der Waals (vdW) materials are in demand for spintronic devices with all-two-dimensional-materials heterostructures. Here, we demonstrate mechanical exfoliation of magnetic-atom-intercalated transition metal dichalcogenide Cr1/3TaS2 from its bulk crystal; previously such intercalated materials were thought difficult to exfoliate. Magnetotransport in exfoliated tens-of-nanometres-thick flakes revealed ferromagnetic ordering below its Curie temperature TC ~ 110 K as well as strong in-plane magnetic anisotropy; these are identical to its bulk properties. Further, van der Waals heterostructure assembly of Cr1/3TaS2 with another intercalated ferromagnet Fe1/4TaS2 is demonstrated using a dry-transfer method. The fabricated heterojunction composed of Cr1/3TaS2 and Fe1/4TaS2 with a native Ta2O5 oxide tunnel barrier in between exhibits tunnel magnetoresistance (TMR), revealing possible spin injection and detection with these exfoliatable ferromagnetic materials through the vdW junction.