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Abstract Van der Waals (vdW) materials are an indispensable part of functional device technology due to their versatile physical properties and ease of exfoliating to the low‐dimensional limit. Among all the compounds investigated so far, the search for magnetic vdW materials has intensified in recent years, fueled by the realization of magnetism in 2D. However, metallic magnetic vdW systems are still uncommon. In addition, they rarely host high‐mobility charge carriers, which is an essential requirement for high‐speed electronic applications. Another shortcoming of 2D magnets is that they are highly air sensitive. Using chemical reasoning, TaCo2Te2is introduced as an air‐stable, high‐mobility, magnetic vdW material. It has a layered structure, which consists of Peierls distorted Co chains and a large vdW gap between the layers. It is found that the bulk crystals can be easily exfoliated and the obtained thin flakes are robust to ambient conditions after 4 months of monitoring using an optical microscope. Signatures of canted antiferromagntic behavior are also observed at low‐temperature. TaCo2Te2shows a metallic character and a large, nonsaturating, anisotropic magnetoresistance. Furthermore, the Hall data and quantum oscillation measurements reveal the presence of both electron‐ and hole‐type carriers and their high mobility.
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Precision Synthesis of a Single Chain Polymorph of a 2D Solid within Single‐Walled Carbon Nanotubes
Abstract The discovery and synthesis of atomically precise low‐dimensional inorganic materials have led to numerous unusual structural motifs and nascent physical properties. However, access to low‐dimensional van der Waals (vdW)‐bound analogs of bulk crystals is often limited by chemical considerations arising from structural factors like atomic radii, bonding or coordination, and electronegativity. Using single‐walled carbon nanotubes (SWCNTs) as confinement templates, we demonstrate the synthesis of a short‐wave infrared‐absorbing quasi‐1D (q‐1D) chain polymorph of Sb2Te3([Sb4Te6]n) that is structurally and electronically distinct from its 2D counterpart. It is found that the q‐1D chain polymorph has both three‐ and five‐coordinate Sb atoms covalently bonded to Te and is thermodynamically stabilized by the electrostatic interaction between the encapsulated chain and the model SWCNT. The complementary experimental and computational results demonstrate the synthetic advantage of vdW nanotube confinement in the discovery of low‐dimensional polytypes with drastically altered physical properties and potential applications in energy conversion processes.
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- Award ID(s):
- 2340918
- PAR ID:
- 10641007
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 37
- Issue:
- 28
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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