Imprinting Ferromagnetism and Superconductivity in Single Atomic Layers of Molecular Superlattices

Abstract

Ferromagnetism and superconductivity are two antagonistic phenomena since ferromagnetic exchange fields tend to destroy singlet Cooper pairs. Reconciliation of these two competing phases has been achieved in vertically stacked heterostructures where these two orders are confined in different layers. However, controllable integration of these two phases in one atomic layer is a longstanding challenge. Here, an interlayer‐space‐confined chemical design (ICCD) is reported for the synthesis of dilute single‐atom‐doped TaS2 molecular superlattice, whereby ferromagnetism is observed in the superconducting TaS2 layers. The intercalation of 2H‐TaS2 crystal with bulky organic ammonium molecule expands its van der Waals gap for single‐atom doping via co‐intercalated cobalt ions, resulting in the formation of quasi‐monolayer Co‐doped TaS2 superlattices. Isolated Co atoms are decorated in the basal plane of the TaS2 via substituting the Ta atom or anchoring at a hollow site, wherein the orbital‐selected p–d hybridization between Co and neighboring Ta and S atoms induces local magnetic moments with strong ferromagnetic coupling. This ICCD approach can be applied to various metal ions, enabling the synthesis of a series of crystal‐size TaS2 molecular superlattices.

Science of 2.5 dimensional materials: paradigm shift of materials science toward future social innovation

“…(i) Intercalation of magnetic Co ions in the interlayer of TaS 2 with the assistant of TBAC molecules. Reproduced with permission from Wiley-VCH [ 89 ]. (j) TEM images of atomic layers of Ga, In, Sn formed at the interface between graphene and SiC substrate.…”

“…The use of 2D nanospace is not limited to BLG and FLG. For example, Li et al proposed ‘imprinting’ ferromagnetism by intercalating magnetic metals into layered TaS 2 ( Figure 7(i) ) [ 89 ]. Given that tetrabutylammonium chloride (TBAC) can be intercalated into a TaS 2 crystal, they facilitated the cointercalation of Co ions into TaS 2 layers by dissolving CoCl 2 in the TBAC solution.…”

Surface Functionalization for Magnetic Property Tuning of Nonmagnetic 2D Materials

“…SnSe 2 layers, inducing a high electron density 2D electron gas responsible for the superconducting state at low temperatures. Other studies have also investigated intercalation of magnetic entities [49] and incorporation of macromolecular nanosheets [50] into TaS 2 and TaS 2 -derivatives to further elucidate the interplay between superconductivity and magnetism in these hybrid systems.…”

Emerging field of few-layered intercalated 2D materials

“…142,143 However, an interlayer-space-conned chemical design (ICCD) is reported to integrate these two phases in one single-atom-doped TaS 2 layer, whereby ferromagnetism is observed in the superconducting TaS 2 layers. 141 The intercalation of bulky 2H-TaS 2 crystal with tetrabutylammonium chloride molecules expands its gap between layers, now suitable for single-atom doping via cointercalated Co ions, resulting in the formation of quasi-1L Co-doped TaS 2 superlattices (Fig. 19E).…”