Galvanic intercalation of molecular cations into van der Waals materials

TL;DR

This paper presents a simple galvanic method for intercalating various molecules into van der Waals materials under ambient conditions, enabling the tuning of magnetic and superconducting properties in atomically thin quantum materials.

Contribution

The authors introduce a broadly applicable galvanic intercalation technique that preserves crystalline quality and enables in-situ intercalation of molecules into diverse vdW materials.

Findings

Achieved intercalation of nine vdW materials with different molecules.

Induced magnetic transition from antiferromagnetic to ferrimagnetic in {1}-RuCl3.

Enhanced superconducting transition temperature in 2H-TaS2.

Abstract

The intercalation of molecular species between the layers of van der Waals (vdW) crystals is a powerful approach to combine the remarkable physical properties of vdW materials with the chemical versatility of organic molecules. However, the full transformative potential of molecular intercalation remains underexplored, largely due to the lack of simple, broadly applicable methods that preserve high crystalline quality down to the few-layer limit. Here, we introduce a simple galvanic approach to intercalate different molecules into various vdW materials under ambient conditions, leveraging the low reduction potential of selected metals. We employ our method, which is particularly well-suited for the in-situ intercalation of few-layer-thick crystals, to intercalate nine vdW materials, including magnets and superconductors, with molecules ranging from conventional alkylammonium ions to metallorganic and bio-inspired chiral cations. Notably, intercalation leads to an unprecedented transition from antiferromagnetic to ferrimagnetic ordering in {\alpha}-RuCl3 and to a molecule-dependent enhancement of the superconducting transition in 2H-TaS2. These results establish our approach as a versatile technique for engineering atomically thin quantum materials and heterostructures, unlocking the transformative effects of molecular intercalation.