Publications Repository - Gdańsk University of Technology

Two-dimensional (2D) van der Waals (vdW) magnetic 3d-transition metal trihalides are a new class of functional materials showing exotic physical properties useful for spintronic and memory storage applications. In this article, we report the synthesis and electromagnetic characterization of single-crystalline vanadium trichloride, VCl 3 , a novel 2D layered vdW Mott insulator, which has a rhombohedral structure (R3, No. 148) at room temperature. VCl 3 undergoes a structural phase transition at 103 K and a subsequent antiferromagnetic transition at 21.8 K. Combining core levels and valence bands x-ray photoemission spectroscopy (XPS) with first-principles density functional theory (DFT) calculations, we demonstrate the Mott Hubbard insulating nature of VCl 3 and the existence of electron small 2D magnetic polarons localized on V atom sites by V-Cl bond relaxation. The polarons strongly affect the electromagnetic properties of VCl 3 promoting the occupation of dispersion-less spin-polarized V-3d a1g states and band inversion with e′ g states. Within the polaronic scenario, it is possible to reconcile different experimental evidences on vanadium trihalides, suggesting that also VI 3 hosts polarons. Our results highlight the complex physical behavior of this class of crystals determined by charge trapping, lattice distortions, correlation effects, mixed valence states, and magnetic states.

Authors

• Dario Mastrippolito,
• Luigi Camerano,
• Hanna Świątek link open in new tab ,
• Břetislav Šmíd,
• prof. dr hab. inż. Tomasz Klimczuk link open in new tab ,
• Luca Ottaviano,
• Gianni Profeta