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Indexed by:Journal Papers

Date of Publication:2020-12-29

Journal:APL MATERIALS

Volume:8

Issue:7

ISSN No.:2166-532X

Abstract:As a new class of single-molecule magnets, two-coordinate complexes of open-shell transition metals are comparatively rare and have attracted interest due to their high degree of coordinative unsaturation. However, the dynamic distortion associated with the low coordination number of the metal center hinders the applications of high-density information storage, quantum computing, and spintronics. Here, we propose a series of stable 2D metal-organic frameworks constructed by ideal (1, 3, 5)-benzenetricarbonitrile (TCB) molecules and 5d transition metals (Hf, Ta, W, Re, Os, and Ir) with a highly symmetrical ligand field and rigid pi conjugated framework. Among them, TCB-Re exhibits intrinsic ferromagnetic ordering with a considerably large magnetic anisotropic energy (MAE) of 19 meV/atom and high Curie temperature (T-C) of 613 K. Under biaxial strain, diverse magnetic states (such as ferromagnetic, paramagnetic, and antiferromagnetic states) can be achieved in TCB-Re by the complicated competition between the in-planed-p(x/y)-dand out-of-planed-p(z)-dsuperexchange interactions. At a small compressive strain of 0.5%, the MAE for perpendicular magnetization increases substantially to 120 meV/atom; meanwhile, the magnetization andT(C)above room temperature are well retained. Our results not only extend two-coordinate transition metal complexes to continuous 2D organic magnets but also demonstrate an effective method of strain engineering for manipulating the spin state and MAE.