Interaction Induced Magnetism in 2D Kagome Metal-Organic Frameworks on Substrates

<br/>Two dimmensional metal-organic frameworks (2D MOFs) have applications in functional electronics. Recent experiments [1] has discovered that dicyanoanthracene-copper, a MOF with a kagome lattice, has magnetic moments which arise due to strong electronic correlations between dicyanoanthracene molecules when on some substrates. Using a combination of density functional theory calculations and a Hubbard model, we investigate how the substrate influences magnetism in this 2D MOF systems. We cosider a large variety of substrates ranging from semiconducting to metallic, and show why this interaction-induced magnetism appears on some substrates but not others. We demonstrate that MOF-substrate coupling, charge transfer, and strain are essential key variables that control the magnetism in 2D MOFs. We further show how strain and electric fields can activate and deactivate magnetic phases in these materials. Our model presented here can be generalised to other MOFs and help design new functional devices.<br/><br/>[1] D. Kumar et al. Adv. Funct. Mater. 2021, 2106474.