Designing a mechanically driven spin-crossover molecular switch via organic embedding. Issue 17 (1st August 2021)

• Record Type: Journal Article
• Authors: Bhandary, Sumanta; Tomczak, Jan M.; Valli, Angelo
• Is Part Of: Nanoscale advances. Volume 3:Issue 17(2021)
• Page Start: 4990
• Page End: 4995
• Publication Date: 2021-08-01
• Subjects: 620.5
• DOI: 10.1039/d1na00407g
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : A strain-induced spin-crossover in iron porphyrin is made exploitable through robust organic embedding via graphene nano-ribbons. Abstract : Among spin-crossover complexes, Fe–porphyrin (FeP) stands out for molecular spintronic applications: an intricate, yet favourable balance between ligand fields, charge transfer, and the Coulomb interaction makes FeP highly manipulable, while its planar structure facilitates device integration. Here, we theoretically design a mechanical spin-switch device in which external strain triggers the intrinsic magneto-structural coupling of FeP through a purely organic embedding. Exploiting the chemical compatibility and stretchability of graphene nanoribbon electrodes, we overcome common reliability and reproducibility issues of conventional inorganic setups. The competition between the Coulomb interaction and distortion-induced changes in ligand fields requires methodologies beyond the state-of-the-art: combining density functional theory with many-body techniques, we demonstrate experimentally feasible tensile strain to trigger a low-spin ( S = 1) to high-spin ( S = 2) crossover. Concomitantly, the current through the device toggles by over an order of magnitude, adding a fully planar mechanical current-switch unit to the panoply of molecular spintronics.