Room Temperature Spin‐Dependent Transport in 2D Hofmann‐Type Single‐Layer Network

Abstract Room‐temperature magnetoresistance effect is reported on a 2D molecular‐based magnetic system using only one magnetic electrode, unlike the typical spin‐valve systems with two magnetic electrodes. Charge transport is measured using a scanning tunneling microscope on a molecular monolayer of a Hofmann‐type network consisting of a 2D [Pt(CN) ₄ Co] _x system. The layer is grown on a gold substrate by prior deposition of 4‐(ethyldisulfaneyl)pyridine (EtS‐Spy) so that the generated 4‐pyridinethiyl radical (pyS), anchored to gold through S, coordinates the Co ^II ions through the pyridine. The formation of the 2D [Pt(CN) ₄ Co] _x layer is verified by the presence of only bridging cyanide bands using vibrational spectroscopy. Employing a 4‐mercaptopyridine‐functionalized magnetic nickel tip, the reversal of the nickel magnetization direction results in the shutdown of the peak corresponding to the transport through the path formed by Ni‐Spy‐Co‐pyS‐Au, around 10 ⁻⁴ G ₀ of conductance. This assignment is confirmed by flicker noise analysis and Non‐Equilibrium Green's‐functions‐based density functional theory calculations, indicating that the 10 ⁻⁴ G ₀ conductance feature corresponds to through‐bond charge transport while the one observed at 2·10 ⁻⁵ G ₀ involves intermolecular contacts. This effect has been previously reported for magnetic molecules; however, its extension to 2D systems introduces an essential capability for applications in new spintronic devices.