Emerged Metallicity in Molecular Ferromagnetic Wires

Abstract

Supramolecular engineering bridges molecular assembly with macromolecular charge-transfer salts, promising the design to construct supramolecular architectures that integrate cooperative properties difficult or impossible to find in conventional lattices. Here, we report the crystal engineering design and kinetic growth of one-dimensional supramolecular wires composed of bis(ethylenedithio)tetrathiafulvalene (ET + ) cation and polymeric Cu[N(CN) 2 ] 2 − anion. A bulk ferromagnetic order is discovered for filling up the gap where strong ferromagnetism is missing in such ET molecule-based charge-transfer salts. Metallicity is induced by electric current from the semiconducting wire, which is attributed to strain effect by tuning its close molecular contact. This structural feature is evidenced through the combination of various mechanistic spectroscopic studies. Electric dipole is established from the close molecular contacts and is suggestive to stabilize ferromagnetic spin interaction through anions bridging spin sites. The breakthrough shown here provides a pathway to explore low-dimensional supramolecular materials exhibiting strong electron correlation, metallicity, and ferromagnetism.

Controlled Growth and Chemical Engineering of FeSe‐Based Superconducting Films

“…Superconducting materials can always be divided into a specific category according to their common base of DOI: 10.1002/apxr.202200058 structural unit, like cuprates, ironbased, nickel-based, and organic superconductors, [9][10][11][12] exhibiting the abundant physical properties of a common origination. Starting from a common structural unit of copper oxide (CuO 2 ), [13,14] iron pnictide/chalcogenide/sulfide (FeAs, FeSe, or FeS), [15,16] nickel oxide (NiO 2 ), [17,18] or organic molecules, [19,20] a large superconducting material family has been designed and synthesized. The structurally simplest iron-based superconductor, the binary compound iron selenide (FeSe), [21] is one of the promising candidates for exploring materials design and interfacial engineering.…”