Chemical Tuning Meets 2D Molecular Magnets

Abstract

Abstract2D magnets provoke a surge of interest in large anisotropy in reduced dimensions and are promising for next‐generation information technology where dynamic magnetic tuning is essential. Until recently, the crucial metal‐organic magnet Cr(pyz)2·xLiCl·yTHF with considerable high coercivity and high‐temperature magnetic order opens up a new platform to control magnetism in metal‐organic materials at room temperature. Here, an in–situ chemical tuning route is reported to realize the controllable transformation of low‐temperature magnetic order into room‐temperature hard magnetism in Cr(pyz)2·xLiCl·yTHF. The chemical tuning via electrochemical lithiation and solvation/desolvation exhibits continuously variable magnetic features from cryogenic magnetism to the room‐temperature optimum performance of coercivity (Hc) of 8500 Oe and energy product of 0.6 MGOe. Such chemically flexible tunability of room‐temperature magnetism is ascribed to the different degrees of lithiation and solvation that modify the stoichiometry and Cr‐pyrazine coordination framework. Furthermore, the additively manufactured hybrid magnets show air stability and electromagnetic induction, providing potential applications. The findings here suggest chemical tuning as a universal approach to control the anisotropy and magnetism of 2D hybrid magnets at room temperature, promising for data storage, magnetic refrigeration, and spintronics.

Stimuli-responsive magnetic materials: impact of spin and electronic modulation

“…is at the forefront of a broad range of technological device applications, for example, in memory devices, [1][2][3][4][5][6][7] sensors, [8][9][10][11][12] displays, [13][14][15] telecommunication, 16,17 etc. The addressability of the physical and/or chemical properties as a response to external stimuli involves two distinct states (termed bistability) distinguishable by the appearance, particularly crystal shape and color, [18][19][20][21][22] optical properties, 23,24 magnetization, 25,26 electrical polarization, [27][28][29][30][31] electrical resistance, [32][33][34][35][36] dielectric constant, [37][38][39][40][41] or other interesting physical properties. The fine-tuning of molecular bistability requires (i) suitable electronic attributes via judicious tuning of the ligand field strength, [42][43][44][45]…”

Origin of Weak Magnetic Coupling in a Dimanganese(II) Complex Bridged by the Tetrathiafulvalene-Tetrathiolate Radical

“…Molecule-based magnetic compounds, including discrete molecules and extended frameworks, have attracted significant attention in recent decades. − The tunability of molecular systems opens up possibilities for switchable magnetic properties via redox control, − irradiation, − or solvation/desolvation processes. − Furthermore, bottom-up synthetic approaches allow for systematic studies of structure–property relationships. − By controlling supramolecular interactions and combining the properties of different building blocks, stimuli-responsive or multifunctional magnetic materials have also been developed. − …”