Enhancement of the Magnetoelectric Effect Using the Dynamic Jahn-Teller Effect in a Transition-Metal Complex

Magnetoelectricity Enhanced by Electron Redistribution in a Spin Crossover [FeCo] Complex

“…Magnetoelectric (ME) materials, which exhibit polarization switching in response to a magnetic field or magnetization switching in response to an electric field, offer a variety of potential applications, particularly the next-generation ME memory devices with higher data density and faster reading speed. − Extensive investigations over the last two decades have proven that some multiferroic inorganic oxides, such as LnMnO 3 , LnMn 2 O 5 , and CuB 2 O 4 systems (Ln = lanthanide ions), − exhibit magnetic field-induced polarization change induced by, for example, the Katsura–Nagaosa–Balatsky mechanism, exchange striction, or spin-dependent p–d hybridization effects. − Motivated by the demand of device miniaturization, recently, researchers have increasingly focused their attention on the ME effects in molecular materials. Among many such efforts, ME coupling induced by the spin crossover (SCO) phenomenon has piqued the curiosity of physicists and chemists, and corresponding mechanisms, e.g., shift in transition temperature induced by the Zeeman effect − and suppression of dipole moment fluctuation induced by the freezing of Jahn–Teller distortion, have been proposed. , However, the polarization change induced by the magnetic field in such systems is still small, and the current record, ca. 0.12 μC cm –2 in a Mn­(III) SCO complex, is significantly lower than the practical application threshold in ME memory devices (1 μC cm –2 ). ,− Rationally enhancing the polarization change in SCO systems still remains a formidable challenge.…”

“…Among many such efforts, ME coupling induced by the spin crossover (SCO) phenomenon has piqued the curiosity of physicists and chemists, and corresponding mechanisms, e.g., shift in transition temperature induced by the Zeeman effect 15−18 and suppression of dipole moment fluctuation induced by the freezing of Jahn−Teller distortion, have been proposed. 19,20 However, the polarization change induced by the magnetic field in such systems is still small, 17 and the current record, ca. 0.12 μC cm −2 in a Mn(III) SCO complex, 16 is significantly lower than the practical application threshold in ME memory devices (1 μC cm −2 ).…”