Near‐Room‐Temperature Magnetoelectric Coupling via Spin Crossover in an Iron(II) Complex

• Published in: Angewandte Chemie (International ed.) Vol. 61; no. 52; pp. e202214335 - n/a
• Main Authors: Owczarek, Magdalena, Lee, Minseong, Liu, Shuanglong, Blake, Ella R., Taylor, Chloe S., Newman, Georgia A., Eckert, James C., Leal, Juan H., Semelsberger, Troy A., Cheng, Hai‐Ping, Nie, Wanyi, Zapf, Vivien S.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 23.12.2022; Wiley Blackwell (John Wiley & Sons); John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Coupling; Coupling (molecular); Crossovers; Cryogenic temperature; Dielectric constant; Dipole moments; Electric polarization; Electrical properties; High Magnetic Field Science; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Iron; Jahn-Teller effect; Magnetic fields; Magnetic Properties; Magnetoelectric Coupling; Molecular Magnet; Polarization; Room temperature; Spin Crossover; Structural Phase Transition; Magnetoelectric Coupling; Molecular Magnet; Structural Phase Transition; Spin Crossover; Magnetic Properties
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202214335

Magnetoelectric coupling is achieved near room temperature in a spin crossover FeII molecule‐based compound, [Fe(1bpp)2](BF4)2. Large atomic displacements resulting from Jahn–Teller distortions induce a change in the molecule dipole moment when switching between high‐spin and low‐spin states leading to a step‐wise change in the electric polarization and dielectric constant. For temperatures in the region of bistability, the changes in magnetic and electrical properties are induced with a remarkably low magnetic field of 3 T. This result represents a successful expansion of magnetoelectric spin crossovers towards ambient conditions. Moreover, the observed 0.3–0.4 mC m−2 changes in the H‐induced electric polarization suggest that the high strength of the coupling obtained via this route is accessible not just at cryogenic temperatures but also near room temperature, a feature that is especially appealing in the light of practical applications. Magnetoelectric coupling is achieved near room temperature in a spin crossover FeII molecule‐based compound. The coupling is realized through the interplay of structural, magnetic, and electrical changes that allows the spin crossover to be driven by a remarkably low magnetic field of 3 T.