High-performance Pyroelectric Property Accompanied by Spin Crossover in a Single Crystal of Fe(II)  Complex

Angew Chem Int Ed Engl. 2024 Apr 8:e202405514. doi: 10.1002/anie.202405514. Online ahead of print.ABSTRACTPyroelectric materials hold significant potential for energy harvesting, sensing, and imaging applications. However, achieving high-performance pyroelectricity across a wide temperature range near room temperature remains a significant challenge. Herein, we demonstrate a single crystal of Fe(II) spin-crossover compound shows remarkable pyroelectric properties accompanied by a thermally controlled spin transition. In this material, the uniaxial alignment of polar molecules results in a polarization of the lattice. As the molecular geometry is modulated during a gradual spin transition, the polar axis experiences a colossal thermal expansion with a coefficient of 796 × 10-6 K-1. Consequently, the material's polarization undergoes significant modulation as a secondary pyroelectric effect. The considerable shift in polarization (pyroelectric coefficient, p = 3.7~22 nC K-1cm-2), coupled with a low dielectric constant (ε' = 4.4~5.4) over a remarkably wide temperature range of 298 to 400 K, suggests this material is a high-performance pyroelectric. The demonstration of pyroelectricity combined with magnetic switching in this study will inspire further investigations in the field of molecular electronics and magnetism.PMID:38584585 | DOI:10.1002/anie.202405514

Source: Angewandte Chemie - April 8, 2024 Category: Chemistry Authors: Chengdong Liu Yun Li Zheng Tang Kai-Ge Gao Jing Xie Jun Tao Zi-Shuo Yao Source Type: research