Wydział Chemii

Michał Chański

Agata Białońska

Ryszard Jakubas

Magdalena Rok

Jan K. Zaręba

Rafał Janicki

Piotr Durlak

Anna Piecha-Bisiorek

2023

Journal of Physical Chemistry Letters

14

4524-4531

10.1021/acs.jpclett.3c00924

Naukowa

Angielski

Artykuł

Halobismuthates(III) and haloantimonates(III) with the R₃MX₆ chemical composition create a new and broadly unexplored class of ferroelectric compounds. In this paper, we report the haloantimonate(III) ferroelectric comprising an aromatic (1,2,4-triazolium) cation, i.e., (C₂N₃H₄)₃[SbBr₆] (TBA). Temperature-resolved structural and spectroscopic studies indicate that TBA undergoes two solid–solid phase transitions between tetragonal [P4₂/m (I)] and monoclinic [P2₁/n (II) and P2₁ (III)] phases. TBA experiences a paraelectric–ferroelectric phase transition at 271/268 K (II–III) driven by “order–disorder” and “displacive” molecular mechanisms. The ferroelectric properties of phase III have been confirmed by hysteresis loop measurement, and additionally, the acentric order has been further supported by second-harmonic generation measurements. Insight into the molecular origins of the ferroelectric polarization was provided by periodic ab initio calculations using the Berry phase approach at the density functional theory (DFT-D3) method level employed for calculations of spontaneous polarization.

Anions, Bromine, Cations, Phase transitions, Polarization

CC-BY

http://doi.org/10.1021/acs.jpclett.3c00924

https://www.acs.org/content/acs/en.html