%0 Journal Article
%A Bermúdez García, Juan Manuel
%A García Fernández, Alberto
%A Andrada Chacón, Adrián
%A Sánchez Benítez, Francisco Javier
%A Ren, Wei 
%A Hu, Shunbo 
%A Gu, Teng 
%A Xiang, Hongjun 
%A Biczysko, Malgorzata 
%A Castro-García, Socorro 
%A Sánchez-Andújar, Manuel 
%A Stroppa, Alessandro 
%A Señarís-Rodríguez, María Antonia 
%T Pressure-induced reversible framework rearrangement and increased polarization in the polar [NH<sub>4</sub>][Cd(HCOO)<sub>3</sub>] hybrid perovskite
%D 2019
%@ 2052-1553
%U https://hdl.handle.net/20.500.14352/116511
%X In this work, we study the structural changes of the polar [NH4][Cd(HCOO)3] hybrid perovskite under external hydrostatic pressure. We report a reversible framework rearrangement as a function of pressure characterized by: (i) a gradual modification of one formate ligand, which changes its coordination mode from a bridging syn–anti mode at atmospheric pressure (LP-phase) to a chelating-anti mode at high pressure (HP-phase) and (ii) a change in the coordination of the Cd2+ cations from six-coordinated (LPphase) to hepta-coordinated (HP-phase). Very interestingly, this unprecedented framework arrangement displays a large electrical polarization. For instance, the polarization value observed at p = 17.7 GPa is about four times the polarization at atmospheric pressure. Therefore, we report that the external pressure induces a novel framework rearrangement in the polar [NH4][Cd(HCOO)3] hybrid perovskite withenhanced electrical polarization. This structure–property relationship offers new insights for designing novel ferroelectric materials based on pressure-responsive hybrid perovskite materials.
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