Probing the Structure and Dynamics of the [NH4]M(HCO2)3 Ferroelectric Phases: Dielectric Relaxation through Orientational Disorder† DOI Creative Commons
Thomas J. Hitchings, Helen M. Wickins,

Lydia G. Burley

et al.

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 8, 2025

Comprehensive Summary Neutron diffraction studies of the low‐temperature relaxor ferroelectric phases [NH 4 ]M(HCO 2 ) 3 , where M = Mn 2+ and Zn show that a third NH + cations remain subtly structurally disordered to low temperature. All within channels are well separated from each other, with significant hydrogen bonds only anionic M(HCO framework. Complementary dynamics using H solid state NMR quasielastic neutron scattering indicate rotational motion in both paraelectric phases, which evolves gradually increasing temperature no abrupt change at phase transition. Nudged elastic band calculations suggest activation barrier for flipping between “up” “down” orientations is phase, primarily interacting framework rather than neighbouring cations. It likely this responsible scrambling cation orientation locally phase. We propose disorder, same basic active above below transition, induces dielectric relaxation these materials. This suggests orientational disorder may be an effective substitution compositional commonly associated ferroelectrics molecular

Language: Английский

Probing the Structure and Dynamics of the [NH4]M(HCO2)3 Ferroelectric Phases: Dielectric Relaxation through Orientational Disorder† DOI Creative Commons
Thomas J. Hitchings, Helen M. Wickins,

Lydia G. Burley

et al.

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 8, 2025

Comprehensive Summary Neutron diffraction studies of the low‐temperature relaxor ferroelectric phases [NH 4 ]M(HCO 2 ) 3 , where M = Mn 2+ and Zn show that a third NH + cations remain subtly structurally disordered to low temperature. All within channels are well separated from each other, with significant hydrogen bonds only anionic M(HCO framework. Complementary dynamics using H solid state NMR quasielastic neutron scattering indicate rotational motion in both paraelectric phases, which evolves gradually increasing temperature no abrupt change at phase transition. Nudged elastic band calculations suggest activation barrier for flipping between “up” “down” orientations is phase, primarily interacting framework rather than neighbouring cations. It likely this responsible scrambling cation orientation locally phase. We propose disorder, same basic active above below transition, induces dielectric relaxation these materials. This suggests orientational disorder may be an effective substitution compositional commonly associated ferroelectrics molecular

Language: Английский

Citations

0