Corpus ID: 235694376

Comment on Improper molecular ferroelectrics with simultaneous ultrahigh pyroelectricity and figures of merit by Li et al

@inproceedings{Szafranski2021CommentOI,
  title={Comment on Improper molecular ferroelectrics with simultaneous ultrahigh pyroelectricity and figures of merit by Li et al},
  author={Marek Szafra'nski and Andrzej Katrusiak},
  year={2021}
}
Li et al. (Science Advances, 29 January, p. eabe3068) claim the discovery of two improper ferroelectrics, dabcoHClO4 and dabcoHBF4 (dabco = 1,4-diazabicyclo[2.2.2]octane), and that these materials exhibit superior pyroelectric figures of merit. This information is misleading due to the fundamental methodological errors and false conclusions, not to mention that these ferroelectrics were reported over 20 years ago. They are proper ferroelectrics, for which the spontaneous polarization is the… Expand

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SHOWING 1-10 OF 13 REFERENCES
Improper molecular ferroelectrics with simultaneous ultrahigh pyroelectricity and figures of merit
TLDR
The first-principles and thermodynamic calculations show that the strong coupling between the order parameters, i.e., the rotation angle of anions and polarization, is responsible for the colossal pyroelectric coefficient of the molecular ferroelectrics. Expand
Ultrafast Polarization Switching in a Biaxial Molecular Ferroelectric Thin Film: [Hdabco]ClO4.
TLDR
This work presents a biaxial molecular ferroelectric thin film of [Hdabco]ClO4 ( dabco = 1,4-diazabicyclo[2.2]octane) (1), where a perfect ferro electric hysteresis loop can be observed even at 10 kHz, and provides direct experimental proof that 180° and non-180° ferroelastic switching are both realized. Expand
New Polar Phases of 1,4-Diazabicyclo[2.2.2]octane Perchlorate, An NH+···N Hydrogen-Bonded Ferroelectric
Exceptionally rich diagram of ten phases, I–X, has been revealed for ferroelectric 1,4-diazabicyclo[2.2.2]octane perchlorate, [C6H13N2]+ClO4–, dabcoHClO4. Pressure- and temperature-inducedExpand
Pressure–Temperature Phase Diagrams and Transition Mechanisms of Hybrid Organic–Inorganic NH···N Bonded Ferroelectrics
The ferroelectric–paraelectric transitions of 1,4-diazabicyclo[2.2.2]octane (dabco) tetrafluoroborate (dabcoHBF4) and perchlorate (dabcoHClO4), between their phases II (orthorhombic space groupExpand
Anomalous protonic-glass evolution from ordered phase in NH...N hydrogen-bonded dabcoHBF4 ferroelectric.
Dielectric properties, spontaneous polarization, and phase transitions of the NH+...N bonded ferroelectric dabcoHBF4 (i.e., 1,4-diazabicyclo[2.2.2]octane tetrafluoroborate, [C6H13N2]+ BF4-) have beenExpand
Improper Ferroelectric Phase Transitions
Recent progress in the understanding of the improper ferroelectric phase transitions is reviewed. The phase transition in ammonium Rochelle salt is discussed from the symmetry point of view. TheExpand
Katrusiak, Pressure-temperature phase diagrams and transition mechanism of hybrid organic-inorganic NH···N bonded ferroelectrics
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