Journal
JOURNAL OF PHYSICAL CHEMISTRY B
Volume 115, Issue 27, Pages 8755-8762Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp202192k
Keywords
-
Categories
Funding
- Polish Ministry of Science and Higher Education [N N202 032240]
Ask authors/readers for more resources
Dielectric, calorimetric, and X-ray diffraction methods have been employed to characterize the crystals of guanidinium tetrafluoroborate and guanidinium perchlorate, both built of two-dimensional honeycomb hydrogen-bonded sheets. The room-temperature ferroelectricity of these isosymmetric complexes (space group R3m) has been evidenced by the polarization switching in an external electric field and pyroelectric effect. The analysis of structural data as a function of temperature showed that the high values of spontaneous polarization of about 8.5 mu C cm(-2) originate mainly from the ionic displacements, while the exceptional thermally induced increase of polarization is related with the apparent weakening of the N-H center dot center dot center dot F/N-H center dot center dot center dot O hydrogen bonds at elevated temperatures. An excellent correlation between the donor-acceptor distance and the relative displacement of the ions in the crystal lattice along the polar direction has been found. The huge entropy change at the two-closely spaced high-temperature phase transitions in guanidinium perchlorate, together with the large crystal polarization, suggest a large electrocaloric effect, the property strongly desired for solid-state cooling applications.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available