Effects of diagonal strains and H-bond geometry in antiferroelectric squaric acid crystals

Abstract

The proton ordering model of the phase transition and physical properties of antiferroelectric crystals of squaric acid is modified by taking into account the influence of diagonal lattice strains and of the local geometry of hydrogen bonds, namely of the distance $\delta$ between the H-sites on a bond. Thermal expansion, the spontaneous strain ${\epsilon }_1-{\epsilon }_3$, and specific heat of squaric acid are well described by the proposed model. However, a consistent description of hydrostatic pressure influence on the transition temperature is possible only with further modifications of the model.

14 pages, 7 figures, 2 tables

References in corpus (2)

• Quantum Monte Carlo study of the formation of molecular polarizations and the antiferroelectric ordering in squaric acid crystals
• Mitsui model with diagonal strains: A unified description of external pressure effect and thermal expansion of Rochelle salt NaKC_4H_4O_6\cdot4H_2O

Cited by in corpus (3)

• Polarization rotation by external electric field in two-dimensional antiferroelectric squaric acid, H${}_2$C${}_4$O${}_4$
• Negative/positive electrocaloric effect in antiferroelectric squaric acid
• Influence of external field direction on polarization rotation in antiferroelectric squaric acid H${}_2$C${}_4$O${}_4$