Polarization rotation by external electric field in two-dimensional antiferroelectric squaric acid, H${}_2$C${}_4$O${}_4$

Abstract

A pseudospin model for description of the influence of the electric field, confined to the plane of sublattice polarization, on the two-dimensional squaric acid antiferroelectrics is developed. The system behavior is analyzed in terms of the parameters of ferroelectric and antiferroelectric ordering, as well as the non-collinearity angle $\theta$, which is the angle between sublattice polarizations. The temperature-electric field $T-E_1$ phase diagram is constructed. Most of the field-induced transitions are found to be associated with polarization rotation. The observed phases include the collinear ferroelectric and non-collinear ferrielectric with almost antiparallel and perpendicular polarizations of the sublattices, respectively. The diagram also contains two regions, where the non-collinearity angle varies continuously between, nominally, 0 and 90${}^{\circ }$ and between 90${}^{\circ }$ and 180${}^{\circ }$. The first and second order transition lines, supercritical lines, critical end points, and critical points on the $T-E_1$ phase diagram are detected.

14 pages, 15 figures

Cited by in corpus (3)

• 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${}_4$
• Electric field induced polarization rotation in squaric acid crystals revisited