Numerical simulations of nonlinear and chaotic order parameter responses in bulk antiferroelectrics using ammonium dihydrogen phosphate parameter

Abstract

In this paper, the nonlinear and chaotic responses of bulk antiferroelectrics are elaborated phenomenologically and numerically. The first ordered phase of bulk antiferroelectrics is formulated by applying calculus of variations to Landau free energy density expansions of bulk antiferroelectrics. With applied time-dependent electric field, the antiferroelectrics dynamic responses are obtained by Landau–Khalatnikov equation of motion. The resulting dynamical equations are two nonlinearly-coupled second order differential equations corresponding to two inter-penetrating sub-lattices of antiferroelectrics, and these are solved numerically using forth-order Runge–Kutta methods and ammonium dihydrogen phosphate parameters in its first ordered phase. These calculated results are presented graphically for various frequencies and amplitudes in the applied electric fields.

Keywords

• antiferroelectrics
• ammonium dihydrogen phosphate
• chaos
• Landau free energy density
• nonlinear
• Poincare Sections