Anisotropic dielectric properties of two-dimensional matrix in pseudo-spin ferroelectric system

• Monte Carlo simulations were carried out for the 2D pseudo-spin Ising model in order to study the anisotropic dielectric properties of 2D lattice sizes under transverse and longitudinal electric fields.
• While the longitudinal dielectric constants at different temperatures have similar values and are less invariant with lattice size around Tc, the transverse dielectric constants exhibit a sharp peak indicating the increase of Slater defects with lattice size in the x–y plane.
• The transverse dielectric constants are responsible for the Slater H2PO4 groups.

The anisotropic dielectric properties of a two-dimensional (2D) ferroelectric system were studied using the statistical calculation of the pseudo-spin Ising Hamiltonian model. It is necessary to delay the time for measurements of the observable and the independence of the new spin configuration under Monte Carlo sampling, in which the thermal equilibrium state depends on the temperature and size of the system. The autocorrelation time constants of the normalized relaxation function were determined by taking temperature and 2D lattice size into account. We discuss the dielectric constants of a two-dimensional ferroelectric system by using the Metropolis method in view of the Slater–Takagi defect energies.

Schematic proton configurations for Takagi defects (H3PO4-HPO4) and Slater defects with different internal energy levels in the ferroelectric system.Figure optionsDownload high-quality image (204 K)Download as PowerPoint slide