Impact of layer defects in ferroelectric thin films

TL;DR

This study uses a modified Ising model and Green's function technique to analyze how defect layers in ferroelectric thin films influence polarization, critical temperature, and excitation energy, aligning well with experimental observations.

Contribution

It introduces a theoretical approach to quantify the impact of various defect layers on ferroelectric thin film properties using a modified Ising model.

Findings

Defect layers can significantly alter polarization depending on exchange interactions.

The model predicts polarization variation with temperature, film thickness, and interaction strengths.

Results agree reasonably with experimental data on ferroelectric thin films.

Abstract

Based on a modified Ising model in a transverse field we demonstrate that defect layers in ferroelectric thin films, such as layers with impurities, vacancies or dislocations, are able to induce a strong increase or decrease of the polarization depending on the variation of the exchange interaction within the defect layers. A Green's function technique enables us to calculate the polarization, the excitation energy and the critical temperature of the material with structural defects. Numerically we find the polarization as function of temperature, film thickness and the interaction strengths between the layers. The theoretical results are in reasonable accordance to experimental datas of different ferroelectric thin films.