The modification of contribution: electric conductivity, dielectric displacement and domain switching in ferroelectric hysteresis loops

The actual ferroelectric polarization can be misjudged due to the existence of the leakage current. How to distinguish the impact of each part is of great significance to evaluate the actual domain switching polarization and liner polarization. The current (I)–electric field (E) curves are suggested to distinguish the electric displacement contribution of electric conductivity D1, dielectric displacement D2 and domain switching polarization P. However, the previous model cannot accurately estimate the contribution of each part due to the inaccurate assumption. Thus, an alternative model had been constructed to demonstrate respective contributions of D1, D2 and P. Through the I–E curves, one baseline was made from the vertex (I > 0) at negative maximum electric field to another vertex (I > 0) at the positive and maximum electric field. The area above the baseline represents the domain switching P by high-order even power. The areas enclosed by I–E curve, baseline, and I = 0 line represent the contribution of electric conductivity. Besides, the parallelogram area represents the contribution of dielectric displacement D2. The accuracy of the present model had been verified by the simulation mean and fabrication in traditional BaTiO3 ferroelectric films. It shows that the contribution of electric conductivity D1 is two times than actual contribution by previous model, and dielectric displacement D2 is of great error than the actual one. And the present model is in more accordance with the actual contribution by constructing more accurate conductance form, and there is only small error in present model. It is revealed that the present model is more suitable to distinguish the contribution of each part than the previous one.