First Principles’ Investigation of Electronic Properties of Hf, Ag, Cd, Zn, Ce, Nd, Sm-Modified Lead Zirconate Titanate

Abstract

First principles investigations, including density functional theory (DFT) have been applied to calculate the electronic properties of A-site modified lead zirconate titanate (PZT). The theoretical explanation for the origin of fatigue in ferroelectric perovskite oxides was implemented to study the fatigue behavior. The explanation indicates that, the fatigue is related to the weakness of π bond between Ti 3d and O 2p states, caused by the occupancy of the Ti 3d state by electrons which released from oxygen vacancies. If a certain energy state of the additive element founded to be overlapped with the Ti 3d state at conduction band minima, then it will sharing the electrons released by oxygen vacancies with the Ti 3d state. Therefore, when the Ti 3d state become less occupied with electrons the π bond between the Ti 3d and O 2p states become more maintained and the composition is less susceptible to fatigue.