Study On Electrical Properties And Defect Dipoles Of Manganese Doped Barium Zirconate Titanate Piezoelectric Ceramics

Piezoelectric ferroelectric materials are widely used in the development of science and technology,national defense and security,and people’s lives because of their unique function of mutual conversion of mechanical energy and electrical energy.Piezoelectric ceramics have attracted people’s attention because of their low cost and excellent performance.But currently,the piezoelectric ceramics in practical applications are mainly lead-containing piezoelectric ceramics with lead oxide as the main material,and its market share has reached more than 90%.As people’s awareness of environmental protection has gradually increased,the importance of lead-free piezoelectric ceramics is self-evident.People have begun to pay attention to improving the performance of the existing lead-free piezoelectric ceramics,in which the defect dipoles produced by acceptor doping It is more eye-catching because of the peculiar effect.The formation mechanism of the defect dipole and the mechanism of the internal bias field have been studied in depth,such as the principle of short-range order symmetry and the pinning effect proposed by Ren Xiaobing et al.However,the defect couple after polarization aging the dynamics of polarons under external field conditions has not been thoroughly studied.Research on the dynamics of defect dipoles mostly focuses on lead-containing systems.In the lead-free system,there are only three-phase and tetragonal-phase research content,lack of orthogonal phase research data,and the inherent physics of its movement during the aging process.The mechanism has not been studied in detail.Therefore,this article uses Mn-Ba(Zr_0.04Ti_0.96)O₃ piezoelectric ceramics to explore the effect of defect dipoles on various properties of ceramics,and investigates the degradation of defect dipoles through changes in external temperature and electric field frequency.The dynamics of the process.In this paper,starting from the preparation of ceramic materials,the solid-phase sintering method is used to prepare pure Ba(Zr_0.04Ti_0.96)O₃ ceramics in pure perovskite phase and Ba(Zr_0.04Ti_0.96)O₃ doped with 1 mol%Mn,and explore its The temperature conditions of the preparation are determined by XRD to be the orthogonal phase at room temperature,and the quality of the prepared samples is ensured by combining with SEM.After the preparation is completed,the dielectric properties,piezoelectric properties and ferroelectric properties of the pure BZT and Mn-BZT ceramic samples are tested respectively,and various performance parameters are extracted and analyzed.It is found that the performance of the ceramics under the pinning action of the defective dipole There are obvious changes,the dielectric constant and the piezoelectric constant are reduced,the saturation polarization and the residual polarization are reduced,but the loss is also reduced,and the mechanical quality factor is significantly improved.Moreover,since the oriented arrangement of the defect dipoles after polarization aging produces an internal bias field,it provides a means to study the dynamic characteristics of the defect dipoles during the aging process,and to study the effects of temperature and external electric field frequency on the internal bias field of Mn-BZT ceramics.Impact is also the focus of this article.The results of the study found that the increase in temperature makes the oxygen vacancies in the defective dipole obtain higher energy and is easier to migrate,resulting in a decrease in the internal bias field.At the same time,the decrease in the electric field frequency also provides more turning time for the defect dipole.This enables more defective dipoles to be flipped,and the internal bias field decreases accordingly.Finally,the relaxation function of the internal bias field is used to fit the relaxation time of the defect dipole at different temperatures,and the specific turning time at different temperatures is obtained.