Views:2 Author:Site Editor Publish Time: 2017-12-17 Origin:Site
You Will Never Believe These Bizarre Truths Behind Piezoelectric Ceramics
Although PZT-based lead-containing piezoelectric ceramics dominate the piezoelectric field. However, PZT-based piezoelectric ceramics is a kind of material that is harmful to the human body and the environment. One of the toxic PbO in the process of processing and sintering easily volatile, harmful to the human body and the environment. Therefore, looking for a piezoelectric ceramic material that is comparable to PZT materials piezoelectric plate price without lead is an urgent need in the field of electronic materials. At present, the hot spots of research at home and abroad are mainly concentrated in two categories: bismuth-containing layered piezoelectric disc sensor datasheet and lead-free piezoelectric ceramics with perovskite structure. Bismuth layered (BLSF) piezoelectric ceramic is composed of two-dimensional perovskite and Bi2O2 layers is arranged alternately. It is special for layered structure that determines the following characteristics: low dielectric constant, high curie temperature, high electromechanical coupling coefficient, obvious anisotropy, high resistivity, low aging rate, large dielectric breakdown strength and low sintering temperature Wait. These characteristics of Pzt piezo ring resonance frequency determine the piezo ceramic that is particularly suitable for high temperature and high frequency applications, thus solving the PZT piezoelectric ceramic performance instability under high-power resonance defects. However, bismuth layered piezoceramic transducer ring effectspiezoelectric ceramics have their own drawbacks. First, the coercive field (Ec) is too high, which is not conducive to polarization. Second, the piezoelectric activity is low and the resistivity is low. In order to overcome these two shortcomings, the main use of high temperature piezo ceramic Pzt 8 polarization, as the coercive field decreases with increasing temperature with doping modification. In order to obtain high impedance, dope Nb5 + and V5 +. The results show that the densities of both BITN and BITV reach more than 95% of theoretical ones. The resistivity of BIT is 1010 ~ 1011cm, while that of BITN and BITV is about 1013 ~ 1014cm. In addition, Bi3TiTaO9 (BT T) is also doped, the result for Qm is up to 13,500. These properties determine the bismuth layer ceramic suitable for high temperature sensors, oscillators and filters.