Khanitha Wanchai. Effect of Sm3+, Pr3+ and Eu3+ doping on the piezoelectricity of lead zirconate titanate ceramics . Master's Degree(Applied Analytical and Inorganic Chemistry). Mahidol University. : Mahidol University, 2003.
Effect of Sm3+, Pr3+ and Eu3+ doping on the piezoelectricity of lead zirconate titanate ceramics
Abstract:
The purpose of this work is to study the effect of doping Sm3+, Pr3+ or Eu3+ up to 2 mol % into lead zirconate titanate ceramics (PZT, 52/48) which were prepared by conventional mixed oxide method. The mixed powders were calcined and sintered at 800 C for 2 h and 1200 C for 1 h, respectively. The crystal structure and some physical properties such as particle size distribution, microstructure, density of the products were investigated, as well as their electrical and piezoelectric properties of all the PZT ceramics (εr , kp, Qm, d33 , P-E hysteresis) and Curie temperature. The results showed that the average particle sizes of the calcined products were in the range 1.47 2.36 μm and tend to decrease with increasing dopant content. The morphologies of all sintered products showed homogeneous, dense grain and low porosity. The average grain sizes were in the range 1.06 4.93 μm, and also decreased with increasing dopant content. Analysis of composition in the ceramics via SEM/EDX revealed that the Zr/Ti ratio was close to the expected value (52/48) but a small amount of dopant could not be detected, due to the sensitivity of the technique. The density of ceramics was higher than 95 % of the theoretical density in most cases. The sintered products exhibited a tetragonal phase and the tetragonality tended to decrease as the amount of dopant was increased. The εr , kp and d33 values of the doped PZT were higher than PZT undoped. On the other hand, the Qm of the doped PZT was smaller than PZT undoped. Furthermore, Qm and d33 tended to decrease with increasing dopant. The Pr, Ps and Ec values of doped PZT were higher than undoped PZT. The PZT doped
with 0.05 mol % Pr3+ showed highest Tc (336.6 C).