摘要 : The polycrystalline samples of (Pb_(0.90)Ba_(0.10)) [(Zn_(1/3)Nb_(2/3))_(0.20)-(Zr_(0.51)Ti_(0.49))_(0.80)]O_3 [PBZN-PZT] compositions ceramics have been synthesized by substitution of barium in PZN-PZT by precipitation method and... 展开 The polycrystalline samples of (Pb_(0.90)Ba_(0.10)) [(Zn_(1/3)Nb_(2/3))_(0.20)-(Zr_(0.51)Ti_(0.49))_(0.80)]O_3 [PBZN-PZT] compositions ceramics have been synthesized by substitution of barium in PZN-PZT by precipitation method and finally by modified columbite method. X-ray diffraction (XRD) analysis of (Pb_(0.90)Ba_(0.10))(Zn)(1/3)Nb)(2/3))O_3 (PBZN) and PBZN-PZT shows a cubic and mixed phase of tetragonal and rhombohedral pure perovskite structure at room temperature. The dielectric dispersion of the solid solutions of PBZN-PZT has been studied as a function of temperature for the frequency range from 100 Hz to 1 MHz. The temperature (T) variation of the real components (ε') at different frequencies of the dielectric permittivity shows a broad maximum. The diffuse peaks in permittivity versus temperature confirm the relaxor behaviour of PBZN-PZT. The frequency dependence of maximum temperature (T_m) in these compounds with barium substitution is modeled using Vogel-Fulcher relation. 收起