Relaxor ferroelectric properties of PZT-PZN-PMnN Ceramics

Abstract

xPb(Zr_0.47Ti_0.53)O₃-(0.925-x)Pb(Zn_1/3Nb_2/3)O₃-0.075Pb(Mn_1/3Nb_2/3)O₃+0.7%wt Li₂CO₃ (PZT-PZN-PMnN) ceramics with x=0.65-0.9 have been prepared by two-stage calcination method. The effect of the PZT content on the relaxor behavior and ferroelectric properties of ceramics has been investigated. The degree of diffuseness (<img src='/image/spc_char/gamma2.gif' border=0>) from 1.72 to 1.85 indicates that all of compositions show a diffused phase transition with the strong frequency dispersion, which is characteristic of relaxor ferroelectric materials. The sharpness of the permittivity peak shows that the compositions are gradually approached normal ferroelectric behavior when the mol fraction of PZT increases. At x = 0.80, dielectric and ferroelectric properties of ceramics are optimal with the mass density (<img src='http://www.niscair.res.in/jinfo/rho.gif' border=0>) of 7.81 g/cm3, the dielectric constant (εr) of 1230, the dielectric loss (tan<img src='/image/spc_char/delta1.gif' border=0>) of 0.005 and the remanent polarization (Pr) of 27 <span style="font-family:Symbol;mso-ascii-font-family:" times="" new="" roman";="" mso-hansi-font-family:"times="" roman";mso-char-type:symbol;mso-symbol-font-family:="" symbol"="" lang="EN-GB">mC/cm2.

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