Advanced dielectric properties of Li2O doped 0.2[Pb(Mg1/3Nb2/3 )]-0.8[PbTiO3-PbZrO3] ceramics

0.2Pb(Mg1/3Nb2/3)O-3-0.8Pb(Zr0.475Ti0.525)O-3 [PMNZT] ceramics doped with various contents of Li2O (0, 0.05, 0.1, 0.2, 0.3 wt.%) are fabricated by columbite precursor method. The lithium doping effect on the PMNZT ceramics is discussed in the relation to the piezoelectric properties and conduction behavior. The ferroelectricity is confirmed by polarization-electric field hysteresis loop. Remnant polarization P-r reached a maximum value of 27.16 mu C/cm(2) when a 0.1 wt% Li2O was doped. Coercive field E-c reached a maximum value of 8.27 kV/cm for 0.1 wt% Li2O and decreased again as Li2O ratio increased. The PMNZT + 0.1 wt.% Li2O ceramic attain the sufficient densification with large dielectric constant (epsilon(r) = 1448) and low dielectric loss (tan delta = 0.022) at room temperature. The maximum values of the longitudinal electromechanical coupling factor (k(33)) and piezoelectric coefficient (d(33)) of PMNZT + 0.1 wt.% Li2O ceramics are 78% and 565pC/N, respectively. The incorporation of Li+1 in the PMNZT ceramics has led to an appreciable reduction in conductivity throughout the temperature range of 30 similar to 400 degrees C. The activation energy of PMNZT + xLi(2)O ceramics calculated from the Arrhenius relation were (x = 0, 0.05, 0.1, 0.2, 0.3) were 1.05, 1.25, 1.27, 1.38 and 1.41 eV, respectively.