The effect of alkali niobate addition on the phase stability and dielectric properties of Pb(Zn1∕3Nb2∕3)O3 based ceramic

Abstract

Enhanced dielectric, ferroelectric, and electrostrictive properties of Pb(Mg1/3Nb2/3)0. While Pb͑Zn 1/3 Nb 2/3 ͒O 3 -PbTiO 3 ͑PZN-PT͒ single crystals have shown superior ferroelectric properties, less scientific and technical interests have been placed on PZN-PT polycrystalline ceramics due to their poor thermodynamic stability and the difficult processing conditions. Here, we stabilized the PZN-PT based ceramics by adding alkali niobates such as NaNbO 3 ͑NN͒ and KNbO 3 ͑KN͒ and investigated their structure and dielectric properties. Two stabilization mechanisms are suggested in alkali niobate added PZN-PT ceramics, increased tolerance factor and enhanced electronegativity difference. KN stabilized the perovskite structure of PZN-PT based ceramics more effectively than NN. Both PZN-PT-KN and PZN-PT-NN ceramics showed the typical behavior of relaxor ferroelectrics. The temperature of maximum dielectric constant of PZN-PT-NN was slightly higher than that of the PZN-PT-KN, which was explained by the difference in ionic size and B-site ordering.

Composition Design Rule for High Piezoelectric Voltage Coefficient in (K0.5Na0.5)NbO3Based Pb-Free Ceramics

“…Hence, the difference among them was investigated at the view point of their tolerance factor and electronegativity. The tolerance factor (t) and electronegativity difference (ÁX) were calculated as [26][27][28][29]…”

Structural change in polar nanoregion in alkali niobate added Pb(Zn1/3Nb2/3)0.95Ti0.05O3 single crystal and its effect on ferroelectric properties

“…where each of R A , R B , and R O is the ionic radius of A-site cation, B-site cation, and oxygen ion in ABO 3 perovskite structure, respectively. 15,16 However, low thermodynamic stability of PZNT with small tolerance factor and difficulty in growing single crystals has prevented further study on the unique features of PZNT based solid solutions. The effect of alkali niobate doping on the structure of PNRs, the long range ferroelectric domain, and the E-field induced phase transition is not well understood yet.…”