EFFECTS OF SINTERING ATMOSPHERE ON DENSIFICATION BEHAVIOR AND PIEZOELECTRIC PROPERTIES OF PB(NI1/3NB2/3)O3-PBTIO3-PBZRO3 CERAMICS

Abstract

Densification of polycrystalline Pb(Ni1/3Nb2/3)O3-PbTiO3-PbZrO3 (PNN-PT-PZ) specimens was enhanced as the partial pressure of O2 in the sintering. atmosphere was increased. This observation was attributed to the increase in the internal pressure of a closed pore due to the thermal decomposition of PbO at a low partial pressure of O2. The relative dielectric permittivity (epsilon(r)), d33, k(p), and grain size of sintered specimens were also increased as the partial pressure of O2 in the sintering atmosphere was increased. The observed dependence of piezoelectric properties on the partial pressure of O2 was discussed in terms of the enhanced formation of the A-site vacancy (V(Pb)'') or the suppression of the B-site defect (V(O)) as the oxygen potential increased.