Effects of Sintering Atmosphere on Densification Behavior and Piezoelectric Properties of Pb(Ni 1/3 Nb 2/3 )O 3 –PbZrO 3 Ceramics

Densification of polycrystalline Pb(Ni 1/3 Nb 2/3 )O 3 –PbTiO 3 –PbZrO 3 (PNN–PT–PZ) specimens was enhanced as the partial pressure of O 2 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 O 2 . The relative dielectric permittivity (ε r ), d 33 , k p , and grain size of sintered specimens were also increased as the partial pressure of O 2 in the sintering atmosphere was increased. The observed dependence of piezoelectric properties on the partial pressure of O 2 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.