Structures and Properties of Pb ( Zr 0.5 Ti 0.5 ) O 3 − Pb ( Zn 1/3 Nb 2/3 ) O 3 − Pb ( Ni 1/3 Nb 2/3 ) O 3 Ceramics for Energy Harvesting Devices

Piezoelectric ceramics with large energy density coefficient d 33 · g 33 value have been found suitable for piezoelectric energy harvesting applications. In this study, the phase structures and piezoelectric properties of x Pb ( Zr 0.5 Ti 0.5 )O 3 − y Pb ( Zn 1/3 Nb 2/3 )O 3 −(1− x − y ) Pb ( Ni 1/3 Nb 2/3 ) O 3 ( x PZT − y PZN −(1− x − y ) PNN ) ceramic were investigated with systematically varying PZN and PNN components. The ternary phase diagram of PZT − PZN − PNN system was illustrated and the composition region of morphotropic phase boundary (MPB) was determined. Piezoelectric and dielectric measurements verify that the materials in MPB region all present large d 33 and d 33 · g 33 values. In particular, very high d 33 · g 33 coefficients of 20162.2 × 10 −15  m 2 /N and 21026.3 × 10 −15  m 2 /N are observed from samples 0.75 PZT −0.15 PZN −0.1 PNN and 0.8 PZT −0.05 PZN −0.15 PNN with compositions located on the rhombohedral phase side near MPB because the dielectric coefficient ε 33 T /ε 0 decreases faster than the d 33 coefficient at this side.