Effect of ball size and ball milling time on piezoelectric properties of 0.69PZT-0.31PZNN

0.69Pb(Zr_0.47Ti_0.53)O₃-0.31Pb[(Zn_0.4Ni_0.6)_1/3Nb_2/3]O₃ [0.69PZT-0.31PZNN] piezoelectric thick film was fabricated as a high energy density piezoelectric material by tape casting process. The effect of ball milling condition on properties of 0.69PZT-0.31PZNN thick film was investigated. As a result, the condition using 10 mm diameter zirconium balls for 48 hours is optimized ball milling condition. The highest d × g value of 13,819 × 10^-15 m²/N was obtained at this optimized ball milling condition and 1100°C sintering temperature. The highest d value of 251 pC/N was obtained and g value of 55.08 × 10^-3 Vm/N was obtained at the same condition. The cantilever beam structure piezoelectric energy harvesting (PEH) system was designed and manufactured by attaching fabricated 0.69PZT-0.31PZNN thick film to the SUS substrates with dimensions of 14 × 90 × 0.31 mm³. The frequency tendency of the open circuit voltage was analyzed. The rms open circuit voltage of the system had the highest peak of 5.1 V_rms at the resonance frequency of 37 Hz. The output voltage and output power of the system was measured at various load resistance. The maximum output power of 0.26 mW/cm³ was obtained at the matching load of 900 kΩ. The improved 0.69PZT-0.31PZNN thick film by optimizing ball milling condition can be a high energy density material for energy harvesting device.