Piezoelectric properties of highly densified 0.01Pb (Mg1/2W1/2)O3-0.41Pb (Ni1/3Nb2/3)O3-0.35PbTiO3-0.23PbZrO3+0.1Â wt% Y2O3+1.5Â wt% ZnO thick films on alumina substrate

This paper reports on the formation of highly densified piezoelectric thick films of 0.01Pb(Mg1/2W1/2)O3-0.41Pb(Ni1/3Nb2/3)O3-0.35PbTiO3-0.23PbZrO3+0.1 wt% Y2O3+1.5 wt% ZnO (PMW-PNN-PT-PZ+YZ) on alumina substrate by the screen-printing method. To increase the packing density of powder in screen-printing paste, attrition milled nano-scale powder was mixed with ball milled micro-scale powder, while the particle size distribution was properly controlled. Furthermore, the cold isostatic pressing process was used to improve the green density of the piezoelectric thick films. As a result of these processes, the PMW-PNN-PT-PZ+YZ thick film, sintered at 890 °C for 2 h, showed enhanced piezoelectric properties such as Pr=42 μC/cm2, Ec=25 kV/cm, and d33=100 pC/N, in comparison with other reports. Such prominent piezoelectric properties of PMW-PNN-PT-PZ+YZ thick films using bi-modal particle distribution and the CIP process can be applied to functional thick films in MEMS applications such as micro actuators and sensors.