Application testing of Sr doping effect of PZT ceramics on the piezoelectric transformer gain and efficiency proposed for MEMS actuators driving

摘要

Effect of Sr content in lead zirconate titanate PZT ceramic system on performance of piezoelectric transformer application were studied. Our experiments provide consistent evaluation of doping strontium amount on piezoelctric coefficients values and final voltage gain and efficiency of piezoelectric transformer. Extreme values of these parameters are preferred for MEMS device effective driving. Modification of ferroelectric materials with isovalent ions, however with the bigger radii than the original atoms, significantly affects their properties. Particularly the electromechanical coefficients of (Pb_(1-x)Sr_x)(Zr_(0,70)Ti_(0,30))O_3, for mole %'s as x=0.05, 0.10 and 0.15 ceramics exhibit marked increase, if the PSZT material stoichiometry is near the ferroelectric/relaxor phase boundary. To determine the piezoelectric coefficients, the resonance-antiresonance method was implemented. The results indicated that addition of Sr~(2+) ions in the amount of 5 mol% in the ceramic structure maximally increased the values of piezoelectric parameter to d_(31)=8.2 pC/N and mechanical quality factor Q_m=2902. Finally we demonstrated that in spite of the high piezoelectric coefficients for certain material only the practical examination must be applied in order to draw decisive application conclusions due to the complexity of the double energy conversion in such a specific device as the piezoelectric transformer.