Influence of strontium doping on the ferroelectric and piezoelectric properties of lead zinc niobate-lead zirconate titanate ceramics

The crystal structure, ferroelectric and piezoelectric properties of pyrochlore-free lead zinc niobate-lead zirconate titanate ceramics were investigated systematically as a function of Sr doping as well as thermal treatment. The results showed that the remanent polarization (Pr) has decreased significantly with increase in strontium content. After annealing, the value of squareness of hysteresis loop (Rsq) increased from 1.48 to 1.74 for the annealed sample. Furthermore the annealed samples exhibited larger Pr and lower coercive fields (Ec) compared with as-sintered samples. The results indicated that the ferroelectric and piezoelectric properties in Sr-modified PZT-PZN were further improved by thermal annealing.