Effect of Y―doping on the Ferroelectric Properties of BSPTHigh―temperature Piezoelectric Ceramics

(1― x)Bi(Sc1― yY y)O3― xPbTiO3(BSYPT― x/y) ceramics were prepared by theconventional mixed oxide method, and their crystal structure, microstructure, andferroelectric properties were investigated. XRD analyses show that the crystalstructure of BSYPT― x/y ceramicschanges from rhombohedral to tetragonal symmetry with increasing of PbTiO3amount. The introduction of BiYO3 into BiScO3―PbTiO3solid solution would cause a shift of morphotropic phase boundary (MPB) of BSYPT― x/y system from x=0.62, y=0.05 to x=0.56, y=0.20. The BYSPT― x÷y ceramics with x=0.58 and y=0.15 showthe pinched hysteresis loops, which can be attributed to the pinned domainwalls of the dipolar defects following the substitution of Sc3+ and Ti4+ions for Y3+ ions in B site of BYSPT system.