Dielectric and piezoelectric properties of Mg-Fco-doped PBSZT ceramics

A fluorine - oxygen substitution with yo at% F (yo = 2, 3 and 4) was perfor med in lead zirconate titanate ceramics with the nominal composition Pb-0.8 9(Ba, Sr)(0.11)(Zr0.52Ti0.48)O-3 (PBSZT). This starting material was also d oped with x at% Mg (x = 0.4, 0.75 and 1). The dielectric and piezoelectric properties of undoped, (yo at% Fl doped, (x at% Mg) doped and (x at% Mg and yo at% Fl co-doped PBSZT ceramics were compared. The study of three coeffi cients - Er, d(33) and Qm - revealed that F doping did not;induce significa nt changes in PBSZT characteristics whereas (Mg and Fl co-doping led to har der ceramics than MgO only doping. The influence of the different substitut ions on the temperature dependence of the dielectric constant and losses ha ve been investigated. A drastic increase of the Curie point was observed af ter (Mg and Fl co-doping associated with a diffuse ferroelectric/paraelectr ic phase transition. Experimental results indicated that neither Mg nor F h as a dominating effect on the characteristics of these co-doped PBSZT speci mens