نوع مقاله : مقاله پژوهشی
1 دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف
2 دانشکده مهندسی و علم و مواد، دانشگاه صنعتی شریف
عنوان مقاله [English]
In this research, the effects of Lanthanum and Niobium oxides on the microstructure and electrical properties of a solid solution
of lead Titanate Zirconate Piezoelectric Ceramics were studied in the morphotropic regions, with a composition of Pb1.1(Zr 0.53Ti0.47)O3. Samples were prepared via a conventional ceramic procedure and the Lanthanum oxide content was in the range of 0-3 \%. The results showed that, in the sample with mole 2\% Lanthanum oxide, the densification and sintering were improved at 12000C. Although both cations are in the Lantanate group and, usually, therefore, must act as donor type additives, the difference in the atomic radii caused different behavior. It would seem that La is more compatible with the structure and has more solubility. With more La, the second phase was observed, which created some tension. This cannot be compensated for by the tetragonality of the system. Besides which, Lanthanum oxide reduces the grain size distribution of the system. Regarding the effects of Nd, these effects were started at lower amounts, but, its effect on the density was not significant. The electrical measurements indicated improvements up to mole 2\% of the additives and a reduction thereafter.