Generalization in context sensitive grammars
Radosław Zachariasz, Jan Ilczuk · Archives of Acoustics · 2007
In this work we report the synthesis of the Pb(Fe$_{0.5}$Nb$_{0.5}$)O$_{3}$ (PFN) powders and sintered ceramics. The ceramics were prepared from oxides: Fe$_2$O$_3$, Nb$_2$O$_5$ and PbO by two-stage columbite method by calcination. PFN powders were dried and formed in samples in shape of discs (10$\times$1) mm$^3$ and rectangular bars (26$\times$10$\times$1) mm$^3$. The samples were sintered by conventional ceramic sintering (CCS) method at temperature of 1323 K for 2 h in air. The density of the ceramic samples was determined to be $\rho = 8200$ kg/m$^3$. The obtained results of investigations of electric and mechanical properties such as: Young’s modulus $E$, electric permittivity $\varepsilon$ and tangent of dielectric loss of angle tan $\delta$ of the Pb(Fe$_{0.5}$Nb$_{0.5}$)O$_3$ ceramics obtained are presented.