Etude des proprietes dielectriques et piezoelectriques dans le systeme ternaire: Pb0.98Ca0.02(Zr0.52Ti0.48)0.98(Cr3.5,Ta5.5)0.02O3 effet du dopage.

Abstract

In this work, we studied the influence of P2O5 on the crystal structure, the microstructure and the dielectric and piezoelectric properties of a new ceramic material of the general formula: Pb0.98Ca0.02(Zr0.52Ti0.48)0.98(Cr3+ 0.5, Ta5+ 0.5)0.02O3 and of structure perovskite. The samples chosen for this study were prepared by a conventional oxide mixing technique. A thermal treatment was applied on these samples at different temperatures (1000, 1050, 1100, 1150 and 1180 °C). Various techniques of characterization were used for this study such as the X-ray diffraction, the scanning electron microscopy, the atomic force microscopy and electrical measurements. The results indicate that all the ceramics have a perovskite phase of tetragonal and rhombohedral symmetry. The sintering temperature of piezoelectric PZT-CTC can be reduced after the addition of phosphorus without compromising the dielectric properties. The density agglomerated of 94 \% of the theoretical density to been gotten for the addition of 4 wt. \% of P2O5 after the agglomeration to 1050 oC. Above or below 4 wt. \%, show a lower densification. Ceramics sintered at 1050 °C with 4 wt. \% P2O5 achieve excellent properties, which are as follows: kp = 0.73, $\rho$ = 0.09 � 10 (�. cm), $\epsilon$r = 18800, tan$\delta$ = 0.0094 and Tc = 390°C.