Double doping effect on the structural and dielectric properties of PZT ceramics

• Published in: Journal of physics. D, Applied physics Vol. 37; no. 22; pp. 3174 - 3179
• Main Authors: Goel, Puja, Yadav, K L, James, A R
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.11.2004; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Niobates, titanates, tantalates, pzt ceramics, etc; Physics; Differential scanning calorimetry; Scanning electron microscopy; Frequency dependence; Inorganic compounds; Curie point; Dielectric properties; Transition element compounds; Polycrystals; Titanates; XRD; PZT; Relaxor; Ferroelectric materials; Sintering; Dielectric losses; Zirconates; Chemical composition; Microstructure; Permittivity; Activation energy
• DOI: 10.1088/0022-3727/37/22/019
• ISSN: 0022-3727

Polycrystalline samples of the modified Pb(Zr1-x Tix)O3 (PZT) composition, with representative formula Pb0.92(LazBi1-z)0.08(Zr0.65Ti0.35)0.98O3 (PLBZT), a family of relaxor ferroelectrics, were prepared via the chemical route with z = 0.,0.6 and 0.9. Crystalline phases of powders calcined at different temperatures and the microstructure of the sintered pellets were investigated by x-ray diffraction (XRD) analysis and scanning electron microscopy, respectively. XRD confirms the result obtained by differential scanning calorimetry. The XRD profile shows that the samples having z = 0.9 and 0.6 do not exhibit a pyrochlore phase, whereas the samples with z = 0.3, have 3% of the pyrochlore phase. Microstructural analysis suggests that the shape of grains and intergranular residual pores are modified upon La doping. The dielectric constant and dielectric losses were measured as a function of frequency at room temperature for different frequencies starting from 0.1 kHz to 1 MHz. The dielectric constant was found to be strongly influenced by frequency whereas the Curie temperature remained almost the same. Finally, we conclude that the dielectric constant, loss and activation energy of PLBZT strongly suggest that these compounds are suitable for the preparation of high value capacitors and may be good candidates for device applications.