Fabrication and Parametric Analysis of Thermal Sensing Dielectric PZT Thick Film Nano Ceramic Device Developed by SOL GEL Technique

Abstract

Abstract
Extensive investigation carried out during earlier half of twentieth century, prominently established that the ionic radius of an atom gets reduced to significant levels with decrease in coordination number. The findings of Goldsmith and Pauling showed that ionic radii contracts by 4, 6 and 12% when coordination number is reduced from 12 to 8, 6 and 4 respectively. It is obvious that coordination number reduction takes place at the surface partly owing to surface tension phenomena. Recent past has seen extensive study in this field as it is realized that it plays a vital role in oxygen chemisorption, hence affecting various material properties when nano scaled particle size is considered. Pb[Zrx,Ti(1-x)]O3, popularly known as PZT has remained a point of attraction for the scientists and researchers in the field of synthetically developed engineering material since its discovery by Jaffe et al. Last few decades have seen various devices like miniature relays, smart structures, memories etc., all utilizing, to a major extent the well-known piezoelectric and pyroelectric properties found in PZT. After being reported about various parametric changes in piezoelectric coefficient, polarization and dielectric constant K by addition of some foreign ions lead to the further classification of PZTs as hard and soft PZTs. As reported by various authors, soft PZTs have highly enhanced piezoelectric properties which makes them highly suitable for fabrication of various electrical and electronic devices owing to high gain and better response, but on the other hand hard PZTs are reported to have highly decreased dielectric constants and piezoelectric coefficients leading their incapability to serve as an effective material for fabrication of actuators. However a considerable linearity in the variation of K is reported in these hard doped materials, which can indirectly be utilized for other low gain and low response systems. It is also been reported that when miniaturizing a device, the grain size plays an important role in governing various parameters like dielectric constant, Curie temperature, polarization etc. of the composite material. Due to the complexity and various independent constraints involved, the origin of grain size effect is yet to be understood well . In the presented work, the author investigates the nature of variation in Curie temperature, dielectric constant, and polarization of the composite material Pb[Zrx,Ti(1-x)]O3, for x=0.6, 0.7 and 0.8 and the effect of hard dopant Mg+2, with an objective to develop a composite solid solution of hard doped PZT which can be used as a temperature sensing element, when incorporated in a capacitive arrangement using simple electronic circuitry. Some interesting results are hereby obtained when the variation of polarization, dielectric constant and Curie temperature is studied in detail with the variation in grain size.
Keywords: PZT thermal sensors, XRD, hard doping, SOL-GEL fabrication technique

Cite this Article Kushal Roy. Fabrication and Parametric Analysis of Thermal Sensing Dielectric PZT Thick Film Nano Ceramic Device Developed by SOL GEL Technique. Research & Reviews: Journal of Physics. 2015; 4(1): 31–37p.