Effects of Zr/Ti ratio on the PbO-ZrO2-TiO2 system

Date

3-2006

Degree

Bachelor of Science in Applied Physics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Marvin U. Herrera

Abstract

The synthesis of lead zirconate titanate (PZT) was done via solid state reaction technique. The effect of varying the Zr/Ti ratio of the PZT on the physical properties is one of the objectives of this study. The samples were sintered at 1100°C for five hours. Four samples with various compositions were prepared. The samples were characterized using different characterization techniques such as Differential Thermal Analysis (DTA), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and porosity test. In the XRD data, it was observed that in a TiO2 rich composition, the products would be PZT or lead titanate (PbTiO3/PTO). The smallest amount of Zr02 (in this case 0.1) yielded more PZT formation. In decreasing the amount of Ti02, PTO and PZT were formed. PbZrO3 (PZO) could not be formed because most of the Zr02 are used in the formation of PZT. The presence of PTO increases at 0.3 and 0.5. This was correlated to the relative stabilities of PTO and PZO, which results to the decomposition of PZO during the reaction. Through the DTA, the melting points of the samples were determined. A trend was observed in the melting point and it resembles a typical binary phase mixture of eutectic composition. The sample with 0.2 Zr/Ti ratio has the lowest melting point which was identified as the eutectic point. The result of the SEM images supported the prediction in the binary phase. A "stripy" microstructure known as lamellar microstructure, which are alternate layers of alpha and beta in a eutectic composition, was observed at 0.2 Zr/Ti ratio. This was also supported by the XRD result, wherein two incompatible phases were found to be present at 02 composition which agrees to the characteristic of eutectic point. It was also found that this composition has the highest porosity value (because of the presence of two phases) and lowest bulk density.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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