Effect of La2O3 Additions on Microstructure, Morphology and Pressure Sensing Behaviour of PZT Based Ceramics Sintered in Al2O3 Environment

Abstract

Effect of La2O3 addition on microstructure, morphology and pressure sensing behaviour of (Pb1-x, Lax)(Zr0.52, Ti0.48)O3 based ceramics was studied in three different compositions of La2O3, namely x = 0.10, 0.12 and 0.15. The samples were prepared through a conventional solid-state reaction method using high purity metal oxides powders. In order to control the PbO losses due to high sintering temperature, a novel approach was explored whereby the samples were sintered in Al2O3 environment. Structural investigation using XRD revealed that all samples exhibited a tetragonal crystal structure. However the c/a ratios exhibited a decreasing trend as the La2O3 content increased, indicating that (Pb1-x, Lax)(Zr0.52, Ti0.48)O3 crystals gradually evolved towards pseudocubic structure. SEM micrographs showed that in all samples the grains have uniform pebble stone morphology. The average grain size reduced from ~ 4.5 µm to ~ 3.0 µm with the increment of La¬2O3 content. The performance of pressure sensing behaviour which was investigated using custom-made pressure chamber showed that sample with composition of x = 0.10 exhibited the best piezoelectric properties with high pressure sensitivity, good stability and repeatability.