Application feasibility of Pb(Zr,Ti)O3 ceramics fabricated from sol-gel derived powders using titanium and zirconium alkoxides

It is believed that what may be termed the 'Nanoscaled Century' will lead to a new industrial revolution, particularly in terms of sol-gel methods of assembly for nanostructure devices. A propyl alcohol (I-Pro) based sol-gel chemical has been developed to replace 2-methoxyethanol (MOE), 1,1,1-tris(hydroxymethyl)ethane (THOME) for the fabrication of PbZr0.53Ti0.47O3 (PZT) piezoelectric ceramics. This chemical is prepared from sol-gel derived powders that are near to the morphotropic phase boundary (MPB). The pyrochlore phase was still apparent when calcining at 900 degreesC with a shorter calcining time, such as 30 min. However, it disappeared for longer calcining times, for example 3 h or more. From the results of the analysis, PZT ceramics calcinations at 900 degreesC for 4 h, and sintering at 1100 degreesC for 2 h could reach a pyrochlore-free crystal phase with relative density of approximately 7.9 g/cm(3)-close to 98% of the theoretical value. The P-E hysteresis loop, measured by the Sawyer-Tower circuit, revealed that the remanent polarization (P-r) and coercive field (E-c) were 8.54 muC/cm(2) and 15.6 kV/cm, respectively. The vibration modes of the PZT ceramics were between 150 and 1.5 MHz. Morevoer, under such processing conditions the PZT piezoceramics had uniform grain size distribution less than 1 mum and zero temperature coefficient of resonant frequency (TCF). In summary, the PZT ceramics derived from the sol-gel method were confirmed to possess excellent piezoelectric properties. Furthermore, the processing temperatures were scaled down by 100-200 degreesC, compared to conventional oxide reaction. Finally, from an energy-saving viewpoint, this experiment can potentially make a very positive contribution. (C) 2004 Elsevier Ltd. All rights reserved.