One-step mask patterning of micro lead zirconate titanate arrays by electrohydrodynamic atomization

Lead zirconate titanate (PZT) has been successfully fabricated via a unique one-step sintering processing route, which is simpler than the traditional precursor-calcinationmilling- pelleting-sintering route and is able to deliver an enhanced sintered density at a much reduced sintering temperature. The hydroxide precursor was prepared by coprecipitation from a mixed nitrate solution containing Pb2+, Zr4+, and Ti4+ ions, and it was then compacted into pellets without being calcined at a low temperature. The precursor pellets were dehydrated at 400, 500, and 600 °C for 4 h, respectively, followed by an isostatic pressing at 350 MPa, prior to being sintered at a high temperature. Dehydration temperature has a large impact on the sintering behavior of these hydroxide-derived PZT ceramics. The PZT dehydrated at 400 °C was seriously cracked when sintered at temperatures ranging from 950 to 1150 °C, due to the incomplete dehydration. A sintered density of 99.2% theoretical density was obtained at 1050 °C for 2 h for the powder pellet dehydrated at 500 °C for 4 h. It exhibits a dielectric constant of 1024 and a dielectric loss of 2.1% at a frequency of 1 kHz at room temperature. A calcination at a too-high temperature, e.g., 600 °C, results in a reduction in the sinterability of the precipitate-derived PZT ceramic.

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Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143961 ◽

1986 ◽

Vol 44 ◽

pp. 482-483

Author(s):

M.L.A. Dass ◽

T.A. Bielicki ◽

G. Thomas ◽

T. Yamamoto ◽

K. Okazaki

Keyword(s):

Lead Zirconate Titanate ◽

Direct Proof ◽

Lead Zirconate ◽

Subsolidus Phase ◽

Pzt Ceramics ◽

Subsolidus Phase Diagram ◽

Zirconate Titanate ◽

Two Phases ◽

Cbd Method ◽

Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

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