Lead zirconate titanate

About: Lead zirconate titanate is a research topic. Over the lifetime, 7141 publications have been published within this topic receiving 150878 citations.

Active micromixer for microfluidic systems using lead-zirconate-titanate (PZT)-generated ultrasonic vibration.

Abstract: A micromixer using direct ultrasonic vibration is first reported in this paper. The ultrasonic vibration was induced by a bulk lead-zirconate-titanate (PZT; 5 x 4 x 0.2 mm), which was excited by a 48 kHz square wave at 150 V (peak-to-peak). Liquids were mixed in a chamber (6 x 6 x 0.06 mm) with an oscillating diaphragm driven by the PZT. The oscillating diaphragm was in the size of 6 x 6 x 0.15 mm. Ethanol and water were used to test the mixing effectiveness. The laminar flows of ethanol (115 microL/min) and water (100 microL/min) were mixed effectively when the PZT was excited. The entire process was recorded using a video camera.

A novel micromachined pump based on thick-film piezoelectric actuation

Abstract: A new silicon-based micropump is described in this paper. The key element of the device is a thick-film/silicon micromachined hybrid actuator. The actuation principle relies on the flexure of a screen printed piezoelectric lead zirconate titanate (PZT) layer on a silicon membrane (8 mm × 4 mm × 70 μm). An investigation into the deposition technology of the bottom electrode for the piezoelectric material showed that a gold resinate or Pt evaporated electrode on a 500 nm thick SiO 2 covered silicon wafer achieved best results for the membrane actuator. Inlet and outlet valves are of the cantilever type and use deep boron diffusion together with KOH etching. Pump rates of up to 120 μl min −1 have been achieved. A maximum backpressure of 2 kPa was measured when using a 600 V pp sinusoidal drive voltage at 200 Hz across a 100 μm thick PZT layer. The pump was compared with a conventional surface mounted piezoelectric driven micropump. The conventional pump achieves a performance which was a factor of 3–6 more efficient, but does not allow mass production.

Effect of composition and temperature on electric fatigue of La-doped lead zirconate titanate ceramics

Abstract: Composition and temperature of ferroelectric La‐doped lead zirconate titanate ceramics influence its electric fatigue behavior, defined as the degradation of the electrical properties under the action of an ac field applied for a long time. Compositions of rhombohedral symmetry exhibit little or no fatigue compared with those of tetragonal and orthorhombic symmetry. At temperatures higher than the dielectric maximum, no fatigue effect was detected. Compositions close to phase boundaries (FE‐AFE, FE‐FE, or FE‐PE) display significant fatigue behavior. Electric fatigue arises from the pinning of domains by space charges or injected carriers or from microcracking. The former (which are charge related) is accompanied by smaller strains and is recoverable by thermal and electrical treatment, while the latter (arising from microcracking) arises from large incompatible stresses between grains and is a permanent damage. The understanding of the mechanism of electric fatigue gained in the present study provides gui...

Evaluation of intrinsic and extrinsic contributions to the piezoelectric properties of Pb(Zr1-xTx)O3 thin films as a function of composition

Abstract: The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the extrinsic contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated and measured piezoelectric coefficients as well as the dependence of piezoelectric and polarization behavior on the external field, i.e., hysteresis loop, are suggested to be primarily due to backswitching of 180° domains.