Hydrothermal synthesis of lead zirconate titanate (PZT or Pb(Zr0.52Ti0.48)O3) nano-particles using controlled ramping and cooling rates

• We fabricated PZT nanoparticles using hydrothermal process.
• The novelty is to control ramping and cooling rates for narrow size distribution.
• We use excess lead to significantly reduce amorphous phase and agglomeration.
• A continuous hydrothermal manufacturing process was developed to save time.

Lead zirconate titanate (PZT) nanoparticles with chemical composition Pb(Zr0.52Ti0.48)O3 hold many promising current and future applications, such as PZT ink for 3-D printing or seeds for PZT thick films. One common method is hydrothermal growth, in which temperature, duration, or mineralizer concentrations are optimized to produce PZT nanoparticles with controlled size and distribution. In this paper, we present a modified hydrothermal process to fabricate PZT nanoparticles. The novelty is to employ a high ramping rate (e.g., 20 °C/min) as well as a fast cooling rate (e.g., 5 °C/min). The former generates abrupt supersaturation to promote burst nucleation of PZT nanoparticles, and the latter provides a controlled termination of crystal growth. As a result, PZT nanoparticles with a size distribution ranging from 200 nm to 800 nm are obtained with good morphology and crystallinity. The chemical composition and crystal structure of the PZT nanoparticles are confirmed through use of energy dispersive X-Ray spectroscopy (EDS) and X-ray diffractometry (XRD). A cubic morphology is also confirmed via SEM images. The hydrothermal process is further modified with excess lead (from 20 wt.% to 80 wt.%) to significantly reduce amorphous phase and agglomeration of the PZT nanoparticles. Finally, an expedited hydrothermal manufacturing process was developed to substantially reduce the fabrication time.