A study on the stability of a PZT precursor solution based on the time evolution of mean particles size and pH

The stability of lead titanate zirconate (PZT) precursor solutions is analyzed by taking into account the time evolution of their particles size distributions and pH. Solutions were synthesized by a hybrid sol–gel route carefully chosen in order to attain the maximum coordination number for all of the (Zr/Ti)4+ cations involved in the chemical reaction. Dynamic light scattering (DLS) and pH measurements were carried out for samples up to 4 months old and some noticeable features were detected in all cases: i.e. mean particles size (〈d〉) was well below 10 nm, particles size distribution functions tend to become unimodal only after a few days from synthesis and, after some time, the pH evolution seems not to influence the values of mean particles size. DLS results were also used to formulate a fairly accurate physical description of our systems on the basis of the classical Smoluchowski theory for colloidal dispersions in the approximation of van Dongen–Ernst.