Combinatorial hydrothermal synthesis and characterisation of perovskites

In the present work we have applied combinatorial methodology to the hydrothermal synthesis and characterisation of perovskites. In a first series with 48 samples in the (Pb,Ba,Sr)ZrO3 compositional field, synthesis conditions were optimised by variation of pH. In a second series of 96 samples the (Pb,Ba)(Zr,Ti)O3 compositional field was investigated, with the aim to control crystallinity and particle size. Using powder X-ray diffraction (XRD), it was established that most compositions crystallised readily within 3–23 h at 200 °C in 2.0–3.3 M KOH. Using scanning electron microscopy (SEM), particle size was determined to be from 3 to 8 μm for the pure zirconates to 0.2–1 μm for the pure titanates. Microprobe wavelength dispersive spectroscopy (WDS) was used for chemical analysis. It was found that particle size was determined primarily by bulk chemistry whereas a polyacrylamide additive and pH had little effect. It has been shown that combinatorial hydrothermal synthesis and characterisation techniques are fully applicable to the synthesis and basic characterisation of perovskites.