Synthesis of platelet SrTiO3 by epitaxial growth on Sr3Ti2O7 core particles

A method for synthesis of platelet seeds by epitaxial growth of SrTiO₃ on Sr₃Ti₂O₇ core particles is reported. The aim of this study was to control the morphology, particle size, phase and chemical purity of SrTiO₃ seeds. Strontium titanate seeds will be used as templates in layered manufacturing to grow large lead magnesium niobate-lead titanate (PMN-PT) crystals within a polycrystalline matrix. Anisometric single crystal particles of Sr₃Ti₂O₇ were synthesized in molten KCl salt at 1200-1300°C. Plate-like morphology with a high aspect ratio of 7-10 was obtained. The XRD and SEM revealed a well-developed single crystal structure with rectangular faces. The plate-like Sr₃Ti₂O₇ particles were then reacted with TiO₂ in a second molten salt synthesis to prepare SrTiO₃. Platelet <001> SrTiO₃ particles with rectangular faces having an edge length of 10-40 μm and a thickness of 1-4 μm were obtained. The effects of processing steps on the morphology, particles size, and composition of the platelets are presented. The high aspect ratio SrTiO₃ platelets are suitable template candidates to achieve textured PMN-PT ceramics.