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Tailoring the shape, size, crystal structure and preferential growth orientation of perovskite plate-like particles prepared under hydrothermal and molten salt synthesis conditions
Pēdējās izmaiņas veiktas:
21.03.2017

Marjeta Maček-Kržmanc, Alja Čontala and Danilo Suvorov (Advanced Materials Department, Jožef Stefan Institute)

The current tendency for the miniaturization of electronic components, together with the development of nanotechnology, has increased the interest in preparing and investigating ABO3-type perovskite nanoparticles with defined anisotropic shape. The self-assembling of nanocrystals with a controlled shape, size and crystal orientation enables the fabrication of well-oriented two- (2D) or three-(3D) dimensional nanostructures with enhanced functional properties, which are expected to make breakthroughs in the fields of memory storage, piezoelectric sensors, ferroelectricphotovoltaic devices, photocatalysis and energy harvesting.

Due to the high symmetry of the crystal structure, ABO3-type perovskite crystals do not show a tendency to grow in anisotropic, defined shapes such as plates or needles. The growth of such perovskite crystals could be realized only by using anisotropically shaped templates. In this research, we investigated the formation of perovskite Ba1-xSrxTiO3 (0≥x≤1) micro-plates and nano-blocks by the topochemical transformation of a layered perovskite Bi4Ti3O12 precursor template. The mechanism of the topochemical transformation from Bi4Ti3O12 in to Ba1-xSrxTiO3 were studied under hydrothermal and molten salt synthesis conditions.

The influence of the Bi4Ti3O12 template dimensions and the conversion conditions on the size, crystal structure and preferential orientation of the formed perovskite microplates and nano-blocks were examined in great details. The main focus was on of preparing highly tetragonal (002)-oriented Ba1-xSrxTiO3 plates. Their piezoelectric, ferroelectric characteristics and domain structure were studied by means of electronmicroscopy, differential scanning calorimetry (DSC) and piezo-force microscopy (PFM).

The application potential of highly oriented micro-plates and nano-blocks based on Ba1-xSrxTiO3 and BaTiO3/SrTiO3 composites will be represented.