As layer thickness of multilayer ceramic capacitors decreases, nanoparticles of high dielectric materials, especially BaTiO 3, are needed. Tabular metal nanoparticles produce thin metal layers with low surface roughness via electrophoretic deposition. To achieve similar results in dielectric layers requires the synthesis and dispersion of tabular BaTiO 3 nanoparticles. In the current study, the synthesis of BaTiO 3 was investigated using a hydrothermal route. Transmission electron microscopy and atomic force microscpy analyses show that the synthesized particles are single crystal with a 〈111〉 zone axis and a median thickness of 5.8 nm and face diameter of 27.1 nm. Particle growth is likely controlled by the formation of {111} twins and the synthesis pH, which stabilizes the {111} face during growth. With limited growth in the 〈111〉 direction, the particles develop a platelike morphology. Physical property characterization shows the powder is of high purity with low hydrothermal defect concentrations and controlled stoichiometry.

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We report the successful synthesis of urea as a fuel for low-temperature microwave combustion-based synthesis of NiCr2O4 and La-doped NiCr2O4. Synthesis parameters include the kind of precursor, fuel, and container, as well as how external heat is provided to achieve the combustion reaction. Crystal structures, morphology, surface area, solar cells, Fourier-transform infrared spectrometry, and catalytic activity were used to characterize the products. No impurities phase formed in the as-synthesized NiCr2O4 sample, confirmed by XRD. Surface area was measured with a Brunauer–Emmet–Teller adsorption isotherm. Schottky and Frenkel formation energies have been investigated. This demonstrates the time needed for full decolorization of 4-Nitrophenol (yellow color) by NiCr2O4 and La-doped NiCr2O4. The La-doped NiCr2O4 (0.03%) showed the greatest catalytic activity compared to pristine and other La-doped NiCr2O4. The decolorization occurs in 10 min. The chemical hardness and surface area of the chromites appear to be important in determining catalytic performance. For multi oxide systems, the counter-doped ions in the A and B sites may alter the metal ion-oxide bond, promoting this partial oxidation process at the interface. The results suggest multiple research subjects focusing on such materials for the future.

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