Synthesis and characterization of barium titanate-based solid solution nanocubes

Ba(Zrx,Ti1−x)O3 nanocubes (BZTx NCs) were synthesized by hydrothermal reaction with titanium and zirconium aqueous compounds and surfactants. The nanocubes were assembled on the substrates by dropping-drying method. The microstructures of the nanocube were evaluated by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The ordered assemblies of the NCs were yielded on the substrate when Zr contents were below 0.2. BZT0.2 NCs had narrow size distribution about 20 nm observed by FE-SEM and TEM. On the other hand, BZT0.5 and BaZrO3 NCs were attached each other and they formed large cube above 100 nm. Perovskite phase was confirmed in all BZTx NCs by X-ray diffraction. Lattice constant of BZTx NCs increased linearly with increasing Zr contents. The composition of BZT0.2 NCs were calculated by X-ray photoelectron spectroscopy. These results suggest that the ratio of Ba:Zr:Ti is nearly equal to the nominal ratio. Crystallographic phase of BaTiO3 and BZT0.2 NCs was characterized by Raman spectroscopy under various measurement temperatures.