Dielectric properties of barium zirconate titanate nanocube 3D-ordered assemblies

Single-crystalline barium zirconate titanate nanocubes (BZ(x)T NCs; x is Zr contents) with various composition of Zr/Ti ratio were synthesized by hydrothermal method using water-soluble titanium and zirconium complex and surfactants. The highly-ordered assemblies of the BZT NCs were directly fabricated on the substrate by dipcoating method with low withdrawal rate. High dielectric constant above 4200 and relative low loss tangent below 1% with extremely small frequency dependence were achieved in the case of BZ(0.2)T NC assembly. The temperature dependence of capacitance of BZ(0.1)T NC assembly was quite small from -60 to 150 degrees C. A specific peak in the Raman spectra of BZ(0.2)T NC assembly was slightly shifted to lower wavenumbers from 294 to 288 cm(-1) after heat-treatment which meant the change of local bonding condition was induced by local strains at the interfaces. Zr-substitution and local strain synergistically affected to the dielectric properties of BZT NC assemblies. (C) 2018 The Ceramic Society of Japan. All rights reserved.