Hydrothermal synthesis, dielectric properties of barium titanate, cobalt doped barium titanate, and their graphene nanoplatelet composites

Abstract

In this work, pure barium titanate (BT) and cobalt doped barium titanate (CBT) were synthesized by using barium chloride, tetrabutyl titanate, cobalt chloride, and titanium chloride as precursors via a two-step hydrothermal process. These precursor mixtures were further blended with a dispersion of surfactant + graphene nanoplatelets (GNP) judiciously during the second step of hydrothermal process to obtain their respective BT-GNP and CBT-GNP nanocomposites. The morphological and crystal structures of BT, CBT, BT-GNP, and CBT-GNP samples were analyzed by the powder XRD, and FESEM revealed that the formations of 10-to 30-nm-sized cubic phase BT, CBT nanoparticles with least amount of agglomerations, and more spherically shaped particles in the CBT, whereas their nanocomposite morphologies and compositional elemental mapping showed random distributions of BT and CBT particles over the GNP. The FT-IR analysis indicated the presence of strong chemical interactions between the nanoparticles and GNP sheets in both the BT-GNP and CBT-GNP nanocomposites. Furthermore, the dielectric measurements carried out on the BT, CBT, BT-GNP, and CBT-GNP samples showed tremendous influences of metal doping and GNP on the BT which can support to tune its dielectric properties for several storage applications. K E Y W O R D S barium titanate, cobalt doping, nanocomposite, dielectric property, graphene nanoplatelets 1 | INTROUDCTION Barium titanate (BT) is a widely studied electroceramic material for various device applications such as capacitors, memory storage devices, thermistors, piezoelectric transducers, and sensors due to its excellent dielectric, piezoelectric, and ferroelectric properties. 1-6 In recent years, improving the dielectric, ferroelectric, and ferromagnetic properties of BT ceramics by doping with metals and oxide additives has attracted a great deal of research interests for their use in increasing the performance of several electronic devices. 4,5 Usually, the BT powders are synthesized by a number of leading routes, for instance, sol-gel, 7 coprecipitation, 8 hydrothermal, 9,10 Pechini, and electrochemical methods. 11 The metal doping in BT ceramics is achieved via the methods such

Enhancement of Photocatalytic Activity and Microstructural Growth of Cobalt-Substituted Ba1−xCoxTiO3 {x = 0, …, 1} Heterostructure

“…This difference induces a lattice strain, according to Mahmoud et al [90], and significantly causes the shrinkage of the optical bandgap, as manifested by absorption red shifting in the UV spectra. 5) [91]. Therefore, the obtained results are in good agreement with those of the X-ray diffraction analysis.…”

Sintering‐driven effects on the band gap of (Pb,La)(Ti,Ni)O3 photovoltaic ceramics

“…34 When compared to PbTiO 3 , the data from the absorbance curves of (Pb 0.8 La 0.2 )(Ti 0.9 Ni 0.1 )O 3 revealed that, independently of the sintering temperature, the substitution of Ti 4+ by Ni 2+ decreased the band gap, as theoretically predicted for Pb(Ti,Ni)O 3-δ 6,8 and observed in some works. 1,2,[35][36][37] Although our composition is nominally charged neutral, our data show that the replacement of Ti 4+ by Ni 2+ is the main contribution to narrow the band gap, in comparison to the parent PbTiO 3 .…”

Facile preparation and dielectric properties of BaTiO3 with different particle sizes and morphologies

“…2,3 Barium titanate nanoparticles are widely used to make small, high-capacity microcapacitors and temperature-compensating components; 4,5 as well as nonlinear components, dielectric ampliers, memory components for electronic computers, ceramic sensitive components, microwave ceramics, and piezoelectric ceramics. 6,7 In recent years, with the continuous development of the electronics industry, the demand for BaTiO 3 -based ceramics has been increasing; and higher requirements for BaTiO 3 purity, particle size, crystal shape, and dispersion have been proposed. 1,8 There is broad utility in preparing high-purity, ultrane BaTiO 3 powder.…”