A Novel, Controlled, and High-Yield Solvothermal Drying Route to Nanosized Barium Titanate Powders

Abstract

In this report, we describe a novel solvothermal procedure for the synthesis of nanosized particles of barium titanate (BaTiO 3 ). We have been able to synthesize large amounts of nearly uniform sized BaTiO 3 nanocrystals in the size range of 5-37 nm. The advantages of our technique over other previously reported hydrothermal/ solvothermal approaches are the high yield and the simple but precise control of the size of the particles, which is very conveniently achieved by changing the water content of the reaction mixture in a measured way. The particles are systematically characterized by powder X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED), high-resolution TEM (HRTEM), disc centrifugation, thermogravimetric and differential thermal analyses (TGA-DTA), infrared spectroscopy (IR), and inductively coupled plasma-optical emission spectrometer (ICP-OES). The as-synthesized BaTiO 3 nanopowders contain BaCO 3 byproduct as well as internal OHgroups and residual solvent species that can be removed by acid washing following heating. However, it is shown that this procedure results in the substantial change of the chemical composition and strong degradation of real microstructure of nanosized BaTiO 3 particles.

Microwave-hydrothermal synthesis of barium strontium titanate nanoparticles

“…5 supports the nanometric nature of barium strontium titanate particles obtained at 130 • C by the hydrothermalmicrowave method which present diameters between 40 and 80 nm. These values are inside the range of distribution sizes corresponding to tetragonal nanoparticles, according to Kolenko et al [39]. They observed that samples with particle size smaller than 17 nm present only cubic structure, whereas samples with particles grown larger than this value have only tetragonal structure.…”

Interplay between Size, Composition, and Phase Transition of Nanocrystalline Cr3+-Doped BaTiO3 as a Path to Multiferroism in Perovskite-Type Oxides

“…Although the measured d spacings would indicate mostly tetragonal phase for NCs prepared in water and mostly cubic phase for those prepared in ethanol and benzyl alcohol, given the uncertainly in these measurements it is difficult to assign the d spacings unambiguously to either of these two phases. Similarly, Kolen'ko et al 35 performed selected-area electron diffraction (SAED) measurements to identify the structure of BaTiO 3 nanoparticles, but the weakly resolved rings did not allow for conclusive identification. Therefore, further characterization is needed for the crystal structure determination.…”

Barium titanate core – gold shell nanoparticles for hyperthermia treatments

“…However, in the optimized conditions, H 2 O 2 removes the adsorbed carbonate from the surface of the nanoparticle in a manner comparable to what occurs in a weak aqueous acetic acid solution. 66 As a consequence, when the particles were placed in H 2 O 2 immediately after treatment with acid (nitric acid in our case), skipping the washing step or failing to properly wash the particles to reach neutral pH, the resulting mixture appeared yellowish with large clod-like aggregations of particles that were not easily broken. On the basis of these observations, the combination of acid and H 2 O 2 causes an excessive loss of barium ions that leads to the degradation of the particle surface and its structure.…”