Synthesis of Pure, Crystalline (Ba,Sr)TiO3 Nanosized Powders in Radio Frequency Induction Thermal Plasma

Abstract

Barium strontium titanate ((Ba,Sr)TiO3) nanosized powders were synthesized via spray pyrolysis of a liquid precursor mist in Ar–O2 radio frequency induction thermal plasma. To adjust the cation stoichiometry of the complex oxide, liquid precursors were prepared by mixing titanium butoxide (Ti(OBu)4) stabilized with diethanolamine and aqueous solutions of barium nitrate (Ba(NO3)2) and strontium nitrate (Sr(NO3)2) stabilized with citric acid. The molar ratios of titanium, barium, and strontium ions (Ba/(Ba+Sr) and (Ba+Sr)/Ti ratios) in the liquid precursor were varied. Pure, high‐crystalline (Ba,Sr)TiO3 (Ba/(Ba+Sr)=0.0–1.0) powders of ∼45 nm in size were synthesized in this one‐step process.

Influence of niobium doping on phase composition and defect-mediated photoluminescence properties of Eu3+-doped TiO2 nanopowders synthesized in Ar/O2 thermal plasma

“…In this case, the distortion of the TiO 2 lattice was alleviated, leading to the electric dipole transition becoming weak. On the other hand, the reduction in the number of defects gave rise to inefficient sensitization for the Eu 3+ activator by exciton recombination in less defect mediation through the energy transfer from the TiO 2 host lattice under indirect excitation [37].…”

“…As for the Eu 3+ -doped TiO 2 luminescent powders, it is energymediating defects that are dominantly related to the oxygen defects generated in the TiO 2 host lattice [37]. In this respect, regulation of the oxygen defects caused by the Eu 3+ doping by chemical composition adjustment in TiO 2 should affect the PL emission arising from the defect mediation.…”

“…The elemental compositions in these resultant powders have been proved to be almost equal to the prescribed amount in the precursor solutions. Recently, we have reported the synthesis of pure-phase nanocrystals in the full range of BaTiO 3 -SrTiO 3 solid solution by thermal plasma upon adjusting the cation stoichiometry in the liquid precursors and suppressing the formation of impurity phases [36].…”