Synthesis of needle-like BaTiO3 particles from the thermal decomposition of a citrate precursor under sample controlled reaction temperature conditions

Abstract

Needle-like BaTiO₃ particles with controlled microstructure have been prepared from the thermal decomposition of a metal-organic precursor under sample controlled reaction temperature (SCRT) conditions. In a first step, a mixed barium and titanium citrate precursor consisting of a single phase compound with controlled morphology and stoichiometry have been prepared. The precursor has been converted isomorphologically into BaTiO₃ by thermal treatment under SCRT conditions. The so-obtained needle-like particles are constituted of self-assembled nanoparticles. The size of the assembled subunits has been tailored by controlling the reaction rate and the partial pressure of the gases generated during the thermal decomposition of the barium titanium citrate. This microstructural control accomplished by the SCRT method can not be achieved by conventional thermal decomposition of the citrate precursor. Finally, the set of samples obtained with different microstructures has been investigated in terms of stabilization of the cubic phase at room temperature.