Combined-Method Synthesis of CaTiO3 and SrTiO3 Perovskites with n-Hexane: Impact on Structure and Microstructure

Abstract

This study reports the synthesis of CaTiO₃ and SrTiO₃ with a perovskite structure by a combined route involving preliminary wet mixing of CaCO₃/SrCO₃ carbonates and TiO₂ in n-hexane, followed by a solid – state reaction during high-temperature calcination. The phase composition and crystal structure of the obtained materials were examined by X-ray diffraction with Rietveld refinement, while the microstructure and elemental distribution were studied using SEM\EDX, and local structure and surface groups were probed by ATR– FTIR spectroscopy. It is shown that the presence of the organic solvent and the applied thermal treatment lead to the formation of single-phase CaTiO₃ and SrTiO₃ with orthorhombic and cubic modifications, respectively, and with crystallographic parameters with reference PDF cards. The average crystallite size calculated using the Sherrer equation confirmed the nanocrystalline nature of the powders, whereas SEM/EDX analysis reveals a highly porous microstructure and a homogeneous elemental distribution without noticeable metallic impurities. It is established that A-site cation substitution Ca²⁺/Sr²⁺ in combination with n-hexane wet mixing induces systematic changes in lattice symmetry, IR band positions and agglomerate morphology, enabling targeted tuning of the texture and potential functional properties of perovskite titanates. The proposed combined approach is a technologically simple and scalable method for producing nanostructured oxide perovskites that are promising as supports and active phases in catalytic systems for combustion processes, plasma-chemical oxidation and functional ceramics.