The Influence of Titanium Substitution on Phase Transition Energy and Crystalline Composition in the Complex La2−xTixMo2O9+x/2 System

The aqueous sol–gel preparation technique was successfully employed for synthesizing a homogeneous La–Ti–Mo–O tartrate gel precursor, and thermal treatment at 1000 °C promoted the formation of nanocrystalline complex La2−xTixMo2O9+x/2 ceramic. X-ray diffraction analysis revealed a consistent influence of increasing the degree of titanium substitution on the formation of the La2Mo2O3 and La2MoO6 impurity phases within the crystalline mixture. Meanwhile, the stability of the high-temperature cubic β-La2Mo2O9 phase in the La2−xTixMo2O9+x/2 system at room temperature highlighted the distinct influence of titanium content from structural and thermodynamic perspectives. However, the Raman spectroscopy analysis showed no distinct variations in the spectra of La2−xTixMo2O9+x/2 samples, suggesting a substantial effect of titanium on the phase transition behavior between the low-temperature monoclinic α-La2Mo2O9 and the high-temperature cubic β-La2Mo2O9 phases.