Sol-gel derived europium doped CaMoO₄:Eu³⁺ with complex microstructural and optical properties

The crystalline compounds CaMoO4 doped with Eu³⁺ ions were prepared from nitrate-tartrate precursor gels at 650, 700, 750 and 800 °C temperatures. The obtained samples were characterized by thermal analysis (TG/DSC), Furier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and reflection measurements (UV-vis). TG/DSC analysis revealed the possible decomposition mechanism of synthesized Ca-Mo-O nitrate-tartrate gel. XRD data exhibited that even at 650 °C temperature the crystalline powelite (CaMoO ₄) structure has formed. To understand the crystal growth process of the CaMoO₄:xEu³⁺ compounds (x = 1, 2, 3, 4, 5 and 6 mol%), the influence of temperature on the surface morphology of the end products by SEM analysis was investigated. No evidence of organic residual in the final materials was found, confirmed by FT-IR analysis. UV-vis reflectance spectra revealed that by increasing of Eu ⁺ ions concentrations in the host material the reflection peaks of Eu₂O₃ also increased.