Green chemistry synthesis and structural and optical study of Dy₂(CO₃)₃ → Dy₂O₃ transition

This paper presents preliminary results of Dy₂(CO₃)₃ → Dy₂O₃ transition have been successfully obtained by Chemical Bath Deposition technical and subsequent thermal annealing temperature at ∼ 600°C. Two different temperatures of ∼ 20°C and ∼ 90°C ± 2°C are chosen to carry out the nanocrystalline growth. The crystalline phase is investigated by X-Ray Diffraction (XRD) and some optical properties;Transmittance, Reflectivity, Normalized Absorbance, real (n) and imaginary (k) parts refractive index. The crystalline phase of these inorganic nano materials for Dy₂(CO₃)₃ is orthorhombic phase, while for Dy₂O₃ it is cubic. Grain size average values located at ranged 2.8 − 3.4 nm for Dy₂(CO₃)₃ and ∼ 6.5 − 9.6 nm for Dy₂O₃. Vibrational modes are identified by Raman spectroscopy, modes at ∼ 150 − 1800 cm^-1 frequency range assigned to internal vibrations of CO2/3^- ion: v₁ symmetric stretching (∼ 1098 cm^-1) V₃-asymmetric −C −O stretching situated at ∼ 1063 cm^-1, were observed corresponding to orthorhombic crystalline phase. The F_g + A_g and A₁ ,_g modes, corresponding to cubic phase Dy₂O₃. Absorption measurement were assigned to the transitions from ground state (⁶H_15/2) to different excited states such as ⁴I_13/2 → ⁴F_7/2, ⁴I_15/2, ⁶F_3/2, ⁶F_5/2, ⁶F_7/2 → ⁶H_5/2, ⁶F_9/2 → ⁶H_7/2, ⁶F_11/2 → ⁶H_9/2 and ⁶H_11/2 of Dy³⁺ cation. Tauc's plot reveals band gap situated at range ∼ 4.66 − 5.17 eV forDy₂(CO₃)₃ and ∼ 4.26 − 4.80 eV for Dy₂O₃ respectively. (author)