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

Abstract

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 applying 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 nanomaterials 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  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 Fg+ Ag and A1g modes, corresponding to cubic phase Dy2O3. Multiple absorption bands with different relative intensities are observed at UV-Vis-NIR region, assigned to 4fs→4fs intra-electronic transitions and band gap energy. Absorption measurement were assigned to the transitions from ground state (6H15/2) to different excited states such as 4I13/2→4F7/2, 4I15/2, 6F3/2, 6F5/2, 6F7/2→6H5/2, 6F9/2→6H7/2, 6F11/2→6H9/2 and 6H11/2 of Dy3+ cation. Tauc’s plot reveals band gap situated at range ~4.66-5.17 eV for Dy2(CO3)3 and ~4.26-4.80 eV for Dy2O3 respectively.