Synthesis of holmium oxide (Ho₂O₃) nanocrystal by chemical bath deposition

Holmium oxide (Ho2O3) nanocrystals were prepared through an uncomplicated precipitation technique applying Chemical Bath Deposition. The effect by the reaction temperature (similar to 20 degrees C and similar to 90 degrees C samples) on the morphological, structural and some optical properties were investigated. Ho2O3 powder samples have been analyzed by applying SEM, FTIR, XRD and absorbance techniques. The crystalline morphology shows differences in grain boundaries as well as porosity and granular packaging. These crystalline materials have an acceptable stoichiometric balance. FTIR spectra show OH- and ions bands of different intensities, that are commonly incorporated in the surface and volume of these crystals. According to the XRD diffractograms, the crystalline cubic phase in both materials is identified. The grain size for each sample is located at range similar to 4.06-21.35 nm and similar to 21.15-35.35 nm respectively. The absorbance spectra investigated at UV-vis shows eleven absorption bands of different intensities located at similar to 278, similar to 287, similar to 333, similar to 345, similar to 360, similar to 415, similar to 448, similar to 472, similar to 485, similar to 535 and similar to 645 cm(-1) identified as Ho+3 electronic transitions occurring in the UV-Vis-region. The bandgap energies for each sample were Eg similar to 4.95 eV, and Eg similar to 4.85 eV respectively. The effect of the reaction temperature is manifested with the decrease in the grain size and carries with it the shifting of the E-g towards greater energy, which usually manifests itself in materials that have nanocrystals.