Evaluation of Structural and Optical Properties of Nanocrystalline Cubic Y₂O₃ Phase Materials via Combustion Method Using Different Fuels

Abstract

We have carried out combustion synthesis of nanocrystalline Y2O3 materials using hexamine, polyethylene glycol(200) (PEG(200)), and ethylene glycol (EG) as fuels. In addition, the impact of mechanical stirring of commercial Y2O3 powder with various dilutions of PEG(200) with distilled water as a solvent was also examined. The as-prepared combustion product of the hexamine is significantly different from other fuels (PEG(200) and EG). The annealed combustion products crystallize in the pure cubic Y2O3 phase. The combustion product of PEG(200) reveals a maximum weight loss of ~46% at 800°C in the TG curve. The UV-Vis-NIR features of different samples show quite interesting results. The Eg values obtained from the Tauc plots are found in the range of 5.48 to 5.71 eV for the different samples. The observed strong FTIR band at 560 ~ 415 cm−1is owing to the vibrational Y-O bond in the present series samples. The Raman spectra show the highest intensity peak at wavenumber 374 cm−1is owing to the Fg vibrational mode of the Y2O3phase. Agglomerated nature of nanoparticles is seen in the Y2O3 phase samples obtained from EG and hexamine as fuels.

Detailed Studies on the Synthesis Methods and Characterizations of Nanocrystalline Cr2O3 Phase Materials for NIR Pigmentation Applications

“…The UV-Vis-NIR spectral features of different Cr 2 O 3 samples were measured in both absorbance and reflectance modes in the instrument JASCO spectrophotometer using the light source of D2/WI. [37][38][39] The FT-IR spectral features of the samples were scanned in the FT-IR spectrometer (Nicolet iS50/Thermo Fisher Scientific) in transmittance ATR mode. 38,39 The Raman spectra were scanned in the range 80 to 1000 cm −1 using He-Ne as a laser source (632.8 nm) in the Horiba Jobin-Yvon LabRam HR800 spectrometer.…”

“…[37][38][39] The FT-IR spectral features of the samples were scanned in the FT-IR spectrometer (Nicolet iS50/Thermo Fisher Scientific) in transmittance ATR mode. 38,39 The Raman spectra were scanned in the range 80 to 1000 cm −1 using He-Ne as a laser source (632.8 nm) in the Horiba Jobin-Yvon LabRam HR800 spectrometer. [37][38][39] The micro-images (FESEM) and elemental analysis (EDX) of the Cr 2 O 3 phase nanomaterials were taken from the Inspect F FESEM equipment.…”

“…38,39 The Raman spectra were scanned in the range 80 to 1000 cm −1 using He-Ne as a laser source (632.8 nm) in the Horiba Jobin-Yvon LabRam HR800 spectrometer. [37][38][39] The micro-images (FESEM) and elemental analysis (EDX) of the Cr 2 O 3 phase nanomaterials were taken from the Inspect F FESEM equipment. [37][38][39] Results and Discussion XRD.-Figure 5 represents the XRD patterns of precursor salt, Cr(NO 3 ) 3 .9H 2 O and the thermally treated precursor to see the phase formation of Cr 2 O 3 and its purity at different temperatures, 200 °C-900 °C.…”

“…[37][38][39] The micro-images (FESEM) and elemental analysis (EDX) of the Cr 2 O 3 phase nanomaterials were taken from the Inspect F FESEM equipment. [37][38][39] Results and Discussion XRD.-Figure 5 represents the XRD patterns of precursor salt, Cr(NO 3 ) 3 .9H 2 O and the thermally treated precursor to see the phase formation of Cr 2 O 3 and its purity at different temperatures, 200 °C-900 °C. While screening the XRD patterns illustrated in Figs.…”

“…The Cr 2 O 3 materials obtained above 350 °C indicate the rhombohedral structure with space group, R-3c h (167) and the indexing of the peaks are done for the same crystal system by analyzing the XRD data using Jana program. [37][38][39][40] XRD patterns of wet chemical (precipitation and hydrothermal) synthesized as-prepared and annealed samples along with ballmilled commercial Cr 2 O 3 powder are depicted in Fig. 6.…”