*Gd2O3: A Luminescent Material DOI: http://dx.doi.org/10.5772/intechopen.92310*

*Rare Earth Elements and Their Minerals*

**86**

**4. Conclusions**

*Trapping parameters for optimized TL glow curve.*

*X, Y coordinates for CIE diagram for Gd2O3 phosphor.*

**Table 2.**

**Table 1.**

**Figure 11.**

*TL glow curve for 6 Cs<sup>−</sup><sup>1</sup>*

*TL glow curve for 6°Cs<sup>−</sup><sup>1</sup>*

*(Reproduced from [8]).*

The study confirms that the combustion synthesis method is suitable for large-scale production of the phosphor in minimum time. Structural characterization shows that the phosphors have monoclinic structure with particle size in the range of 8–12 nm. Phosphor synthesized by this method has homogenous particle

**Exposure Fuel μg E (eV) S (s<sup>−</sup><sup>1</sup>**

For 275 nm X 0.207 0.207

UV (254 nm) Urea 0.49 0.66 1.4 × 1010

 *heating rate and 10 min UV exposure with (A) urea fuel and (B) glycerin fuel.* 

 *heating rate and 1 kGy gamma exposure (C) urea fuel and (D) glycerin fuel* 

Gamma (1kGy) Urea 0.54 0.71 9.5 × 109

Glycerin 0.52 0.66 1.5 × 1010

Y 0.206 0.206

**Monoclinic Urea Glycerin**

Glycerin 0.50 0.72 9.7 × 109

**)**

size distribution. X-ray Photoelectron Spectroscopy (XPS) show the Gd (3d) level consists of a spin orbit split doublet, with the Gd (3d)5/2 peak is found at 1186.74 eV. Raman spectra was recorded with excitation of 633 nm wavelength, we found a broad and intense Raman peak at 340 cm<sup>−</sup><sup>1</sup> along with less intense peaks were observed at 375, 395, 424 and 451 cm<sup>−</sup><sup>1</sup> . The emission spectra have peaks in all UV and visible regions. So that, the phosphor may behave as white light emitting phosphor, which was further confirmed by its CIE coordinates. The CIE coordinates for combustion synthesized Gd2O3 phosphor have values *X* = 0.207 and *Y* = 0.206, and for the glycine synthesized Gd2O3 phosphor *X* = 0.209 and *Y* = 0.207. The values of CIE coordinates show that the Gd2O3 phosphor prepared by combustion synthesis emits blue color. The TL studies of both the phosphors were carried out under UV and gamma exposure. The activation energy for 0.66 eV and 0.71–0.72 eV for UV exposure and gamma exposure respectively. The value of shape factor μg for all the TL analysis was found in between 0.45 and 0.54, which shows that the phosphors follow the second-order kinetics.
