Structural, thermal and photoemission properties of erbium doped phosphate glass

Erbium doped Phosphate glasses with composition 70%V2O5.(30-x)%P2O5.x%Er2O3, where x = 0, 0.2, 0.4, 0.5, 0.7 and 0.9, were prepared by melt quenching technique. The structural properties of all prepared glasses are investigated by XRD, density, molar volume and FT-IR techniques. X-ray diffraction pattern confirms the amorphous nature of all samples, except for the heavy Er3+doped glasses which exhibit a partial crystallization. The density of the glasses is found to increase while the molar volume decreases with increasing Er2O3 content. Physical properties, such as OPD, field strength, average crosslink density, bond stretching force and the number of bonds per unit volume have been discussed. FT-IR analysis reveals a decrement in the intensity of the symmetric vibration modes of PO4 groups with an associated increment in the intensity of the asymmetric modes with introducing Er2O3. The characteristic temperatures and thermal stability of the glasses are investigated by using DTA measurement. In addition, the lattice thermal conductivity is found to increase from 0.325 to 0.54 W/m.oC with increasing the mol% Er2O3. Emission spectra of wavelengths 510, 545 and 585 nm are detected from all the Er doped samples when exposed to a light of wavelength 365 nm. The grown crystals are found to enhance the PL intensity due to the light scattering effect.