Structural, Physical and Optical Properties Of Rare Earth Oxides Doped Calcium Phosphate Glasses with and Without Silver Nanoparticles

Abstract

This thesis describes the synthesis, optimization and systematic characterization of rare earth (La, Ce, Er, and Eu) doped Calcium phosphate glasses as well as these glasses' incorporation with silver nanoparticles. The high-purity raw ingredients were weighed and mixed according to the molar composition. A series of glass samples in the composition of 50P2O5-(50-x) CaO-xREI (0.0 ≤ x≤ 5.0 mol% and rare earth ions (REI) = La, Ce, and Er), 50P2O5-(50-x) CaO-xEr2O3-4Ag2O-SnO (0.0 ≤ x ≤ 5 mol% ) and 50P 2O5-49CaO- 1REI- 4Ag2O-SnO (REI=Eu3+ and Er3+) were synthesized using melt-quenching technique and subsequent heat treatment applications. The Taguchi approach of DOE with orthogonal array was used to optimize the process parameters of glass preparation utilizing the melt quenching technique. The impact of rare earth ion addition and co-doping of Silver nanoparticles on the structural, physical, and optical characteristics of calcium phosphate glass were analysed using different techniques. The samples were thoroughly characterized using X-ray diffraction, Density measurements, Transmission electron microscopy (TEM) and SAED, Fourier transform infrared, ultraviolet-visible (UV-Vis) absorption, photoluminescence (PL), FESEM, and EDAX. XRD confirmed the samples' amorphous nature. Utilizing TEM image micrographs and ImageJ software, the average size of AgNPs was estimated to be about 12nm. Its images manifested the nucleation of homogeneously distributed spherical silver (Ag) nanoparticles in the glass matrix. Using Fourier transform infrared (FTIR) spectroscopy, the vibrational mode of these glasses was examined. FTIR spectra revealed the bonding vibrations for P-O bonds, P-O-P linkages, and PO2 units. The primary metaphosphate glass structure had not been affected by the production or development of silver nanoparticles, according to Fourier-infrared (FTIR) spectroscopy. The absorption spectrum of rare earth oxides doped P2O5-CaO glasses with and without incorporating Ag nanoparticles was analysed for band gap and Urbach energy. The optical properties of glasses containing rare- earth ions and noble-metal nanoparticles were examined to determine whether there were any ways to increase the luminescence efficiency of rare-earth ions.