Influence of Sm3+:Ag codoping on structural and spectroscopic properties of lead tellurite glass ceramics

Lead tellurite glass ceramics doped with Sm2O3 and codoped with fixed amounts of silver (Ag2O or Ag metallic nanoparticles, AgNPs) have been studied by X-ray diffraction (XRD), density measurements, Fourier transform infrared (FTIR), diffuse reflectance ultraviolet–visible (DR-UV–vis) and photoluminescence (PL) spectroscopies. The crystallite size and the quantitative ratio of the crystallographic phases in the samples were evaluated from the XRD data. FTIR spectroscopy data show that the glass ceramics network mainly consists of TeO3 and TeO4 structural units and the conversion between these units depends on the Sm2O3 content and the nature of the codopant (Ag2O or AgNPs) present in the samples. The DR-UV–vis spectra of studied samples were recorded in the 350–1000 nm spectral range at room temperature. The optical band gap (Egopt)for the studied glass ceramics were calculated from the DR-UV–vis spectra. The important peaks evidenced by PL spectroscopy measurements are due to the Pb2+ ions and Sm3+ ions present in the studied samples. The Sm3+:Ag codoping was found to produce quenching of the luminescence emission of Sm3+ ions in the studied samples.