Visible and mid-infrared spectral emissions and radiative rates calculations of Tm3+ doped BBLC glass.

Quaternary glasses with the composition 75Li2B2O7-(15-x)BaO-10CdO-xTm2O3 (BBLC) (0 ≤ x ≤ 2 mol %) have been prepared by melt-quenching method. The structure changes, the absorption coefficient of OH- and the maximum phonon energy of these glasses are studied by FT-IR spectra. Optical and emission properties of Tm3+ doped BBLC glasses have been investigated at room temperature. The optical band gap (Eopt), dispersion parameters and Urbach's energy (Eu) of the prepared samples have been estimated. Judd-Ofelt theory has been applied to obtain the radiative rates and optical intensity parameters. Oscillator strengths, radiative lifetimes, and branching ratio of different transitions have been calculated. Derived emission cross sections of the emission transitions in the visible range are determined. A strong emission is observed at 455 nm, this line is attributed to 1D2→3F4. Spectral line in the blue region has been observed at wavelength of 515 nm, as well. Two central wavelengths of 1.2 µm and 1.8 µm, which are located in the short- and mid- wave IR spectral regions, are analyzed. These emissions are attributed to the transitions 3H5→3H6 and 3F4→3H6, respectively.

Irradiation of silver and agar/silver nanoparticles with argon, oxygen glow discharge plasma, and mercury lamp.

The irradiation effect of argon, oxygen glow discharge plasma, and mercury lamp on silver and agar/silver nanoparticle samples is studied. The irradiation time dependence of the synthesized silver and agar/silver nanoparticle absorption spectra and their antibacterial effect are studied and compared. In the agar/silver nanoparticle sample, as the irradiation time of argon glow discharge plasma or mercury lamp increases, the peak intensity and the full width at half maximum, FWHM, of the surface plasmon resonance absorption band is increased, however a decrease of the peak intensity with oxygen glow plasma has been observed. In the silver nanoparticle sample, as the irradiation time of argon, oxygen glow discharge plasma or mercury lamp increases, the peak intensity of the surface plasmon resonance absorption band is increased, however, there is no significant change in the FWHM of the surface plasmon resonance absorption band. The SEM results for both samples showed nanoparticle formation with mean size about 50 nm and 40 nm respectively. Throughout the irradiation time with the argon, oxygen glow discharge plasma or mercury lamp, the antibacterial activity of several kinds of Gram-positive and Gram-negative bacteria has been examined.