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The up-conversion emission of Nd 3+ , Sm 3+ and Er 3+ has been studied in a new halogenoantimonite glass with the chemical composition 80 Sb 2 O 3 -10 ZnBr 2 -10 KCl. Doping concentration was 0.2 mol% of lanthanide (Ln) ions. Rare earths were introduced as fluorides LnF 3 that were further converted into oxides. Main physical properties of base glass were measured, including density, thermal expansion, characteristic temperatures, refractive index and optical transmission. The amount of residual hydroxyls was calculated from the OH absorption band around 3000 nm. The recorded up-conversion emission lines are λ em = 536 nm for Nd 3+ pumped at 805 nm; λ em = 563 nm, 600 nm, 631 nm and 645 nm for Sm 3+ pumped at 945 nm; λ em = 531 nm for Er 3+ pumped at 798 nm. Co-doped glass (0.1 Yb 3+ + 0.1 Er 3+ ) pumped at 980 nm has three emission lines at 524 nm, 545 nm and 650 nm. Corresponding transitions have been identified and the mechanisms ruling the up-conversion process is discussed. They include excited state absorption (ESA), energy transfer (ET) cooperative energy transfer (CET), emission assisted by phonon (EAP), multiphonon relaxation (MR) and cross-relaxation (CR).

International audienceThe unconventional Heavy Metal Oxide Glasses (HMOG) are characterized by a low phonon energy, large infrared range transmission, high refractive index and nonlinear optical properties. Ternary glasses have been synthesized and studied in the Sb2O3– MoO3-ZnCl2 system. Further, the glass formation compositional limits are reported and some glass samples with the formula: (90-x)Sb2O3 -xMoO3–10 ZnCl2 (10 ≤ x ≤ 50, mole%) were elaborated. Thermal properties have been measured and indicating that the glass transition temperature decreases with increasing proportions of molybdenum oxide. The evolution of density, microhardness and elastic modulus has been studied as functions of parameter x and Raman spectra measurements have been shown the partial conversion of MoO6 octahedral units into MoO4 tetrahedral

Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics.Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains.The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO. The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials)and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.