Search results for "Fluorine doping"
showing 3 items of 3 documents
Slow magnetic fluctuations and superconductivity in fluorine-doped NdFeAsO
2015
Among the widely studied superconducting iron-pnictide compounds belonging to the Ln1111 family (with Ln a lanthanide), a systematic investigation of the crossover region between the superconducting and the antiferromagnetic phase for the Ln = Nd case has been missing. We fill this gap by focusing on the intermediate doping regime of NdFeAsO(1-x)F(x) by means of dc-magnetometry and muon-spin spectroscopy measurements. The long-range order we detect at low fluorine doping is replaced by short-range magnetic interactions at x = 0.08, where also superconductivity appears. In this case, longitudinal-field muon-spin spectroscopy experiments show clear evidence of slow magnetic fluctuations that …
-ray-induced intrinsic defect processes in fluorine-doped synthetic SiO2 glasses of different fluorine concentrations
2009
Fluorine-doped synthetic SiO2 glass is suitable for investigating intrinsic defect processes in SiO2 glass because of the high radiation hardness and the low concentrations of defect precursors such as the strained Si O Si bonds and impurity-related network modifiers including SiOH, SiH, and SiCl groups. When the concentrations of the defect precursors are minimized by moderate fluorine doping into SiO2 glass, formation of oxygen vacancy–interstitial pairs (Frenkel pairs) is the primarily Co60γ-ray-induced defect process. However, heavy fluorine doping tends to degrade the radiation hardness and enhance the formation of the silicon and oxygen dangling bonds, suggesting the presence of anoth…
Irradiation induced defects in fluorine doped silica
2008
International audience; The role of fluorine doping in the response to UV pulsed laser and c radiation of silica preforms and fibers was studied using electron spin resonance (ESR) spectroscopy. Exposure to radiation mainly generates E0 centers, with the same effectiveness in fibers and in preforms. The E'concentration in F-doped silica fibers is found to increase with UV energy fluence till a saturation value, consistently with a precursor conversion process. These results show the fluorine role in reducing the strained Si–O bonds thus improving the radiation hardness of silica, also after drawing process.