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Photo‐Ionization of 3d‐Ions in Fluoride‐Phosphate Glasses
Author(s) -
Möncke Doris
Publication year - 2015
Publication title -
international journal of applied glass science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 34
eISSN - 2041-1294
pISSN - 2041-1286
DOI - 10.1111/ijag.12135
Subject(s) - materials science , ion , electron paramagnetic resonance , irradiation , fluoride , phosphate glass , analytical chemistry (journal) , valence (chemistry) , transmission electron microscopy , doping , laser , excimer laser , spectroscopy , ionization , inorganic chemistry , optoelectronics , optics , nuclear magnetic resonance , nanotechnology , chemistry , physics , chromatography , quantum mechanics , nuclear physics , organic chemistry
Interaction of radiation with glasses often modifies their properties (e.g., the refractive index). Most noticeable is a loss in transmission. Such phenomena can be exploited in photo‐sensitive materials, but have to be avoided in other applications. To improve the understanding of defect generation processes, a systematic comparison of defect formation in (fluoride‐)phosphate glasses doped with low concentrations of 3d ions was attempted. Samples doped with 10–5000 ppm of Ti, V, Cr, Mn, Fe, Co, or Ni were irradiated in the UV range by excimer lasers. Defects, which generally form in the levels of several ppm, were characterized by optical and by electron spin resonance spectroscopy. V 4+ was photo‐oxidized to the empty valence shell d 0 ion. Co 2+ , Mn 2+ , and Fe 2+ were all photo‐oxidized to the trivalent state while Ni 2+ was photo‐reduced. The fully oxidized Ti 4+ was also photo‐reduced. Cr 3+ showed photo‐disproportionation into Cr 2+ and Cr 6+ . Qualitative and quantitative changes in defect formation rates depend not only on the ion, but also on the radiation parameters, for example, the wavelength of the excimer lasers used (193, 248, 351 nm) or the initial transmission of the glass samples at the chosen laser wavelength. Defect recovery was followed up to 10 years after the irradiation experiments.