title: X-ray induced reduction of rare earth ion doped in Na2O-Al2O3-B2O3 glasses.
abstract: 5Na2O-10Al2O3-85B2O3 glasses doped with 0.05 mol% Sm2O3 or 0.05 mol% Eu2O3 turn to orange after irradiation by focussed femtosecond pulsed laser or x-ray irradiation. To know the mechanism of photo-induced coloring, the glasses were studied by Sm or Eu L(III) XANES before and after x-ray or UV irradiation. XANES in both edges showed that a part of trivalent ion converted to divalent ion upon the irradiation of x-ray. These facts reveal that photoreduction of rare earth ion is the mechanism of photo-induced coloring. However no photoreduction upon UV irradiation occurred in both glasses.
authors.affiliation: Osaka National Research Institute, AIST, Midorigaoka, Ikeda, Japan. shimizug@onri.go.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizugawa
authors.forename: N
authors.initials: N
authors.lastname: Umesaki
authors.forename: K
authors.initials: K
authors.lastname: Hanada
authors.forename: I
authors.initials: I
authors.lastname: Sakai
authors.forename: J
authors.initials: J
authors.lastname: Qiu