Glasses Tech

April 6, 2009

Thermally stimulated luminescence in X-ray irradiated oxide glasses doped with Ce(III)

Filed under: Glasses 1996 — admin @ 11:03 am

Eyeglasses

Thermally stimulated luminescence has been observed in X-ray irradiated alkali borate and sodium silicate glasses doped with Ce**3** plus . The emission wavelength is about 360 nm which corresponds to the 5d-4f transition of Ce**3** plus . For the alkali borate glasses doped with Ce**3** plus , oxygen hole center and electron trapped nearby alkali ion induced by X-ray irradiation contribute to the thermally simulated luminescence, while Sm**3** plus acts as an electron acceptor in the thermally stimulated luminescence of alkali borate glasses codoped with Ce**3** plus and Sm**3** plus . In both cases, Ce**3** plus is ionized by X-ray to form Ce**4** plus and an electron which is trapped by an impurity level (oxygen hole center or Sm**3** plus in glasses with or without Sm**3** plus , respectively). The thermal stimulation excites the electron (electron trapped nearby alkali ion or Sm**3** plus ), which transfers to the 5d level of Ce**3** plus . The electronic transition from the 5d to the 4f levels gives rise to the emission observed. The temperature which gives the maximum emission intensity in the glow curve tends to decrease as the concentration of Na//2O increases in the sodium borate glasses doped with Ce**3** plus and Sm**3** plus . In contrast, the temperature corresponding to the maximum emission intensity is independent of the glass composition for the sodium silicate glasses doped with Ce**3** plus and Sm**3** plus . These facts suggest that the compositional dependence of local basicity for Sm**3** plus ion site in sodium borate glasses is different than that in sodium silicate glasses. (Author abstract) 15 Refs.

Tanaka, K. Hirao, K. Tanaka, H. Soga, N.

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