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The luminescence of sapphire subjected to the irradiation of energetic hydrogen and helium ions

1996; Institute of Physics; Volume: 29; Issue: 8 Linguagem: Inglês

10.1088/0022-3727/29/8/002

1361-6463

C. Jardin, B. Canut, S.M.M. Ramos,

Radiation Detection and Scintillator Technologies

The luminescence of during and irradiation was measured in the 190 - 820 nm wavelength range. The luminescence evolution with the ion fluence exhibits two behaviours : (i) at low fluence, the amount of centres increases; (ii) at high fluences, these defects are completely (F centres) or partially ( centres) annihilated. This phenomenon results from two concomittant mechanisms : a conversion between F and defects and a destruction of both luminescent species resulting from the radiation-induced damage. By using a simple model we have determined the cross sections associated with creation and annihilation of the centres. The irradiated samples were also investigated by cathodoluminescence and Auger electron spectroscopy. A higher concentration of structural defects and centres is evidenced at the sample area previously irradiated by ions, leading to an unsteady regime of the surface potential under electron excitation.