Effect of Electron Fluence on the Concentration of Color Centers in Hollow Particles of Aluminum Oxide.

The effect of a fluence of electrons with an energy of 30 keV in the range of (1–7) × 10¹⁶ cm^–2 on the concentration of color centers in micron-sized hollow particles of aluminum oxide is studied in comparison with bulk Al₂O₃ microparticles. The analysis is carried out in situ according to diffuse reflection spectra in the range from 250 to 2500 nm. The radiation resistance of the studied microspheres is estimated relative to Al₂O₃ microparticles from analysis of the difference spectra of diffuse reflection obtained by subtracting the spectra after irradiation from the spectra of nonirradiated samples. Changes in the difference spectra of diffuse reflection of aluminum-oxide microparticles and microspheres show that with an increase in the electron fluence, the induced absorption increases throughout the entire spectrum. It is established that the radiation resistance of aluminum-oxide microspheres to the action of electrons with an energy of 30 keV at a fluence of (1–7) × 10¹⁶ cm^–2 is greater than the radiation resistance of Al₂O₃ microparticles. An increase in the radiation resistance of hollow aluminum-oxide particles is due to a low concentration of radiation-induced defects in the anion sublattice. [ABSTRACT FROM AUTHOR]