The Cr3+ diffusion in chrysoberyl, bombarded with H+ ions and electrons, was

studied and compared with diffusion in non-irradiated samples. Chrysoberyl

crystals were irradiated with 6MeV H+ ions to fluences of 1 x 1016cm–2 for 25min

and with 10MeV electrons to fluencies of 2 x 1017/cm2 for 1h. Three different types

of samples, which were doped with Cr3+, were annealed in horizontal alumina tube

furnaces by 50K intervals at 1773 to 1923K for 200h. Scanning electron

microscope–energy dispersive X-ray spectrometry was used to measure the

diffusion. Arrhenius equations for the diffusion coefficient for Cr3+ at 1773 to

1923K were developed for electron-beam irradiated chrysoberyls:

D (m2/s) = 2.1 x 10−5exp[−482.3(kJ/mol)/RT],

proton beam irradiated chrysoberyls,

D (m2/s) = 2.3 x 10−3exp[−545.4(kJ/mol)/RT],

and natural non-irradiated chrysoberyls,

D (m2/s) = 2.2 x 10−3exp[−547.9(kJ/mol)/RT]

The results indicated that the chromium diffused deepest into the electron-beam

irradiated chrysoberyls.

Diffusion of Chromium in Chrysoberyl. Y.K.Ahn, J.G.Seo, J.W.Park: Journal of

Crystal Growth, 2009, 311[15], 3943-47