Simultaneous aluminium-26 and oxygen-18 transport in an alumosilicate glass

Abstract Simultaneous 26 Al and 18 O tracer diffusion experiments were performed in an alumosilicate glass (60 mol% SiO 2 , 10 mol% CaO, 10 mol% Na 2 O, and 20 mol% Al 2 O 3 ). For the determination of the Al diffusion a novel technique was used, insofar as the isotope 26 Al (half-life 7.4 × 10 5 years) was not used as a radioactive but as a quasi-stable tracer. Combined with a SIMS measurement the tracer concentration profiles could be obtained. At 800 °C D Al = 2.7 × 10 -21 m 2 /s and D O = 3.4 × 10 − 19 m 2 /s resulted. This observed difference in mobility is presumably related to the dissimilar roles the constituents Al and O play in the glass structure.