Simultaneous aluminium-26 and oxygen-18 transport in an alumosilicate glass
Simultaneous 26Al and 18O tracer diffusion experiments were performed in an alumosilicate glass (60mol% SiO2, 10mol% CaO, 10mol% Na2O, and 20mol% Al2O3). For the determination of the Al diffusion a novel technique was used, insofar as the isotope 26Al (half-life 7.4×105years) 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 DAl=2.7×10-21m2/s and DO=3.4×10−19m2/s resulted. This observed difference in mobility is presumably related to the dissimilar roles the constituents Al and O play in the glass structure.