Thermal behaviour of amorphous zircon prepared by ball milling

Results are presented on the recrystallisation behaviour of the mineral zircon (ZrSiO4) which has been amorphised by ball milling. X-ray diffraction and thermal analysis techniques were used to investigate the structural evolution after mechanical treatment. Phase transformations detected by the differential thermal analysis technique included transient formation of tetragonal or pseudo cubic ZrO2, followed by recrystallisation of zircon at reduced temperatures of around 1000 C. The behaviour of the milled samples was compared to literature data concerning amorphous zircon prepared by other techniques, including natural and ion beam radiation damage and sol-gel processing. The ball milled zircon was found to have similar thermal behaviour, but had a structural recovery temperature 180-600 C lower than that found for other amorphous samples. (orig.)