Published online by Cambridge University Press: 02 July 2020
Trace impurities and dopants in sintered ceramics, often at levels below 100 parts per million, can significantly affect the performance of the materials. In alumina (A12O3), it is believed that calcium and silicon, which are the main background impurities, cause abnormal grain growth. The addition of magnesium to alumina produces several beneficial results, including enhanced densification and improved corrosion resistance of the ceramic. For example, LUCALUX®, which is a dense, transparent ceramic, is made by adding a small amount of MgO (<0.25%) to the alumina. Primarily because they are difficult to detect and image, it has not been easy to determine experimentally the mechanisms by which trace constituents influence the sintering of ceramics. Imaging secondary ion mass spectrometry (SIMS) is a valuable analytical technique for the submicrometer characterization of ceramics. Relevant to this study, magnesium and isotopes of silicon, which have largely eluded detection by traditional techniques, can be measured with SIMS.