Fabrication and luminescence of Ce-doped GGAG transparent ceramics, effect of sintering parameters and additives

Ce-doped garnets find their use as scintillators as well as phosphors. Among synthetic garnets, gallium gadolinium aluminium garnet (GGAG) is a relatively new and interesting material, a mixed garnet that has displayed very good scintillation and luminescence properties. In the presented work Ce-doped GGAG ceramic samples were produced by reaction sintering from commercial oxide powders. The mixed powders were pressed into pellets and sintered. In order to achieve transparency of a ceramic material, it is crucial to eliminate porosity. Therefore, a number of process parameters and their influence on the microstructure and optical quality of the ceramics were studied: starting powders, sintering additives and sintering conditions. The sintering process consisted of two steps, viz. pressureless sintering in air followed by hot isostatic pressing. Luminescence properties of the sintered ceramics were studied by means of photo-luminescence and correlated to the fabrication process parameters.