Analysis of Er3+ diffusion within transparent YAG ceramics manufactured through various routes by SPS

Different bonding approaches were considered to develop layered composite ceramics of erbium doped yttrium aluminium garnet (Er:YAG/YAG) by Spark Plasma Sintering. More precisely three different strategies were envisaged, starting either from a stack of powders, pre-sintered or sintered ceramics. Highlighted by Electron Probe Micro Analysis (EPMA) analyses, these approaches led to different designs of interface i.e. doping profiles, linked to the different thermo-mechanical treatments applied, which have an influence on the grain boundary diffusion of erbium ions. The lengths of the diffusion were found to be of 12 μm, 63 μm and 140 μm respectively for fully dense, powder and pre-sintered assembly approaches.