Influence of carbon contamination on transparency of reactive SPSed Nd3+:YAG ceramics

Influence of carbon contamination from the paper and dies on structural-phase state and transparency were studied for SiO2-doped Nd3+:Y3Al5O12 ceramics obtained via reactive spark plasma sintering (SPS). It is shown that the transparency of post-annealed ceramics is sensitive to the SPS temperature. Since the swelling effect is related to the amount of the carbon phases as well as their composition and depth of location, the degradation becomes remarkable with the temperature increasing above critical for SiO2-doped Nd3+:Y3Al5O12 system. Ceramics fabricated at 1500°C contains SiC and SiOC-based impurity phases, which are relatively stable for post-annealing. Removal of generated defects is possible for ceramics fabricated at relatively low temperatures (~1350°C).