Yttrium aluminum garnet as a scavenger for Ca and Si

Doped yttrium aluminum garnet, Y3Al5O12 (YAG), has drawn considerable attention for solid-state industrial, medical and scientific laser applications. The crystal optical activity is closely related to the type and amount of doping element. Studies on highly yttrium doped, creep resistant alumina ceramics with Ca and Si contamination have indicated that YAG precipitates in the ceramic had a propensity to allow simultaneous incorporation of Ca and Si impurities on the order of 1 % in their structure. Co-solubility potential for Ca and Si in YAG crystals was investigated through systematic doping and co-doping YAG polycrystals with Ca2+ and/or Si4+. It was shown via X-ray diffraction and electron probe microanalysis techniques, that the ceramic can accommodate more than order of magnitude larger amounts of Ca2+ and Si4+ when incorporated in equal amounts simultaneously than when the dopants are introduced alone. The co-solubility limit for Ca and Si was determined to be between 3 and 4 % of the cation amount in pure YAG. Enhanced co-solubility was discussed in terms of size and charge compensations in the lattice. Co-doping with a suitable element is introduced as a possible way to increase the solubility of useful cations in this ceramic that is the host material for lasers