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A method for synthesizing YSAG:Yb optical ceramics has been developed. Additionally, the phase composition and unit cell parameters for YSAG, YbSAG, and their solid solutions have been determined. The limits of scandium solubility in the dodecahedral and octahedral sites of garnet crystal lattice have been estimated after annealing at 1600°C. The scandium solubility limit in the dodecahedral sites of YSAG:Yb was found to be 66 ± 2 at.%. The limit of scandium solubility in octahedral sites depended upon the type of garnet-forming cations. The solubility limit for Sc 3+ decreased from 97.5 ± 0.5 to 68.5 ± 1 at.% with simultaneous increase of ytterbium content in the YSAG-YbSAG system. Therefore, the region of solid solutions existing with a garnet structure in the Al 2 O 3 -Sc 2 O 3 -Yb 2 O 3 -Y 2 O 3 system was determined. Samples having scandium in both dodecahedral and octahedral sites, which had a Sc 3+ content of~30 at.%, were synthesized as a precursor for optical ceramic production.

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Aluminum nitride films have been grown by plasma enhanced atomic layer deposition under self limiting growth and CVD like conditions. The films have been characterized by IR spectroscopy, ellipsome try, and Auger exposure spectroscopy. We have examined the influence of the deposition temperature, the reactor purge time after exposure to trimethylaluminum vapor, and the plasma exposure time on the growth rate and composition of the films. Under the deposition conditions studied, the growth rate ranged from 0.1 to 0.26 nm per cycle and the refractive index of the films was 1.52 to 1.98. We obtained films with an aluminum to nitrogen atomic ratio near unity.