A precursor for Y 3 Al 5 O 12 was synthesized as a YAG sol by simply dissolving Y 2 O 3 powder in an alumina sol. Phasepure Y 3 Al 5 O 12 powder was obtained by precipitating the YAG sol with an aqueous dilute ammonia solution followed by calcination at 1100°C. TG/DTA analysis showed an exotherm at 938°C attributed to formation of YAG phase and weight loss of 44% at 1000°C. XRD and FT-IR analysis showed that phase-pure YAG can be formed through noncrystalline and metastable hexagonal YAlO 3 without forming either yttrium or aluminum formate intermediate.

A relaxor ferroelectric material, 0.9Pb(Mg 1/3 Nb 2/3 )O 3 -0.1PbTiO 3 (0.9PMN-0.1PT) with a pyrochlore-free phase, was prepared by using one-step calcination in the present study. The 0.9PMN-0.1PT powder with the pure perovskite phase was prepared successfully from a mixture of the PMN precursor and the crystalline PT by heating for 2 h at temperatures ≥750°C. The PMN precursor was synthesized by adding an aqueous Mg(NO 3 ) 2 solution, rather than MgO, to the alcoholic slurry of PbO and Nb 2 O 5 . The 0.9PMN-0.1PT powder sintered to >96% relative density via heat treatment for 2 h at temperatures of 900°-1200°C. The highest room-temperature dielectric constant ( rt ) was 24700 at 1 kHz for the samples that were sintered at 1100°C; however, the samples that were sintered at 900°C still had rt values of 22600 at 1 kHz.