The influence of synthesis conditions on the formation of yttrium aluminum garnet (YAG) powders starting from the same solution precursors was investigated by employing a citrate-nitrate gel combustion process and a precursor plasma spraying technique. YAG powders were formed at ≥500°C, through the citrate-nitrate gel combustion process, without any intermediate phase formation. Time-resolved x-ray experiments were performed for the first time on these citrate-nitrate precursor materials to understand their mode of decomposition. The in situ data confirmed a single-step conversion to YAG from the precursor powder without any intermediate phase formation. Ex situ experiments also produced similar results. However, the use of the same citrate-nitrate precursor solution as a liquid feedstock material in the precursor plasma spraying technique revealed an entirely different transformation mechanism to YAG through intermediate phases like H-YAlO3 and O-YAlO3.
Bibliographical noteFunding Information:
This work was supported by the Materials Research Science and Engineering Center (MRSEC) program of the National Science Foundation to the Center for Thermal Spray Research (CTSR) under Award No. DMR-0080021. P.S.D. was on leave of absence from Central Glass and Ceramic Research Institute, Calcutta, India. The work at NSLS X7B was supported under contract DE-AC02-98CH10886 with the United States Department of Energy by its Division of Chemical Sciences, Office of Basic Energy Research.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering