Hybrid Microwave Sintering of Infrared Transparent Nano-Y3Al5O12 Synthesized by a Modified Combustion Technique

Infrared transparent ceramics found to have numerous civilian and defense applications. In the present work, Y3Al5O12 nanoparticles were synthesized by an auto-igniting modified single-step combustion method. The structure and morphology of the as-prepared powder revealed the phase purity and ultrafine nature of the powder having an average crystallite size of 16 nm and well-defined lattice planes. Coupling of the resistive and microwave heating at precise proportion leads to a sintered density of the powder with 99.3% of the theoretical density at a temperature as low as 1470 degrees C for a soaking duration of just 20 min. Marked reduction in grain size and the porosity was also observed for the hybrid sintered pellets. An average grain size of 167 nm was measured for the sintered pellets, which also showed a high transmittance of 80% in the UV-vis region and 82.5% in the mid-IR region.