The effect of Al2O3 doping on grain growth of Y2O3-MgO nanocomposite ceramics

In this study, Al 2 O 3 -doped Y 2 O 3 -MgO nanocomposite ceramics were synthesized to inhibit abnormal grain growth. Y 2 O 3 -MgO nanopowders were synthesized using a sol-gel combustion approach. Two distinct Al 2 O 3 doping methods were employed: aluminum nitrate doping during the solution preparation stage and aluminum isopropoxide doping during the ball-milling stage of powder preparation processing. This study presents a comparative analysis of the effect of two doping methods on the performance and microstructure of ceramics. Doping during the solution preparation process can provide a more homogeneous distribution of Al 2 O 3 , which facilitated the formation of a minor Y 4 Al 2 O 9 phase. This tertiary phase effectively inhibited abnormal grain growth and improved mid-infrared transmittance. However, Al-O bonds cause a blue shift of transmission cut-off edge and an increase of emissivity, though the practical consequences for device performance require further investigation.