High Reactive MgO-Y2O3 Nanopowders via Microwave Combustion Method and Sintering Behavior.

To decrease the sintering temperature of MgO-Y2O3 composites to avoid undesired grain coarsening, high reactive MgO-Y2O3 nanopowders were synthesized via microwave combustion method. The degree of combustion was enhanced effectively by adding an extra oxidant ammonium nitrate. The as-synthesized MgO-Y2O3 nanopowders, ~18 nm in size, showed high specific surface area of 64.55 m2/g and low agglomeration. Relative density of 98% was obtained when sintered at a low sintering temperature of 1350°C. The high reactivity can be attributed to the lower activation energy Q (131.13 kJ/mol), compared with samples without extra oxidant (192.97 kJ/mol). [ABSTRACT FROM AUTHOR]