Microwave-induced reaction sintering of NiAl2O4

While the enormous increase in kinetics during the synthesis and sintering of complex ceramics in a microwave field is now well established, there are less examples where synthesis and sintering to high density have been demonstrated in one single step. In this communication, we report the simultaneous synthesis and sintering of NiAl2O4 from NiO + Al2O3 powder mixture in just 15 min in a 2.45-GHz microwave field. The "anisothermal reaction" condition that was achieved in a microwave field appears to be responsible for the observed enhancement in the reaction kinetics of NiAl2O4 formation. (C) 2002 Elsevier Science B.V. All rights reserved.