Mg2SnO4 ceramics I.: Synthesis-processing-microstructure correlation

Phase stability of magnesium meta- and orthostannate has been examined in samples synthesized via the traditional solid-state reaction (SSR) and a novel self-heat-sustained (SHS) technique with two molar ratios of magnesium to tin (viz.. 1:1 and 2:1). The powder mixtures were calcined over a wide temperature-time (T-t) span ranging from 600 to 1300 degreesC and 3 to 72 h. The powders obtained from the two preparative methods have been processed and sintered under identical conditions. In the 2:1 molar mixtures, Mg2SnO4 has been formed as a single phase up on calcination in both SRR and SHS methods. This phase remained the only compound in the sintered bodies as well. In the 1:1 composition, the ultimate reaction product was a mixture of Mg2SnO4 and SnO2. Both SSR and SHS techniques with 2:1 molar mixture yielded a single phase Mg2SnO4 in the sintered compacts. Compacts with near zero porosity could be achieved in SSR derived samples up on sintering up to 1600 degreesC, while some significant porosity was an interesting feature of the SHS derived samples. Systematic microstructural evolution with the variation of sintering conditions has been discussed. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights reserved.