Phase stability of magnesium meta- and orthostannate has been examined in s
amples synthesized via the traditional solid-state reaction (SSR) and a nov
el self-heat-sustained (SHS) technique with two molar ratios of magnesium t
o tin (viz.. 1:1 and 2:1). The powder mixtures were calcined over a wide te
mperature-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 a
nd 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 met
hods. 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 Mg2
SnO4 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 por
osity could be achieved in SSR derived samples up on sintering up to 1600 d
egreesC, while some significant porosity was an interesting feature of the
SHS derived samples. Systematic microstructural evolution with the variatio
n of sintering conditions has been discussed. (C) 2001 Elsevier Science Ltd
and Techna S.r.l. All rights reserved.