heated at 950°C in NaCl and at 1130°C in KCl. Bi4T3O12 reacts with NaCl at high temperatures
but does not with KCl. The NaCl-KCl salt cannot be used in the preparation of Bi4Ti3O12 at
high temperatures. Because the Aurivillius compounds with different m values have similar Xray
diffraction patterns, close examination of the pattern is necessary to ensure the formation
of the material with the desired composition (Sanson & Whatmore 2005).
The reactivity of an oxide with the salt often depends on the oxide chemical species. When
Li2SO4 is used in the preparation of BaFe12O19 from BaCO3 and Fe2O3, LiFe5O8 forms by the
following reaction; BaCO3+5Fe2O5+Li2SO4→2LiFe5O8+BaSO4+CO2 (Wickham, 1971). The
exchange reaction MgCO3+Li2SO4→MgSO4+Li2CO3 does not occur and MgFe2O4 is obtained
from MgCO3 and Fe2O3 in Li2SO4-Na2SO4