Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10637059 | Solid State Sciences | 2005 | 6 Pages |
Abstract
The structural development of apatite-type chlorellestadite was studied as a function of annealing time by Rietveld refinements based on X-ray powder diffraction data (Cu-Kα1). Annealing (900-1100â°C) in air of chlorellestadite with the unit cell content: Ca9(SiO4)3(SO4)3â
(1âx)CaCl2(xâ0) produced a nonstoichiometric phase (0⩽x⩽0.6), which then upon further heating decomposed into ternesite Ca5 (SiO4)2(SO4), anhydrite CaSO4 and lime CaO. Increasing the temperature caused a more rapid loss of CaCl2 and a more rapid onset of decomposition into the former phases. Crystal data of the chlorellestadite series: hexagonal symmetry, space group P63/m(0⩽x⩽0.6); and a=9.677Ã
, c=6.858Ã
for xâ0; as compared to a=9.561Ã
, c=6.895Ã
for xâ0.6. The results indicated that the chlorellestadite structure can accommodate an unusually high level of Schottky defects.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Simon Jegou Saint-Jean, Staffan Hansen,