Title of article :
Density functional theory study of the decomposition of Mg(OH)2: a lamellar dehydroxylation model
Author/Authors :
A.V.G. Chizmeshya، نويسنده , , M.J. McKelvy، نويسنده , , R. Sharma، نويسنده , , R.W. Carpenter، نويسنده , , H. Bearat، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2003
Pages :
10
From page :
416
To page :
425
Abstract :
We present a density functional theory investigation of the decomposition of Mg(OH)2. Based on recent experiments indicating a lamellar dehydroxylation process we have calculated the energetics, elastic behavior and structural trends of a series of oxyhydroxide intermediates of composition Mgx+yOx(OH)2y representing a solid solution series between brucite (Mg(OH)2) and periclase (MgO). Using a variationally induced breathing (VIB) ionic approach we find that this broad range of lamellar oxyhydroxide intermediate materials becomes thermodynamically accessible at temperatures near 500 °C. The computed dehydroxylation dependence of the compressibility is found to vary dramatically with the initial formation of periclase-like oxide layers displaying an abrupt jump to a value near that of periclase (∼160 GPa). In contrast to this very non-linear behavior the basal plane lattice parameter a is found to exhibit a nearly linear (Vegard-like) dependence on hydroxyl content.
Keywords :
Mg(OH)2 , MGO , Density functional theory , computer simulation , Oxyhydroxide , Reactivity , Intermediate phases
Journal title :
Materials Chemistry and Physics
Serial Year :
2003
Journal title :
Materials Chemistry and Physics
Record number :
1060988
Link To Document :
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