Density functional theory study of the decomposition of Mg(OH)2: a lamellar dehydroxylation model

Autor:	Michael J. McKelvy, Renu Sharma, Hamdallah Bearat, Andrew Chizmeshya, Ray Carpenter
Rok vydání:	2003
Předmět:	Brucite Oxide Ionic bonding engineering.material Condensed Matter Physics chemistry.chemical_compound Lattice constant chemistry engineering Physical chemistry General Materials Science Lamellar structure Density functional theory Periclase Chemical decomposition
Zdroj:	Materials Chemistry and Physics. 77:416-425
ISSN:	0254-0584
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e95c3ad2b0e832bd1c39869d247419c7 https://doi.org/10.1016/s0254-0584(02)00020-2 Zobrazit plný text záznamu Full Text from ScienceDirect