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

Andrew Chizmeshya, M. J. McKelvy, R. Sharma, Ray Carpenter, H. Bearat

Research output: Contribution to journalArticle

20 Citations (Scopus)

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 (∼160GPa). 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.

Original languageEnglish (US)
Pages (from-to)416-425
Number of pages10
JournalMaterials Chemistry and Physics
Volume77
Issue number2
DOIs
StatePublished - Jan 15 2003

Fingerprint

Magnesium Hydroxide
periclase
Compressibility
Hydroxyl Radical
Oxides
Lattice constants
Density functional theory
Solid solutions
density functional theory
Decomposition
decomposition
Chemical analysis
brucite
Experiments
breathing
Temperature
compressibility
lattice parameters
solid solutions
trends

Keywords

  • Computer simulation
  • Density functional theory
  • Intermediate phases
  • Mg(OH)
  • MgO
  • Oxyhydroxide
  • Reactivity

ASJC Scopus subject areas

  • Materials Chemistry

Cite this

Density functional theory study of the decomposition of Mg(OH)2 : A lamellar dehydroxylation model. / Chizmeshya, Andrew; McKelvy, M. J.; Sharma, R.; Carpenter, Ray; Bearat, H.

In: Materials Chemistry and Physics, Vol. 77, No. 2, 15.01.2003, p. 416-425.

Research output: Contribution to journalArticle

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