MgAl2O4 synthetic spinel: cation and vacancy distribution as a function of temperature, from in situ neutron powder diffraction
-
A. Pavese
Neutron powder diffraction data collection has been carried out at BENSC (Berlin, D), on synthetic Mg0.94Al2.04O4 spinel, in the temperature range 300-1700 K, to investigate the intracrystalline cation and vacancy order-disorder (OD) reaction, which begins to be detectable at 944 K. The Rietveld method has been used in combination with advanced minimization techniques to determine the occupancy coefficients of magnesium, aluminum, and vacancies on the tetrahedral and octohedral sites. The temperature dependence of the cell parameter, of the T-O and M-O bond lengths, and of the oxygen u-coordinate are discussed in the light of the OD-reactions. The cation site partitioning has been interpreted as a function of temperature using the thermodynamic model of O´Neill and Navrotsky, whose parameters [α=30(2) and β=1(3) kJ/mol]are compared with earlier determinations from literature.
© 2015 Oldenbourg Wissenschaftsverlag GmbH, Rosenheimer Str. 145, 81671 München
Articles in the same Issue
- Determination of conduction paths of semiconducting electrons by bond-valence calculations
- On reliability of Rwp in structure modelling
- Self-intersecting three-periodic minimal surfaces forming two-periodic (flat) labyrinths
- Cd3B7O13(OH) a new synthetic hydroxy boracite
- Mixed alkali systems: Dietzels theorem, X-ray structure, hygroscopicity, and 29-Si MAS NMR of NaRbSi2O5 and NaCsSi2O5
- MgAl2O4 synthetic spinel: cation and vacancy distribution as a function of temperature, from in situ neutron powder diffraction
- Structure and spectroscopic properties of hydrogencarbonate containing alumosilicate sodalite and cancrinite
- The bond character of rutile type SiO2, GeO2 and SnO2 investigated by molecular orbital calculation
- X-ray diffraction study of bond character of rutile-type SiO2, GeO2 and SnO2
- Metallradien und Ionenradien
- Crystal structures of [N(C4H9)4][NbCl4OAlCl3] and [N(C3H7)4][NbCl6]
Articles in the same Issue
- Determination of conduction paths of semiconducting electrons by bond-valence calculations
- On reliability of Rwp in structure modelling
- Self-intersecting three-periodic minimal surfaces forming two-periodic (flat) labyrinths
- Cd3B7O13(OH) a new synthetic hydroxy boracite
- Mixed alkali systems: Dietzels theorem, X-ray structure, hygroscopicity, and 29-Si MAS NMR of NaRbSi2O5 and NaCsSi2O5
- MgAl2O4 synthetic spinel: cation and vacancy distribution as a function of temperature, from in situ neutron powder diffraction
- Structure and spectroscopic properties of hydrogencarbonate containing alumosilicate sodalite and cancrinite
- The bond character of rutile type SiO2, GeO2 and SnO2 investigated by molecular orbital calculation
- X-ray diffraction study of bond character of rutile-type SiO2, GeO2 and SnO2
- Metallradien und Ionenradien
- Crystal structures of [N(C4H9)4][NbCl4OAlCl3] and [N(C3H7)4][NbCl6]
