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Non-stoichiometry in MgAl2O4spinel
Philosophical Magazine, 2010 Stoichiometric magnesium aluminate spinel, MgAl2O4, contains equimolar proportions of Al2O3 and MgO. Spinel can, however, exhibit significant deviations from this stoichiometric composition.
Roger Smith, T E Mitchell
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Shock effects in MgAl2O4-spinel
Physics and Chemistry of Minerals, 1983Shock recovery experiments on synthetic MgAl2O4-spinel samples in the pressure range 25.5 to 50.5 GPa have been performed in order to examine the effects of shock waves on this material. The shocked samples were subsequently studied in the transmission electron microscope.
Helmut Sch�fer +2 more
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Lattice vibrations of MgAl2O4 spinel
Journal of Physics and Chemistry of Solids, 1973Abstract Raman spectra have been measured on oriented single crystals of MgAl2O4 spinel. The fundamental frequencies are A1g = 772, Eg = 410, and T2g = 671, 492 and 311 cm−1. A Kramers-Kronig analysis of the reflectance spectrum of spinel yields the i. r. -active vibrations T1u = 670, 485, 428 and 305 cm−1.
M.P. O'Horo, A.L. Frisillo, W.B. White
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On Infrared Intensities of Spinel, MgAl2O4
Bulletin of the Chemical Society of Japan, 2005Abstract In spinel (MgAl2O4), the strongest infrared band at 485 cm−1 shows less LO–TO splitting than the medium band at 670 cm−1. This unexpected relationship is explained in terms of the vibrational coupling of these TO modes. A new manner for evaluating the LO mode is proposed.
Isao Kanesaka +2 more
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New synthesis methods of MgAl2O4 spinel
Journal of the European Ceramic Society, 2007Abstract The paper presents a study concerning the influence of the precursors upon the synthesis temperature, particle size and morphology of the MgAl2O4 spinel. With this view there have been used by comparison three synthesis methods: thermal conversion of the heteropolynuclear complex combination resulted from the oxidation reaction of 1,2 ...
C. Păcurariu +5 more
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An orthorhombic chromium-center in the spinel MgAl2O4
Journal of Physics and Chemistry of Solids, 1973Abstract In Cr-doped MgAl 2 O 4 most of the Cr 3+ -ions occupy normal B -sites. In addition to this axial center we report here the presence of an orthorhombic Cr 3+ -center. The ESR-spectra of this new center can be described by the spin Hamiltonian: ℋ = D [ S z 2 − 1 3 S ( S + 1 ) ] + g x β H x S x
H. Van den Boom, J.C.M. Henning
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Magnesium Aluminum Spinel (MgAl2O4)
1997Publisher Summary Magnesium aluminum spinel (MgAl2O4) is a face-centered cubic material, the prototype for the spinel structural family, which includes binary oxides, sulfides, and selenides. The space group is Fd3m, unit cell length is 0.8084 nm, and the unit cell has eight formula units.
WILLIAM J. TROPF, MICHAEL E. THOMAS
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Low temperature synthesis of spinel (MgAl2O4)
Materials Letters, 1997Spinel (MgAl2O4) is prepared by a combined gelation-precipitation process from a mixed solution of sulphates of aluminium and magnesium. X-ray diffraction of gel samples calcined at different temperatures shows that a spinel-like phase starts forming at 600 °C and complete conversion is obtained at 1000 °C in 1 h.
Vinay Kumar Singh, Rakesh Kumar Sinha
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Cathodoluminescence of Mn2+ centers in MgAl2O4 spinels
Journal of Luminescence, 1990Abstract MgAl 2 O 4 :Mn spinels containing between 0 and 8% Mn by weight were prepared (a) by growth from an induction melt, and (b) by Mn + implantation into nonstoichiometric spinel crystals. Cathodolumenescence brightness measurements (520 nm emission band) were made as a function of Mn concentration on both (a) and (b), revealing increasing ...
R. Mlcak, A.H. Kitai
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Synthesis and characterization of MgAl2O4 spinel nanowires
Journal of Materials Chemistry, 2003MgAl2O4 spinel nanowires have been synthesized on an alumina substrate by reaction of magnesium oxide powders with graphite at 1350 °C in a flowing argon atmosphere. Transmission electron microscopy (TEM) images show that they have a diameter of 50–120 nm, and a length up to 500 micrometers.
Xingcai C. Wu +3 more
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