Results 171 to 180 of about 3,718 (215)

Shock effects in MgAl2O4-spinel

Physics and Chemistry of Minerals, 1983
Shock 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, Wolfgang Friedrich M�ller, Ulrich Hornemann   +2 more
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Effect of additives on the sintering of MgAl2O4

Journal of Alloys and Compounds, 2014
Abstract The effect of additives on the densification of stoichiometric spinel was investigated. SiO 2 , CaCO 3 and TiO 2 are used as additives to spinel composition in the range of 1–4 wt%. Densification behavior is investigated by dilatometry measurement and the sintered body is characterized in terms of microstructure, phase formation and change
Taehyung Kim, Donghyun Kim, Shinhoo Kang
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Lattice vibrations of MgAl2O4 spinel

Journal of Physics and Chemistry of Solids, 1973
Abstract 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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Fracture of single crystal MgAl2O4

Journal of Materials Science, 1980
The fracture of single crystal, stoichiometric MgAl2O4 spinel, was investigated for the (1 0 0), (1 1 0), and (1 1 1) from room temperature to 1500° C. Two regions of fracture behaviour were observed; a low temperature elastic region where K lc decreased with increasing temperature, and an elevated temperature region where K lc increased rapidly with ...
R. L. Stewart, R. C. Bradt
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On Infrared Intensities of Spinel, MgAl2O4

Bulletin of the Chemical Society of Japan, 2005
Abstract 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, Yuichi Hayashi, Yoshiyuki Morioka   +2 more
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Magnesium Aluminum Spinel (MgAl2O4)

1997
Publisher 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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Comparative studies on structural and luminescent properties of Eu3+:MgAl2O4 and Eu3+/Na+:MgAl2O4 nanopowders and nanoceramics

Optical Materials, 2012
Abstract Transparent Eu3+ doped MgAl2O4 and Eu3+/Na+ co-doped MgAl2O4 nanoceramics have been obtained by a low-temperature high-pressure (LTHP) sintering process using crystalline powders prepared by sol–gel method. Structural properties have been studied by X-ray diffraction (XRD) and analyzed by Rietveld method.
R.J. Wiglusz, T. Grzyb, A. Lukowiak, P. Głuchowski, S. Lis, W. Strek   +5 more
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Effects of neutron-irradiation on MgAl2O4 and Al203

Journal of Nuclear Materials, 1986
Specimens of MgAl 2 O 4 and Al 2 0 3 were irradiated to a neutron fluence of approximately 2×10 26 n/m 2 , E > 0.1 MeV at 660 K. Tensile strength was seen to decrease by 25.6% for Al 2 O 3 and to increase by 24.4% for MgAl 2 O 4 . Density measurements revealed that Al 2 O 3 swelled by 3.22% while MgAl 2 O 4 densified slightly (0.316%).
D.S. Tucker, T. Zocco, C.D. Kise, J.C. Kennedy   +3 more
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Compression creep of Si3N4/MgAl2O4 alloys

Journal of Materials Science, 1990
The compression creep behaviour in air of pressureless sintered MgAl2O4-doped Si3N4 was studied at temperatures between 1473 and 1593 K, and under stresses between 50 and 300 M Pa. The variation of strain rate with stress and temperature was analysed to determine the stress exponent and the activation energy.
J. Crampon, R. Duclos, N. Rakotoharisoa
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Magnesium Aluminate (MgAl2O4) by XPS

Surface Science Spectra, 1994
The XPS spectra of materials containing both magnesium and aluminum can exhibit a number of spectral artifacts when using a Mg Kα x-ray source. These artifacts are easily observed in XPS spectra of magnesium aluminate (MgAl2O4, also known as magnesium aluminum oxide), which are presented in this article. For example, the Al 2p peak is overlapped by the
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