Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. a wide range of applications including refractory ceramics, optically transparent ceramic windows, armors. Its low dielectric permeability loss tangent enable its for integrated electronic devices, as well. In this paper, MgO Al2O3 powders were mixed in one-to-one molar ratio calcined at t...

0921-8831/$ see front matter 2011 The Society of doi:10.1016/j.apt.2011.11.004 ⇑ Corresponding author. Address: School of Metallu ing, University of Tehran, P.O. Box 14395-1491, Tehran fax: +98 21 88006076. E-mail address: [email protected] (S. Sheibani). In this paper, the possibility of mechano-chemical synthesis, as a single step process for preparation of nanostructured nickel aluminate sp...

The electronic structure of zinc aluminate (ZnAl2O4) and that of zinc gallate (ZnGa2O4) were studied by the self-consistent tight-binding linearized muffin-tin orbital method with the atomic sphere approximation. The calculated results predict these zinc-based spinel oxides to be direct-gap materials. The direct gap at 0 is found to be 4.11 eV for ZnAl2O4 and 2.79 eV for ZnGa2O4. With reference...

Transparent polycrystalline spinel ceramic was fabricated without any sintering aids by spark plasma sintering method of a mixture of Al2O3 and MgO powders for only 10min soak at 1250°C. Densification, microstructure and optical transparency of spinel were examined. The spinel exhibits an in-line transmission of 55% for a visible-wavelength of 470nm and high hardness value of 2040 HV.