Atom-resolved non-contact atomic force microscopy (NC-AFM) studies of the magnesium aluminate (MgAl(2)O(4)) surface have revealed that, contrary to expectations, the (100) surface is terminated by an aluminum and oxygen layer. Theoretical studies have suggested that hydrogen plays a strong role in stabilizing this surface through the formation of surface hydroxyl groups, but the previous studie...

The radiation damage produced by energetic heavy ions in several ceramic oxides was characterized by different methods: thermoluminescence, optical absorption, fluorescence and electron paramagnetic resonance. Following ion irradiation, the thermoluminescence intensity of all the samples is shown to decrease. This can be related to the observed rise of the optical absorption in the whole wavele...

Based on high-resolution noncontact atomic force microscopy (NC-AFM) experiments we reveal a detailed structural model of the polar (111) surface of the insulating ternary metal oxide, MgAl(2)O(4) (spinel). NC-AFM images reveal a 6√3×6√3R30° superstructure on the surface consisting of patches with the original oxygen-terminated MgAl(2)O(4)(111) surface interrupted by oxygen-deficient areas. The...

Low-cost magnesium aluminate spinel ceramics were successfully synthesized from the minerals of magnesite(M) and bauxite(B) via one-step sintering method. The effect ratio bauxite to magnesite on phase evolution, microstructure, as well mechanical properties was thoroughly investigated. structural analysis indicated that Mg2+ or Al3+ ions dissolved in lattice formed Mg-rich/Al-rich MgAl2O4 (MA)...

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.