REACTIVITY IN THE AL2O3-ALN-MGO SYSTEM - THE MGALON SPINEL PHASE

The conditions for obtaining spinel aluminium and magnesium oxynitride were examined in the temperature range 1400-1850-degrees-C into the d omain delimited by the spinel solid solutions: MgAl2O4-Al2O3 and AlON- Al2O3. The stud of some compositions having the same ratio N/Mg = 0.35 elaborated in different systems: AlN-MgAl2O4, AlN-MgO, AlON-MgO showe d the presence of intermediate spinels in which aluminium nitride or m agnesium oxide are dissolved when the temperature increases, giving th e MgAlON spinel. Some secondary reactions are observed under specific conditions. The lattice parameter evolution in regard to the compositi on has also been studied.