SLNA, SODIUM LANTHANIDE ALUMINATES, MIXED BETA-ALUMINA-MAGNETOPLUMBITE MATERIALS

This paper reports the structural and spectroscopic investigations of SLNA sodium lanthanide aluminate; Ln equals La, Nd, La/Nd) with approximate composition 11. 5 Al//2O//3, 0. 65 Na//2O, 0. 5 Ln//2O//3. The compound belongs to the P6m2 space group and its structure can be described as a stacking of half cells of beta //N//a alumina and lanthanide aluminate with magnetoplumbite like structure. In this compound sodium ions behave as in beta alumina (ion exchange properties, ionic conductivity, excess of sodium ions). The EPR study of Nd**3** plus confirms the magnetoplumbite like environment of this ion in the structure. Partial substitution of Al//2O//3 by MgO or MgF//2 allows a dramatic reduction of the synthesis temperature of SLNA.