Ln3[SiON3]O (Ln = La, Ce, Pr) – Three Oxonitridosilicate Oxides with Crystal Structures Derived from the Anti-Perovskite Structure Type

Juliane Kechele (1) , Christian Schmolke (1) , Saskia Lupart (1) , Wolfgang Schnick (2)

1 Department Chemie und Biochemie
2 Department Chemie und Biochemie

The oxonitridosilicate oxides Ln3[SiON3]O with Ln = La, Ce, Pr were obtained by high-temperature syntheses (1450 - 1600 °C) in a radio-frequency furnace. The crystal structures were determined from single-crystal X-ray diffraction data and confirmed by Rietveld refinements. The compounds Ln3[SiON3]O crystallize in space group I4/mcm (La3[SiON3]O: a = 6.8224(10), c = 11.074(2) Å, Z = 4; R1 = 0.0240; Ce3[SiON3]O: a = 6.7233(10), c = 11.069(2) Å, Z = 4, R1 = 0.0234; Pr3[SiON3]O: a = 6.6979(9), c = 11.005(2) Å, Z = 4; R1 = 0.0156) and they were found to be isotypic with Gd3[SiON3]O, whose structure derives from the anti-perovskite structure type. In the crystal there are elongated OLn6-octahedra which are interconnected through common vertices. In the cavities of this network there are exclusively non-condensed SiON3 tetrahedra. 29Si solid-state NMR investigations, lattice energy calculations (MAPLE) and EDX measurements confirmed the crystal structure and the chemical compositions. For Ce3[SiON3]O, magnetic susceptibility measurements were carried out and the paramagnetic behavior with an experimental magnetic moment of 2.2 µB per cerium atom indicates Ce3+.

Mots clés: Physical Sciences

Juliane Kechele, Christian Schmolke, Saskia Lupart, Wolfgang Schnick. Ln3[SiON3]O (Ln = La, Ce, Pr) – Three Oxonitridosilicate Oxides with Crystal Structures Derived from the Anti-Perovskite Structure Type. Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, 2009, 636 (1), pp.176. ⟨10.1002/zaac.200900274⟩. ⟨hal-00507773⟩