Table 3. Relative Occupation of Tetrahedral and Octahedral Sites in γ-Ga2–xAlxO3 as Determined from the 27Al and 71Ga MAS NMR Spectra in Figure 7 and Overall Formulas (represented in defect spinel and AB2O4 notation) Derived from Them.
| 27Al NMR |
71Ga NMR |
formula |
||||
|---|---|---|---|---|---|---|
| x | % AlIV | % AlVI | % GaIV | % GaVI | defect spinel | AB2O4 |
| 0.0 | – | – | 26.8 | 73.2 | γ-(Ga0.535)tet[Ga1.465]octO3 | (Ga0.713)tet[Ga1.953]octO4 |
| 0.6 | 5.2 | 94.8 | 33.6 | 66.4 | γ-(Ga0.470Al0.031)tet[Ga0.930Al0.569]octO3 | (Ga0.626Al0.419)tet[Ga1.24Al0.759]octO4 |
| 1.0 | 7.7 | 92.3 | 39.3 | 60.7 | γ-(Ga0.393Al0.077)tet[Ga0.607Al0.923]octO3 | (Ga0.524Al0.103)tet[Ga0.809Al1.23]octO4 |
| 1.5 | 14.7 | 85.3 | 63.5 | 36.5 | γ-(Ga0.318Al0.221)tet[Ga0.183Al1.28]octO3 | (Ga0.424Al0.295)tet[Ga0.244Al1.706]octO4 |
| 1.8 | 19.4 | 80.6 | 61.8 | 38.2 | γ-(Ga0.124Al0.349)tet[Ga0.076Al1.45]octO3 | (Ga0.165Al0.465)tet[Ga0.101Al1.935]octO4 |