Preparation conditions of \mathrm{A}_{2} \mathrm{MSbO}_{6} compounds. The data shown are as follows: Ionic radii in { }^{3}; \Delta \mathrm{r}=\left|r_{M^{3+}}-r_{S b^{5+}}\right|; tolerance factor; highest temperature of treatment; the detected impurities; symmetry of the crystal structure at room temperature and literature reference. PW stands for present work.
| Compound | I.R(Å) | \Delta \mathrm{r}(\AA) | t | S.T.(K) | Impurities | SG. at 300K | Ref. |
|---|---|---|---|---|---|---|---|
| \mathrm{Sr}_{2} \mathrm{NdSbO}_{6} | 0.983 | 0.383 | 0.914 | 1570 | P 2_{1} / n | PW | |
| \mathrm{Sr}_{2} \mathrm{EuSbO}_{6} | 0.947 | 0.347 | 0.921 | 1570 | P 2_{1} / n | PW | |
| \mathrm{Sr}_{2} \mathrm{GdSbO}_{6} | 0.938 | 0.338 | 0.923 | 1770 | \leq 1 \% \mathrm{Gd}_{2} \mathrm{O}_{3} | P 2_{1} / n | PW |
| \mathrm{Sr}_{2} \mathrm{DySbO}_{6} | 0.912 | 0.312 | 0.929 | 1770 | P 2_{1} / n | PW | |
| 1670 | P 2_{1} / n | 160 | |||||
| \mathrm{Sr}_{2} \mathrm{HoSbO}_{6} | 0.901 | 0.301 | 0.931 | 1770 | \leq 1 \% \mathrm{Ho}_{2} \mathrm{O}_{3} | P 2_{1} / n | PW |
| 1670 | P 2_{1} / n | 160 | |||||
| \mathrm{Sr}_{2} \mathrm{YSbO}_{6} | 0.900 | 0.300 | 0.931 | 1770 | P 2_{1} / n | PW | |
| 1545 | P 2_{1} / n | 161 | |||||
| 1370 | F m \overline{3} m | 162 | |||||
| \mathrm{Sr}_{2} \mathrm{ErSbO}_{6} | 0.890 | 0.290 | 0.934 | 1770 | P 2_{1} / n | PW | |
| \mathrm{Sr}_{2} \mathrm{TmSbO}_{6} | 0.880 | 0.280 | 0.936 | 1770 | \leq 1 \% \mathrm{Tm}_{2} \mathrm{O}_{3} | P 2_{1} / n | PW |
| \mathrm{Sr}_{2} \mathrm{YbSbO}_{6} | 0.868 | 0.268 | 0.938 | 1770 | \leq 1 \% \mathrm{Yb}_{2} \mathrm{O}_{3} | P 2_{1} / n | PW |