Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O Structure: A4B2C2DE2_tI22_139_2e_e_d_a_c-001
| Prototype | As$_{4}$Ba$_{2}$Fe$_{2}$OTi$_{2}$ |
| AFLOW prototype label | A4B2C2DE2_tI22_139_2e_e_d_a_c-001 |
| ICSD | 263018 |
| Pearson symbol | tI22 |
| Space group number | 139 |
| Space group symbol | $I4/mmm$ |
| AFLOW prototype command |
aflow --proto=A4B2C2DE2_tI22_139_2e_e_d_a_c-001
--params=$a, \allowbreak c/a, \allowbreak z_{4}, \allowbreak z_{5}, \allowbreak z_{6}$ |
- (Sun, 2012) consider this to be intergrown layers of BaFe$_{2}$As$_{2}$, which has the ThCr$_{2}$Si$_{2}$ structure, and BaTi$_{2}$As$_{2}$O.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | O I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}$ | (4c) | Ti I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}$ | (4c) | Ti I |
| $\mathbf{B_{4}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ | (4d) | Fe I |
| $\mathbf{B_{5}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{4}c \,\mathbf{\hat{z}}$ | (4d) | Fe I |
| $\mathbf{B_{6}}$ | = | $z_{4} \, \mathbf{a}_{1}+z_{4} \, \mathbf{a}_{2}$ | = | $c z_{4} \,\mathbf{\hat{z}}$ | (4e) | As I |
| $\mathbf{B_{7}}$ | = | $- z_{4} \, \mathbf{a}_{1}- z_{4} \, \mathbf{a}_{2}$ | = | $- c z_{4} \,\mathbf{\hat{z}}$ | (4e) | As I |
| $\mathbf{B_{8}}$ | = | $z_{5} \, \mathbf{a}_{1}+z_{5} \, \mathbf{a}_{2}$ | = | $c z_{5} \,\mathbf{\hat{z}}$ | (4e) | As II |
| $\mathbf{B_{9}}$ | = | $- z_{5} \, \mathbf{a}_{1}- z_{5} \, \mathbf{a}_{2}$ | = | $- c z_{5} \,\mathbf{\hat{z}}$ | (4e) | As II |
| $\mathbf{B_{10}}$ | = | $z_{6} \, \mathbf{a}_{1}+z_{6} \, \mathbf{a}_{2}$ | = | $c z_{6} \,\mathbf{\hat{z}}$ | (4e) | Ba I |
| $\mathbf{B_{11}}$ | = | $- z_{6} \, \mathbf{a}_{1}- z_{6} \, \mathbf{a}_{2}$ | = | $- c z_{6} \,\mathbf{\hat{z}}$ | (4e) | Ba I |
References
- Y.-L. Sun, H. Jiang, H.-F. Zhai, J.-K. Bao, W.-H. Jiao, Q. Tao, C.-Y. Shen, Y.-W. Z., Z.-A. Xu, and G.-H. Cao, Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O: A New Superconductor Containing Fe$_{2}$As$_{2}$ Layers and Ti$_{2}$O Sheets, J. Am. Chem. Soc. 134, 12893–12896 (2012), doi:10.1021/ja304315e.
Found in
- G. Wang, H. Zhang, L. Zhang, and C. Liu, The electronic structure and magnetism of BaTi$_{2}$Sb$_{2}$O, J. Appl. Phys. 113, 243904 (2013), doi:10.1063/1.4812489.
Prototype Generator
aflow --proto=A4B2C2DE2_tI22_139_2e_e_d_a_c --params=$a,c/a,z_{4},z_{5},z_{6}$