Fe$_{5-\delta}$GeTe$_{2}$ Structure: A5BC2_hR8_160_5a_a_2a-001
| Prototype | Fe$_{5}$GeTe$_{2}$ |
| AFLOW prototype label | A5BC2_hR8_160_5a_a_2a-001 |
| ICSD | 130074 |
| Pearson symbol | hR8 |
| Space group number | 160 |
| Space group symbol | $R3m$ |
| AFLOW prototype command |
aflow --proto=A5BC2_hR8_160_5a_a_2a-001
--params=$a, \allowbreak c/a, \allowbreak x_{1}, \allowbreak x_{2}, \allowbreak x_{3}, \allowbreak x_{4}, \allowbreak x_{5}, \allowbreak x_{6}, \allowbreak x_{7}, \allowbreak x_{8}$ |
- The Fe-III and Fe-V sites are partially occupied, with 89.8% and 72.5% filling, respectively, so that $\delta = 0.377$. The iron atoms may also be replaced by nickel.
- (Stahl, 2018) found that the germanium atoms actually half-fill two sites, one with $z = 0.48493$ and the other with $z = 0.50663$. In the diagram these two sites will overlap, so we replaced them by a single averaged site.
- Hexagonal settings of this structure can be obtained with the option
--hex.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{\sqrt{3}}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}+x_{1} \, \mathbf{a}_{3}$ | = | $c x_{1} \,\mathbf{\hat{z}}$ | (1a) | Fe I |
| $\mathbf{B_{2}}$ | = | $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ | = | $c x_{2} \,\mathbf{\hat{z}}$ | (1a) | Fe II |
| $\mathbf{B_{3}}$ | = | $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+x_{3} \, \mathbf{a}_{3}$ | = | $c x_{3} \,\mathbf{\hat{z}}$ | (1a) | Fe III |
| $\mathbf{B_{4}}$ | = | $x_{4} \, \mathbf{a}_{1}+x_{4} \, \mathbf{a}_{2}+x_{4} \, \mathbf{a}_{3}$ | = | $c x_{4} \,\mathbf{\hat{z}}$ | (1a) | Fe IV |
| $\mathbf{B_{5}}$ | = | $x_{5} \, \mathbf{a}_{1}+x_{5} \, \mathbf{a}_{2}+x_{5} \, \mathbf{a}_{3}$ | = | $c x_{5} \,\mathbf{\hat{z}}$ | (1a) | Fe V |
| $\mathbf{B_{6}}$ | = | $x_{6} \, \mathbf{a}_{1}+x_{6} \, \mathbf{a}_{2}+x_{6} \, \mathbf{a}_{3}$ | = | $c x_{6} \,\mathbf{\hat{z}}$ | (1a) | Ge I |
| $\mathbf{B_{7}}$ | = | $x_{7} \, \mathbf{a}_{1}+x_{7} \, \mathbf{a}_{2}+x_{7} \, \mathbf{a}_{3}$ | = | $c x_{7} \,\mathbf{\hat{z}}$ | (1a) | Te I |
| $\mathbf{B_{8}}$ | = | $x_{8} \, \mathbf{a}_{1}+x_{8} \, \mathbf{a}_{2}+x_{8} \, \mathbf{a}_{3}$ | = | $c x_{8} \,\mathbf{\hat{z}}$ | (1a) | Te II |
References
- J. Stahl, E. Shlaen, and D. Johrendt, The van der Waals Ferromagnets Fe$_{5-\delta}$GeTe$_{2}$ and Fe$_{5-\delta-x}$Ni$_{x}$GeTe$_{2}$ - Crystal Structure, Stacking Faults, and Magnetic Properties, Z. Anorganische und Allgemeine Chemie 644, 1923–1929 (2018), doi:10.1002/zaac.201800456.
Prototype Generator
aflow --proto=A5BC2_hR8_160_5a_a_2a --params=$a,c/a,x_{1},x_{2},x_{3},x_{4},x_{5},x_{6},x_{7},x_{8}$