Class-I MV YBaFe$_{2}$O$_{5}$ Structure: AB2C5D_oP18_51_a_2f_2efj_c-001
| Prototype | BaFe$_{2}$O$_{5}$Y |
| AFLOW prototype label | AB2C5D_oP18_51_a_2f_2efj_c-001 |
| ICSD | 281202 |
| CCDC | 1721776 |
| Pearson symbol | oP18 |
| Space group number | 51 |
| Space group symbol | $Pmma$ |
| AFLOW prototype command |
aflow --proto=AB2C5D_oP18_51_a_2f_2efj_c-001
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak z_{3}, \allowbreak z_{4}, \allowbreak z_{5}, \allowbreak z_{6}, \allowbreak z_{7}, \allowbreak x_{8}, \allowbreak z_{8}$ |
Other compounds with this structure
DyBaFe$_{2}$O$_{5}$, EuBaCo$_{2}$O$_{5}$, EuBaFe$_{2}$O$_{5}$, GdBaFe$_{2}$O$_{5}$, TbBaFe$_{2}$O$_{5}$
- YBaFe$_{2}$O$_{5}$ is a mixed-valence compound which undergoes several magnetic transitions as it cools (Woodward, 2003):
- At high temperatures it is characterized as a Class-III MV (mixed valence) paramagnetic compound with equivalent iron atoms. It exists in a double perovskite structure in tetragonal space group $P4/mmm$ #123. This appears to be related to YBaCuFeO$_{5}$, but we have no experimental confirmation of that.
- Below 430K the system distorts into orthorhombic space group $Pmmm$ #47 and becomes antiferromagnetic. Below 335K the iron atoms become multivalent, splitting into Fe$^{2.5\pm\delta}$ sites. This is known as a Class-II MV structure.
- Below 308K the iron atoms are fully ordered with charges Fe$^{2+}$ and Fe$^{3+}$, forming a Class-I MV structure. The space group changes to $Pmma$ #51 (this structure).
- Here we use the data taken by (Woodward, 2003) at 20K.
- If we allow an uncertainty of 0.2Å in the atomic positions the space group changes to $P4/mmm$ and is nearly identical with the structure of YBaCuFeO$_{5}$ with the copper atoms removed and the iron sites fully occupied.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&b \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | Ba I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}$ | (2a) | Ba I |
| $\mathbf{B_{3}}$ | = | $\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2c) | Y I |
| $\mathbf{B_{4}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2c) | Y I |
| $\mathbf{B_{5}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+z_{3} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+c z_{3} \,\mathbf{\hat{z}}$ | (2e) | O I |
| $\mathbf{B_{6}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}- z_{3} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}- c z_{3} \,\mathbf{\hat{z}}$ | (2e) | O I |
| $\mathbf{B_{7}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+z_{4} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+c z_{4} \,\mathbf{\hat{z}}$ | (2e) | O II |
| $\mathbf{B_{8}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}- z_{4} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}- c z_{4} \,\mathbf{\hat{z}}$ | (2e) | O II |
| $\mathbf{B_{9}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{5} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{5} \,\mathbf{\hat{z}}$ | (2f) | Fe I |
| $\mathbf{B_{10}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{5} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{5} \,\mathbf{\hat{z}}$ | (2f) | Fe I |
| $\mathbf{B_{11}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{6} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{6} \,\mathbf{\hat{z}}$ | (2f) | Fe II |
| $\mathbf{B_{12}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{6} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{6} \,\mathbf{\hat{z}}$ | (2f) | Fe II |
| $\mathbf{B_{13}}$ | = | $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{7} \, \mathbf{a}_{3}$ | = | $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{7} \,\mathbf{\hat{z}}$ | (2f) | O III |
| $\mathbf{B_{14}}$ | = | $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{7} \, \mathbf{a}_{3}$ | = | $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{7} \,\mathbf{\hat{z}}$ | (2f) | O III |
| $\mathbf{B_{15}}$ | = | $x_{8} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{8} \, \mathbf{a}_{3}$ | = | $a x_{8} \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{8} \,\mathbf{\hat{z}}$ | (4j) | O IV |
| $\mathbf{B_{16}}$ | = | $- \left(x_{8} - \frac{1}{2}\right) \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+z_{8} \, \mathbf{a}_{3}$ | = | $- a \left(x_{8} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+c z_{8} \,\mathbf{\hat{z}}$ | (4j) | O IV |
| $\mathbf{B_{17}}$ | = | $- x_{8} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{8} \, \mathbf{a}_{3}$ | = | $- a x_{8} \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{8} \,\mathbf{\hat{z}}$ | (4j) | O IV |
| $\mathbf{B_{18}}$ | = | $\left(x_{8} + \frac{1}{2}\right) \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}- z_{8} \, \mathbf{a}_{3}$ | = | $a \left(x_{8} + \frac{1}{2}\right) \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}- c z_{8} \,\mathbf{\hat{z}}$ | (4j) | O IV |
References
- P. M. Woodward and P. Karen, Mixed Valence YBaFe$_{2}$O$_{5}$, Inorg. Chem. 42, 1121–1129 (2003), doi:10.1021/ic026022z.
First cited in
- N. Anderson, M. J. Mehl, H. Eckert, S. Divilov, X. Campilongo, S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 5. Submitted to Computational Materials Science (2026).
Geometry files
Prototype Generator
aflow --proto=AB2C5D_oP18_51_a_2f_2efj_c --params=$a,b/a,c/a,z_{3},z_{4},z_{5},z_{6},z_{7},x_{8},z_{8}$