Rhombohedral Delafossite (CuFeO2) Structure : ABC2_hR4_166_a_b_c

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Prototype : CuFeO2
AFLOW prototype label : ABC2_hR4_166_a_b_c
Strukturbericht designation : None
Pearson symbol : hR4
Space group number : 166
Space group symbol : $R\bar{3}m$
AFLOW prototype command : aflow --proto=ABC2_hR4_166_a_b_c
--params=
$a$,$c/a$,$x_{3}$


Other compounds with this structure

  • AgAlO2, AgCoO2, AgCrO2, AgFeO2, AgGaO2, AgInO2, AgNiO2, AgRhO2, AgScO2, AgTlO2, CuAlO2, CuCoO2, CuCrO2, CuEuO2, CuGaO2, CuInO2, CuLaO2, CuRhO2, CuScO2, CuYO2, PdCoO2, PdCrO2, PdRhO2, and PtCoO2

  • Delafossite appears in two forms which differ in the stacking of the layers: rhombohedral, shown here, and hexagonal, prototype CuAlO2. Most of the compounds found in the hexagonal phase can also be found in the rhombohedral structure (Marquardt, 2006).
  • Rhombohedral delafossite has the same AFLOW label, ABC2_hR4_166_a_b_c, as caswellsilverite $F5_{1}$. The difference in the internal parameter $z_{3}$ causes a large change in the bonding of the two crystals, so we present them as different structures.

Rhombohedral primitive vectors:

\[ \begin{array}{ccc} \mathbf{a}_1 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \mathbf{a}_2 & = & \frac{1}{\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \mathbf{a}_3 & = & - \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \end{array} \]

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & = & 0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & = & 0 \, \mathbf{\hat{x}} + 0 \, \mathbf{\hat{y}} + 0 \, \mathbf{\hat{z}} & \left(1a\right) & \mbox{Cu} \\ \mathbf{B}_{2} & = & \frac{1}{2} \, \mathbf{a}_{1} + \frac{1}{2} \, \mathbf{a}_{2} + \frac{1}{2} \, \mathbf{a}_{3} & = & \frac{1}{2}c \, \mathbf{\hat{z}} & \left(1b\right) & \mbox{Fe} \\ \mathbf{B}_{3} & = & x_{3} \, \mathbf{a}_{1} + x_{3} \, \mathbf{a}_{2} + x_{3} \, \mathbf{a}_{3} & = & x_{3}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{O} \\ \mathbf{B}_{4} & = & -x_{3} \, \mathbf{a}_{1}-x_{3} \, \mathbf{a}_{2}-x_{3} \, \mathbf{a}_{3} & = & -x_{3}c \, \mathbf{\hat{z}} & \left(2c\right) & \mbox{O} \\ \end{array} \]

References

  • C. T. Prewitt, R. D. Shannon, and D. B. Rogers, Chemistry of noble metal oxides. II. Crystal structures of platinum cobalt dioxide, palladium cobalt dioxide, coppper iron dioxide, and silver iron dioxide, Inorg. Chem. 10, 719–723 (1971), doi:10.1021/ic50098a012.

Found in

  • M. A. Marquardt, N. A. Ashmore, and D. P. Cann, Crystal chemistry and electrical properties of the delafossite structure, Thin Solid Films 496, 146–156 (2006), doi:10.1016/j.tsf.2005.08.316.

Geometry files


Prototype Generator

aflow --proto=ABC2_hR4_166_a_b_c --params=

Species:

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