CuAu ($L1_{0}$) Structure: AB_tP2_123_a_d

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Prototype : CuAu
AFLOW prototype label : AB_tP2_123_a_d
Strukturbericht designation : $L1_{0}$
Pearson symbol : tP2
Space group number : 123
Space group symbol : $\mbox{P4/mmm}$
AFLOW prototype command : aflow --proto=AB_tP2_123_a_d
--params=
$a$,$c/a$


Other compounds with this structure

  • FePt, (Ni,Fe)Pt, (Cu,Fe)Pt, AgTi, AlTi, BiLi, BiNa, CoPt, FePd, FePt, GaTi, HgPt, HgTi, HgZr, InPu, IrMn, IrNb, IrV, MnNi, MnPt, MnRh, NiPt, PtV, PtZn, and RhTl

  • (Ewald, 1931) and later (Pearson, 1958) both doubled the unit cell and gave this structure the Pearson symbol tP4. This structure has the same AFLOW designation, AB_tP2_123_a_d, as $\delta$-CuTi ($L2_{a}$). The only difference in the structures is the $c/a$ ratio. $L1_{0}$ has $c/a \approx \sqrt{2}$, characteristitic of face-centered cubic ordering, while $L2_{a}$ has $c/a \approx 1$, a body-centered cubic-like system.

Simple Tetragonal primitive vectors:

\[ \begin{array}{ccc} \mathbf{a}_1 & = & a \, \mathbf{\hat{x}} \\ \mathbf{a}_2 & = & a \, \mathbf{\hat{y}} \\ \mathbf{a}_3 & = & c \, \mathbf{\hat{z}}\\ \end{array} \]

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & =&0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & =&0 \mathbf{\hat{x}} + 0 \mathbf{\hat{y}} + 0 \mathbf{\hat{z}} & \left(1a\right) & \mbox{Au} \\ \mathbf{B}_{2} & =&\frac12 \, \mathbf{a}_{1}+ \frac12 \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& =&\frac12 \, a \, \mathbf{\hat{x}}+ \frac12 \, a \, \mathbf{\hat{y}}+ \frac12 \, c \, \mathbf{\hat{z}}& \left(1d\right) & \mbox{Cu} \\ \end{array} \]

References

  • P. Bayliss, Revised Unit–Cell Dimensions, Space Group, and Chemical Formula of Some Metallic Materials, Can. Mineral. 28, 751–755 (1990).
  • P. P. Ewald and C. Hermann, eds., Strukturbericht 1913-1928, (Akademische Verlagsgesellschaft M. B. H., Leipzig, 1931).
  • W. B. Pearson, A Handbook of Lattice Spacings and Structures of Metals and Alloys, Volume 2, no. N.R.C. No. 8752 in International Series of Monographs on Metal Physics and Physical Metallurgy (Pergamon Press, Oxford, London, Edinburgh, New York, Paris, Frankfort, 1967).

Found in

  • R. T. Downs and M. Hall–Wallace, The American Mineralogist Crystal Structure Database, Am. Mineral. 88, 247–250 (2003).

Geometry files


Prototype Generator

aflow --proto=AB_tP2_123_a_d --params=

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