There are a few papers on Zinc-Platinum Systems (e.g., Ref.1 and 2, which are also sited in Ref.3), but most of them are in German. However, there were few useful data published by Johnson and Dillon in their Research and Development Report (Ref.4):
$$
\bf{The \ structures \ of \ platinum-zinc \ intermetallic \ phases}\\
\begin{array}{l|l r r}
\hline
\text{Compound*} & \text{Crystal Class} & \text{Lattice Parameters, }\pu{pm} & \text{References} \\
\hline
\ce{PtZn} & \text{Cubic} & a = 1811.6 & 2 \\
\ce{PtZn8} & - & - & 2 \\
\ce{PtZn2} (\xi) & \text{Hexagonal} & a = 410, \ c = 274 & 2 \\
\ce{PtZn}\ (\nu) & \text{Tetragonal} & a = 403, \ c = 347 & 1 \ \& \ 2 \\
\ce{Pt3Zn} & \text{Cubic} & a = 389 & 2 \\
\hline
\end{array}\\
\text{*All phases have a range of composition.}$$
Nowotny et al. (Ref.2) determined the solubility of platinum in liquid zinc by thermal analysis. Their measurements cover the range of $\pu{688-869 ^\circ C}$ and are shown in following Table:
$$
\begin{array}{l r r r}
\hline
T, \ \pu{^\circ C} & \frac{1000}{T}, \ \pu{K-1} & \ce{Pt}, \ \text{weigh percent} & \ce{Pt}, \ \text{atom percent} \\
\hline
869 & 0.876 & 30.1 & 12.6 \\
825 & 0.911 & 23.2 & 9.2 \\
762 & 0.966 & 18.1 & 6.9 \\
728 & 0.999 & 14.8 & 5.5 \\
688 & 1.0404 & 9.8 & 3.5 \\
\hline
\end{array}\\
\text{*All phases have a range of composition.}$$
The direct measurements may be represented by the following empirical equations over the range of $\pu{675-875 ^\circ C}$ (Ref.4):
$$\log \left(a/o \ \ce{Pt}\right) = 3.881 - 3176T^{-1} \tag1$$
$$\log \left(w/o \ \ce{Pt}\right) = 3.917 - 2780T^{-1} \tag1$$
where $\left(a/o \ \ce{Pt}\right)$ is the atom percent platinum and $\left(w/o \ \ce{Pt}\right)$ is the weight percent platinum.
References:
- H. Nowotny, E. Bauer, and A. Stempfl, “Die Kristallstrukturen von PtZn, PtCd und PdCd (English Translation: Crystal Structures of PtZn, PtCd, and PdCd),” Monatshefte für Chemie 1950, 81(7), 1164-1164 (In German; DOI: https://doi.org/10.1007/BF00899370).
- H. Nowotny, E. Bauer, A. Stempfl, and H. Bittner, “Über die Systeme: Platin-Zink und Platin-Kadmium (English Translation: On the System: Platinum-Zinc and Platinum-Cadmium),” Monatshefte für Chemie 1952, 83(1), 221–236 (In German; DOI: https://doi.org/10.1007/BF00897822).
- Z. Moser, “The Pt-Zn (Platinum-Zinc) system,” Journal of Phase Equilibria 1991, 12, 439–443 (DOI: https://doi.org/10.1007/BF02645964).
- Irving Johnson and Ira G. Dillon, “The Solubility of Metals in Liquid Zinc,” USAEC Research and Development Report (Argonne National Laboratory, Argonne, IL), ANL-7083, pp. 78–79 (1965).
