## 2 Results and Discussion
We can therefore conclude that the A-XRD analysis and this treatment of its data catches, at least semi-quantitatively, the changes in the morphology (size) and composition of the MNPs of these bimetallic systems as the Pd/Au ratio is varied. The same conclusion can be drawn with a similar approach but taking a different point of view. In fact, the population of the phases can easily be adjusted to match the experimental overall atomic (molar) Pd/Au ratio, while keeping at each edge the same values of D and a reported in Table 1 for each phase. These will be hereafter referred to as the \"metal-ratio adjusted populations\" (MAPs). With the exception of the data from the Pd edge of P50, this adjustment requires a large relative change in the population of the phase A, a small one, if any, in the population of phase B, and an almost negligible one in the population of phase C (Table 3). This is not unexpected, because phases A and C contain, by far and large, the smallest and the largest number of MNPs. It can also be appreciated that for P50 the N\({}_{\text{Pd}}\)/N\({}_{\text{Au}}\) value is much less sensitive to the population adjustment in comparison with P75. This and the large difference in the N\({}_{\text{Pd}}\)/N\({}_{\text{Au}}\) values of P75 at the Pd and the Au edges (Table 2, line 6) probably arise by the high degree of segregation of the metals in this specimen. Whereas gold is comparatively more evenly distributed among the phases in P50, in P75, an estimated 75% to 85% of all the gold atoms are concentrated in phase A. The above results show that a reliable estimate of the population of the phases and of the composition and size of their MNPs can be achieved with A-XRD analysis. This forms the basis to evaluate the relative contribution of each phase to the metal surface, which might be relevant to the catalytic behavior of these materials. Figures 4 and 5 illustrate the relative surface area of the nanostructured metallic phases. It can be appreciated that for both P50 and P75, the surface distribution among the phases turned out to be the same (in spite of some discrepancies for phase A), whatever starting set of data (Pd or Au edge, VAPs, or MAPs) were employed. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**\#**} & \multicolumn{2}{c}{**Cat**} & \multicolumn{2}{c}{**P50**} & \multicolumn{2}{c}{**P75**} & \multicolumn{2}{c}{**P75**} \\ \hline  & \multicolumn{2}{c}{**Edge**} & \multicolumn{2}{c}{**Pd**} & \multicolumn{2}{c}{**Au**} & \multicolumn{2}{c}{**Pd**} & \multicolumn{2}{c}{**Au**} & \multicolumn{2}{c}{**Pd**} & \multicolumn{2}{c}{**Au**} \\ \hline  & \multicolumn{2}{c}{**Phase**} & **A** & **B** & **C** & **A** & **B** & **C** & **A** & **B** & **C** & **A** & **B** & **C** & **A** & **B** & **C** \\ \hline
1 & V\({}_{\text{NaP}}\) (nm\({}^{3}\)) & 696.91 & 18.82 & 0.90 & 696.91 & 17.16 & 1.15 & 2026.27 & 102.16 & 0.52 & 2144.66 & 82.45 & 0.70 \\
2 & N\({}_{\text{NaP}}\) & 415.01 & 1140 & 61 & 41285 & 1053 & 76 & 119.601 & 6385 & 35 & 127,065 & 5133 & 46 \\
3 & P\({}_{\text{NaP}}\) (ppm) & 261 & 184.17 & 981.92 & 182 & 208.24 & 978.93 & 72 & 338 & 999.90 & 47 & 369 & 999.583 \\
4 & N\({}_{\text{NaP}}\)\({}^{10.7}\) & 1.01 & 1.68 & 0.51 & 0.72 & 1.89 & 0.65 & 1.21 & 0.20 & 0.055 & 0.70 & 0.15 & 0.006 \\
5 & N\({}_{\text{NaP}}\)\({}^{10.7}\) & 0.08 & 0.39 & 5.46 & 0.03 & 0.31 & 6.78 & 0.027 & 0.10 & 4.94 & 0.02 & 0.08 & 5.558 \\
6 & N\({}_{\text{NaP}}\)(N\({}_{\text{Na}}\) & \(7.9\times 10^{-2}\) & 0.23 & 10.7 & 4.2\times 10^{-2}\) & 0.16 & 10.4 & 5.8\(\times 10^{-3}\) & 0.50 & 9.9\(\times 10^{2}\) & 2.8\(\times 10^{-2}\) & 0.53 & 9.3\(\times 10^{2}\) \\ \hline
7 & N\({}_{\text{NaP}}\)/N\({}_{\text{Na}}\) (overall) & 1.86 & & 2.19 & & & 3.56 & & & & & & & \\ \end{tabular}
\end{table}