Figure 1

Specular x-ray reflectivity vs momentum transfer for the quartz (100) surface in contact with deionized water and 200-ppm PTA at $p\mathrm{H}\sim 10$. Calculations (solid lines) are derived from nonlinear least-squares fits to the data. The vertical arrows indicate the selected $q$ positions at which the RAXR spectra were measured.Reuse & Permissions

Figure 2

RAXR spectra normalized with nonresonant reflectivity near the Pt $L_{\mathrm{I}\mathrm{I}\mathrm{I}}$ edge (11.564 keV) of the quartz(100)-PTA interface at selected momentum transfers. Lines represent calculations corresponding to the best-fit model (red thick lines) and two other models described in the text. The vertical lines indicate the energies noted in Fig. 3b. Data are offset vertically as indicated for clarification.Reuse & Permissions

Figure 3

(a) Derived resolution-broadened interfacial profiles [18] of quartz (100) surfaces in contact with deionized water and 200-ppm PTA at $p\mathrm{H}\sim 10$. The Pt-specific profile of adsorbed PTA is also shown. The peaks at $z<0\AA$ correspond to quartz lattice atoms, and the peak at $z\sim 1\AA$ corresponds to “adsorbed” water. (b) Derived $f_{\mathrm{P}\mathrm{t}}{}^{\prime }(E)$ and $f_{\mathrm{P}\mathrm{t}}{}^{\prime \prime }(E)$ of PTA. The vertical lines represent the positions of the minimum and the maximum of $f_{\mathrm{P}\mathrm{t}}{}^{\prime }(E)$ near the Pt $L_{\mathrm{I}\mathrm{I}\mathrm{I}}$ edge (at 11.564 and 11.570 keV, respectively) for the adsorbed PTA species. The relative difference of 6 eV corresponds to the width of the white-line ($\Gamma$) in $f_{\mathrm{P}\mathrm{t}}{}^{\prime \prime }(E)$ for the adsorbed Pt species.Reuse & Permissions