^{1}and J. R. Manson

^{1,a)}

### Abstract

Newly available experimental data for the scattering of argon, neon, and xenon atoms from molten gallium, indium, and bismuth surfaces are compared to calculations with classical scattering theory. The results of the theory are in reasonable agreement with observed energy-resolved spectra taken at fixed angles, with in-plane angular distributions, and with the first available out-of-plane angular distribution spectra for these systems. For all three of the rare gases, scattering from liquid Ga required the use of an effective surface mass equal to 1.65 times the mass of a single Ga atom. The need for a larger effective mass has been noted previously for scattering and is indicative of collective effects in the liquid Ga. Comparisons with data taken at low incident energies enable estimates of the physisorption well depth in the interaction potentials for many of the gas-metal combinations.

We would like to thank G. M. Nathanson, Jason Morgan, and David Castro for helpful discussions and for making their data available to us. This work was supported by the U.S. Department of Energy under Grant No. DE-FG02-98ER45704.

I. INTRODUCTION

II. THEORY

III. COMPARISON WITH EXPERIMENT

A. Argon on gallium

B. Neon and xenon on gallium

C. Argon on bismuth

D. Argon on indium

E. Neon on indium

IV. DISCUSSION AND CONCLUSIONS

### Key Topics

- Angular distribution
- 30.0
- Surface scattering
- 29.0
- Liquid surfaces
- 22.0
- Atom scattering
- 17.0
- Scattering measurements
- 17.0

## Figures

Energy-resolved spectrum of Ar scattered from a liquid Ga surface with a temperature of , , and . Experimental data are circles, the total scattering calculation is the solid curve, the single scattering is the dashed curve, and the double scattering is the dotted curve.

Energy-resolved spectrum of Ar scattered from a liquid Ga surface with a temperature of , , and . Experimental data are circles, the total scattering calculation is the solid curve, the single scattering is the dashed curve, and the double scattering is the dotted curve.

Temperature dependence of the squared FWHM for Ar scattered from a liquid Ga surface with and . The solid line (—) is the Gaussian approximation of Eq. (5) and the dashed line is the trajectory approximation. Data are circles, the calculated single scatterings are the open squares and the total scatterings are the solid squares. The dotted line is a linear fit to the total scattering (i.e., to the solid squares) with a constant offset added for comparison with the slope of the data.

Temperature dependence of the squared FWHM for Ar scattered from a liquid Ga surface with and . The solid line (—) is the Gaussian approximation of Eq. (5) and the dashed line is the trajectory approximation. Data are circles, the calculated single scatterings are the open squares and the total scatterings are the solid squares. The dotted line is a linear fit to the total scattering (i.e., to the solid squares) with a constant offset added for comparison with the slope of the data.

In-plane (left panels) and out-of-plane (right panels) angular distributions for with and for three different values of surface temperature: [(a) and (d)] , [(b) and (e)] , and [(c) and (f)] . Data are circles and calculations are the solid curves.

In-plane (left panels) and out-of-plane (right panels) angular distributions for with and for three different values of surface temperature: [(a) and (d)] , [(b) and (e)] , and [(c) and (f)] . Data are circles and calculations are the solid curves.

In-plane angular distribution for with and for a surface temperature of . Data are open circles; data with fractions of the equilibrium cosine distribution subtracted are filled circles. Theoretical calculations are the solid curve.

In-plane angular distribution for with and for a surface temperature of . Data are open circles; data with fractions of the equilibrium cosine distribution subtracted are filled circles. Theoretical calculations are the solid curve.

Energy-resolved spectra for for , , and . Calculations for are the dashed curve, calculations for are the solid curve, and data are open circles.

Energy-resolved spectra for for , , and . Calculations for are the dashed curve, calculations for are the solid curve, and data are open circles.

In-plane angular distribution spectrum for at a surface temperature with and . Data are circles and the calculation is the solid curve.

In-plane angular distribution spectrum for at a surface temperature with and . Data are circles and the calculation is the solid curve.

In-plane angular distribution spectrum for for surface temperature with , , , and an interaction well depth of . Data, after subtraction of an equilibrium component, are shown as filled circles, and the calculation is the solid curve.

In-plane angular distribution spectrum for for surface temperature with , , , and an interaction well depth of . Data, after subtraction of an equilibrium component, are shown as filled circles, and the calculation is the solid curve.

In-plane, out-of-plane, and energy-resolved spectra for : (a) In-plane spectra angular distribution with , , and . (b) Out-of-plane angular distribution for , , and . (c) Energy-resolved spectrum for , , and , with the theory curves as in Fig. 1. Data are open circles.

In-plane, out-of-plane, and energy-resolved spectra for : (a) In-plane spectra angular distribution with , , and . (b) Out-of-plane angular distribution for , , and . (c) Energy-resolved spectrum for , , and , with the theory curves as in Fig. 1. Data are open circles.

In-plane and energy-resolved spectra for for and : (a) in-plane angular distribution for ; (b) energy-resolved spectrum for . Data are circles. Theory with well depth zero are the dashed curves, theory with well depth are the solid curves, and theory with well depth are the dotted curves. A Knudsen distribution is shown in each panel as the dash-dot curve.

In-plane and energy-resolved spectra for for and : (a) in-plane angular distribution for ; (b) energy-resolved spectrum for . Data are circles. Theory with well depth zero are the dashed curves, theory with well depth are the solid curves, and theory with well depth are the dotted curves. A Knudsen distribution is shown in each panel as the dash-dot curve.

: (a) in-plane angular distribution and (b) out-of-plane angular distribution, both for , , and . (c) Energy-resolved spectrum for , , and .

: (a) in-plane angular distribution and (b) out-of-plane angular distribution, both for , , and . (c) Energy-resolved spectrum for , , and .

Angular distributions for for , , and three different incident energies of (a) , (b) , and (c) . On the left are in-plane angular distributions and on the right are out-of-plane distributions measured starting from the in-plane polar angle . Data are open circles and calculations are solid curves.

Angular distributions for for , , and three different incident energies of (a) , (b) , and (c) . On the left are in-plane angular distributions and on the right are out-of-plane distributions measured starting from the in-plane polar angle . Data are open circles and calculations are solid curves.

distributions for , , and . (a) In-plane angular distribution, (b) out-of-plane angular distribution, and (c) energy-resolved spectrum for , showing calculation for with a dashed curve; all other calculations are for shown as solid curves.

distributions for , , and . (a) In-plane angular distribution, (b) out-of-plane angular distribution, and (c) energy-resolved spectrum for , showing calculation for with a dashed curve; all other calculations are for shown as solid curves.

## Tables

Table of well depths that could be estimated by comparisons with the data, in dimensions of meV.

Table of well depths that could be estimated by comparisons with the data, in dimensions of meV.

Article metrics loading...

Full text loading...

Commenting has been disabled for this content