Volume 110, Issue 5, 01 February 1999
Index of content:
110(1999); http://dx.doi.org/10.1063/1.477997View Description Hide Description
The light absorption of a solid sample in the 8.5 μm region is measured via cavity ring down (CRD) absorption spectroscopy, using a free electron laser(FEL) as a source of widely tunable infrared (IR) radiation. A 3 mm thick zinc-selenide (ZnSe) window is used as a substrate for a 20–30 nm thick film. On top of the structureless absorption due to ZnSe (<340 ppm), one of the well-known fundamental IR absorption lines of is measured with monolayer sensitivity.
110(1999); http://dx.doi.org/10.1063/1.477998View Description Hide Description
In this paper, we study the liquid–vapor transition of a classical fluid with hard sphere repulsion and short range attraction at criticality in the high dimension limit. We are motivated by physical arguments that relate the presence of percolating clusters to the critical point of the liquid–vapor transition. The volume fraction at the percolation threshold is also expected to decrease for increasing dimension. Together, these imply that the critical density may decrease with dimensionality and for sufficiently high dimension, the truncated low order virial expansion should suffice in describing the critical point. We evaluate analytically the exact second and third virial coefficients for high dimension and explicitly show the modifications of the hard sphere coefficients by the attractive part of the potentials. Then, the truncated virial expansion at criticality is used to demonstrate that the critical volume fraction indeed decreases with dimensionality. This will allow us to propose that the truncated virial expansion provides an accurate description of fluid criticality in the high dimension limit.
110(1999); http://dx.doi.org/10.1063/1.477999View Description Hide Description
An angle resolved photoemission work for a benzene-adsorbed Cu(111) surface with a photon energy of 5.45 eV has revealed that an adsorption-induced state due to hybridization of benzene and copper shows dispersion with electron momentum along the surface. The dispersion is reproduced well by a parabola with an effective electron mass ratio This suggests that the bonding state extends many copper lattice spacings from the adsorbed molecule. The bonding orbital is thought to be the origin of long range interactions of molecules on a metal surface.