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Showing papers by "John B. Pendry published in 1976"


Journal ArticleDOI
TL;DR: In this paper, the separate ingredients known to be important in photoemission: band structure, surface effects, matrix elements and scattering of the outgoing wave are drawn together within a single "dynamic" formalism with the objective of finding a rapid method of calculation.

400 citations


Journal ArticleDOI
TL;DR: In this article, the Fourier transform of an EXAFS spectrum carefully doctored to avoid data truncation effects is used to monitor the contribution of each scattering path to the spectrum, and single-scattering paths can be calculated to good accuracy, and fitted to give shell radii, mean square correlated vibrational amplitudes for each shell, and to identify the type and number of atoms in each shell.

50 citations


Journal ArticleDOI
TL;DR: In this paper, an explanation for the large negative heat of solution of helium in metals, in terms of the strong repulsive helium pseudopotential interacting with the metal conduction electrons, was proposed.
Abstract: We propose an explanation for the large negative heat of solution of helium in metals, in terms of the strong repulsive helium pseudopotential interacting with the metal conduction electrons. Calculations for helium in aluminium and magnesium show that this mechanism indeed generates the expected negative heats. We expect the helium atoms always to seek out the site of lowest charge density.

34 citations


Journal ArticleDOI
TL;DR: In this article, a Van der Waals interaction and strong coupling to quantized surface-tension waves were used to suppress all other influences on the reflectivity of liquid surfaces to externally incident /sup 4/He atoms.
Abstract: We explain recent results on the reflectivity of liquid /sup 4/He surfaces to externally incident /sup 4/He atoms in terms of a Van der Waals interaction and strong coupling to quantized surface-tension waves which suppresses all other influences on the reflectivity The model gives numerical agreement with experiment and it is found that a proper treatment of density variation at the liquid /sup 4/He surface is essential (AIP)

27 citations


Journal ArticleDOI
TL;DR: Sodium and sulphur on an (001) nickel surface were investigated in this article in the c(2*2)S-c(2 *2)Na, c( 2 * 2 )S-p(2 2 )Na, and p( 2*2 )S -p 2 *2 )Na configurations.
Abstract: Sodium and sulphur on an (001) nickel surface are investigated in the c(2*2)S-c(2*2)Na, c(2*2)S-p(2*2)Na, and p(2*2)S-p(2*2)Na configurations. Sulphur always sits in hollows 1.3 AA from the nickel surface. Sodium always lies above hollows in the nickel substrate 2.5 AA from the substrate, but prefers to maximize the number of sulphur nearest neighbours.

21 citations


Journal ArticleDOI
TL;DR: In this article, various models for the construction of ion-core potentials presently used in LEED intensity spectra calculations are tested for nickel and it is shown that self-consistent iterations of these ioncore potential models do not produce significant improvement over the simple linear superposition scheme in building LEED potentials.

20 citations


Journal ArticleDOI
TL;DR: In this article, the chain method of calculating RHEED intensities is investigated and convergence of various expansions is tested and the range of feasibility for the full multiple scattering treatment is found to be up to 5 keV incident energy at present.
Abstract: The so-called 'chain method' of calculating RHEED intensities is investigated. Convergence of the various expansions is tested and the range of feasibility for the full multiple scattering treatment is found to be up to 5 keV incident energy at present. This covers the energy range proposed for determination of atomic coordinates at surfaces, and the sensitivity of RHEED to atomic positions is investigated.

17 citations


Journal ArticleDOI
TL;DR: In this paper, the authors explain the anomalous result in terms of Van der Waals forces and coupling to the ripplons which swamps all other processes, and confirm that the surface of liquid 4He is diffuse on a scale of 5 AA.
Abstract: The experimental elastic reflectivity of 4He atoms from liquid 4He surfaces behaves as if the 4He atoms are reflected from a very smooth elastic potential. The authors explain this anomalous result in terms of Van der Waals forces and coupling to the ripplons which swamps all other processes. Interpretation of the experiments confirms that the surface of liquid 4He is diffuse on a scale of 5 AA.

7 citations


Journal ArticleDOI
TL;DR: In this article, the surface state density on the (001) surface (assumed to consist of nickel atoms) of the antiferromagnetic phase of hexagonal nickel sulphide was calculated.

2 citations