Showing papers by "John B. Pendry published in 1980"
TL;DR: In this paper, the double-R reliability factor (RR) was introduced, where R*RR is the variance of R. This enables quantitative statements to be made about the significance of minima in R.
Abstract: A new R-factor is defined which is insensitive to intensity discrepancies between theory and experiment but retains a simple functional form. An error analysis of R introduces another new quantity, the 'double-R' reliability factor, RR, where R*RR is the variance of R. This enables quantitative statements to be made about the significance of minima in R.
661 citations
TL;DR: In this paper, the spin-polarized electron sources were used to study magnetism with the inverse photo-emission technique, where the energy and momentum in the transition gives information about unfilled bands, of the same kind that angle-resolved photoemission gives for the filled bands.
Abstract: Electrons accelerated by the potential inside a surface emit photons with a probability related by time reversal to excitation of an electron in photoemission. Conservation of energy and momentum in the transition gives information about unfilled bands, of the same kind that angle-resolved photoemission gives for the filled bands. Particularly interesting is the possibility of using the new spin-polarized electron sources to study magnetism with the inverse photoemission technique.
126 citations
TL;DR: In this paper, more powerful theoretical analysis provided an accurate determination of geometry for the c(2 × 2)CO/Cu(001) and Ni(001), and the new CO bond length is 1.15 A.
Abstract: New experiments and more powerful theoretical analysis provide an accurate determination of geometry for the c(2 × 2)CO/Cu(001) and Ni(001) structures. The new CO bond length is 1.15 A and the molecule is essentially vertical in both cases, resolving an earlier discrepancy with photoemission data. New theoretical methods for handling molecules at surfaces are described which can be extended to molecules much larger than CO. Some discussion of thermal vibrations is made.
63 citations
TL;DR: In this article, a formal discussion of this surface state is followed by a model for emission of e+ and Ps from the surface which is compatible with the experimental data, including the temperature dependence.
Abstract: Recent experiments (Mills, 1978-79) on the emission of positrons from surfaces are shown to imply that positrons are trapped in a surface state prior to emission. A formal discussion of this surface state is followed by a model for emission of e+ and Ps from the surface which is compatible with the experimental data, including the temperature dependence. Some further experimental tests of the model are suggested.
20 citations
TL;DR: In this paper, the azimuthal anisotropies in deep core level X-ray photoemission from atoms adsorbed on single-crystal surfaces have been observed and were found to be well described by a single-scattering model, thereby providing a new method for determining surface atomic geometries.
20 citations
TL;DR: In this paper, the authors developed a theory of the electronic structure of liquids in terms of the reflectivity of an effective medium in which the atoms are embedded, which is essential to a good theory: the finite size of the potential, details of the pair correlation function and the inclusion of three-body and higher correlations.
Abstract: Theories of the electronic structure of liquids are developed in terms of the reflectivity of an effective medium in which the atoms are embedded. The structure of this medium is essential to a good theory: the finite size of the potential, the details of the pair correlation function and the inclusion of three-body and higher correlations. Finally a calculation is presented which reproduces the correct bandwidth for liquid copper.
7 citations
2 citations
TL;DR: In this article, the authors show that simple metals are perhaps the best understood of all solids and the reason is that the electron wavefunctions are plane-wave-like to a first approximation and deviations can be treated by perturbation theory.
Abstract: When the atoms of simple metals condense from the gas phase to give a solid, the valence electron wavefunctions are strongly modified by their overlap. At first sight this strong overlap might be expected to produce a complex situation, difficult to treat quantitatively. Yet the simple metals are perhaps the best understood of all solids and the reason is that the electron wavefunctions are plane-wave-like to a first approximation and deviations can be treated by perturbation theory.
2 citations