Determination of domain distribution by analysis of LEED beam profiles

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Diffuse LEED intensities of disordered crystal surfaces : II. Multiple scattering on disordered overlayers

The diffraction of low energy electrons from disordered overlayers adsorbed on ordered substrates is treated theoretically by an extension of Beeby's multiple scattering method. A lattice gas model is assumed for the disordered adsorbate layer. Multiple scattering within a certain area around each atom — each atom of the overlayer and within the ordered substrate — is treated self-consistently, the remaining contributions to the total scattering amplitude being averaged. The theory can be used in the limiting cases of random distribution and of long range order within the adsorbate layer

Diffuse LEED intensities of disordered crystal surfaces : I. Correlations between statistics and multiple diffraction

It is shown that the diffraction of slow electrons from disordered crystal surfaces is correlated with the problem of thermodynamical statistics. The correlation functions are completely determined by the self-energies and interaction energies of neighboring complexes. These quantities solve the problem of a-priori probabilities and the cooperative phenomenon of correlation functions of these complexes. If the calculation of a certain set of multiple scattering amplitudes is possible, the remaining problem of determining the diffuse LEED pattern becomes solvable. The calculation of angular beam profiles follows the same lines as already described for the kinematic theory of X-ray diffraction

Diffuse LEED intensities of disordered crystal surfaces : IV. Application of the disorder theory

The principles of the statistical disorder theory are discussed briefly. The theory is applied to a model of the disordered (101)Au surface with the characteristic (1 × 2) supersstructure. A fit procedure is described, by which the experimental angular intensity profiles are used directly to determine the disorder parameters and the interaction energies between the chains of surface atoms

Diffuse LEED intensities of disordered crystal surfaces : III. LEED investigation of the disordered (110) surface of gold

The LEED pattern of clean (101) surfaces of Au show a characteristic (1 × 2) superstructure. The diffuseness of reflections in the reciprocal [010] direction is caused by one-dimensional disorder of chains, strictly ordered into spatial [10 ] direction. There is a transition from this disordered superstructure to the normal (1 × 1) structure at 420 + 15°C. The angular profiles of the and (01) beam are measured at various temperatures and with constant energy and angles of incidence of the primary beam. The beam profiles are deconvoluted approximately with the instrument response function

Structure determination of the reconstructed Au(110) surface

The LEED pattern of the Au(110) surface shows a (1 × 2) and also a (1× 3) superstructure. The (1 × 2) superstructure has been determined by comparison of LEED intensities with model calculations. The missing row model is the most probable model. A minimum of the averaged r-factor, , has been found for 15% contraction of the first layer spacing without atomic displacements in the second layer

Habits and Envy: What Drives the Consumption Behavior of U.S. Households? Evidence from PSID, 1999-2009

In this paper we estimate the relevance of habits versus interpersonal comparisons for the consumption behavior of U.S. households. We exploit information from the recently released consumption expenditure data of the Panel Study of Income Dynamics (PSID) covering the time span from 1999 to 2009. We find that both habits, measured as lagged consumption, and envy motives, measured as reactions of consumption to consumption changes of households that are perceived to be richer, matter substantially. Hence, household consumption is not only determined by habit persistence but also by interpersonal comparisons. Most importantly, our estimations reveal that envy motives might play a much more prominent role for households' consumption choices than habits do

Consumption-savings decisions under upward looking comparisons: Evidence from Germany, 2002-2011

We demonstrate that interpersonal comparisons lead to keeping up with the Joneses-behavior. Using annual household data from the German Socio-Economic Panel, we estimate the causal effect of changes in reference consumption, defined as the consumption level of all households who are perceived to be richer, on household savings and consumption. When controlling for own income, an increase in reference consumption of 100 euros leads to an increase in consumption of 10 to 25 euros. Upper middle class households are most strongly affected. Our findings provide valuable input for macroeconomic models that consider the economic consequences of interdependent preferences