High resolution spot profile analysis low energy electron diffraction (SPA-LEED) and variable temperature scanning tunneling microscopy (STM) have been used to observe the growth of Pb on the Pb/Si(111)-??3�?3 phase, which is driven by quantum size effects (QSE). A change in the rotation of the Pb grown islands with respect to the Si substrate has been observed with ...

We present an experimental approach for the recording of two-dimensional reciprocal space maps using spot profile analyzing low energy electron diffraction (SPA-LEED). A specialized alignment procedure eliminates the shifting of LEED patterns on the screen which is commonly observed upon variation of the electron energy. After the alignment, a set of one-dimensional sections ...

Step-Induced Magnetic Anisotropy on Fe/W(001) vicinal surfaces. In previous publications, we have reported the presence of step-induced magnetic anisotropy on a thin film Fe/W[100]surface. (J.Chen, J.L. Erskine, PRL 68,1212 (1992)) We extend that study to include a variably stepped W substrate which offers a continuum of step widths 5-60 Angstroms wide, verified with Spot Profile Analysis-Low ...

Cu(110) and the vicinal Cu(19 19 1) surfaces were characterized by recording maps of the reciprocal space by means of spot profile analysis low-energy electron diffraction (SPA-LEED). For both surfaces, kinematic simulations were performed to get insight into the main features of the experimental data. Furthermore, it is shown that chemisorption of oxygen and subsequent ...

We have investigated the structure and morphology of the tenfold surface of decagonal Al71.8Ni14.8Co13.4 by highly surface sensitive He atom scattering (HAS), high resolution low energy electron diffraction(SPA-LEED), and low temperature scanning tunneling microscopy (STM). The SPA-LEED patterns reveal more than 500 individual diffraction spots in the k -vector range of ...

Ultrathin crystalline silica layers grown on a Mo(112) substrate have been shown to be a useful silica model oxide support in surface science model catalyst studies. As the oxide support material plays an important role in the catalytic process, a multitechnique surface science study is presented to characterize the morphological and electronic properties of the heteroepitaxial system ...

An important goal in present day surface science is to grow uniform sized self-assembled nanostructures. One system which has displayed a number of interesting surface structures is Pb grown on a Si(111) substrate. The first part of the thesis discusses the "Devil's Staircase" (DS) of linear phases studied with Scanning Tunneling Microscopy (STM) and Spot-Profile Analysis Low Energy Electron ...

This work examines the red luminescence of benitoite studiedby laser-induced time-resolved luminescence spectroscopy. This methodallows the differentiation between luminescence centers of similaremission wavelengths, but different decay times. We have also examinedthe luminescence intensity and decay time as a function of temperature.We found that the red emission of benitoite ...

The scanning tunneling microscope has been used to observe sites selection of diene molecules on Si(111) 7�7 as a function of their chain length. The molecules 1,6-heptadiene and 1,7-octadiene can chemisorb on either of three geometries on the surface. The different relative affinity of the molecules to these sites is explained by matching between the molecules length and the surface sites. For ...

Surface Magneto Optic Kerr Effect (SMOKE) measurements of ultrathin layers of Fe on graded-step-density W(001) are used to test essential predictions of a hysteresis loop phase diagram model reported by Zangwill et al. [1]. The one-dimensional micromagetic model produces a rich variety of hysteresis loop shapes as well as predictions of switching field strengths that depend on two parameters: ? = ...

Thin films of the model molecule perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) were vacuum deposited on epitaxial NaCl films on Ag(100) and investigated by spot-profile-analysis low-energy electron diffraction (SPA-LEED). At growth temperatures between 193 K and room temperature (RT), the first layer (monolayer) exhibits a commensurate (32�32)R45� ...

This thesis was developed to address the following questions for the Pb/Si(111) system: (1) Is it possible to control the nano-structure growth by changing the initial substrate; (2) is the nucleation theory applicable to the case of the 7-step growth mode; and (3) what phase or phases could be formed between coverage 6/5 ML and 4/3 ML? The first question was answered in chapter 2, different ...

Low Energy Electron Diffraction (LEED) has been used to determine the structure of ultrathin films (1 and 2 monolayers) of Fe on W(001), by conducting LEED Intensity versus Voltage (LEED IV) analysis and comparison with experimental data. Spot Profile LEED (SPA-LEED) has been used to determine the changes in the long-range order induced by oxygen chemisorption on ultrathin ...

The influence of the metal cluster size and the identity of the support on the reactivity of gold based catalysts have been studied in the CO oxidation reaction. To overcome the structural complexity of the supported catalysts, gold nanoparticles synthesized from colloidal chemistry with precisely controlled size have been used. Those particles were supported over SiO{sub 2} and TiO{sub 2} and ...

The main aim of this investigation was to delineate the distribution of the 5-HT₇ receptor in human brain. Autoradiographic studies in guinea-pig and rat brain were also carried out in order to revisit and compare the anatomical distribution of 5-HT₇ receptors in different mammalian species.Binding studies were performed in rat frontal cortex membranes ...