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Interaction of CN compounds with clean and oxygen dosed Cu(110) and Cu(111) surfaces studied by auger, electron energy loss and thermal desorption spectroscopy
Abstracts
must be utilized in the preparation and characterization of well defined chemical, electronic and geometric submicron structures. As dimensions of electronic devices shrink to the submicron regions, the physics for treating the motion or other charge carriers becomes different and surface as well as interface effects become predominant. As a result, technological improvements require an atomistic understanding of electronic structures of semiconductor/metal and semiconductor/semiconductor interfaces. In this context, systematic studies of initial steps of interface formation are of great importance if performed under ultrahigh vacuum conditions. Independent of their technological importance, these studies will be shown to provide an atomistic understanding of the formation of ohmic contacts and Schottky harriers, of electronic processes in semiconductor gas-sensors and of charge transfer reactions during heterogeneous catalysis on semiconductor surfaces. V6 Application of ion beams for ~
preparation of thin films
C Websmantel, Sektion Physik/Elektronische Bauelemente, Technische Hochschule Kari-Marx-Stadt, DDR 9010, PSF 964 The effects of ion-solid-interaction, i.e. atomic displacements sputtering and thermal spike phenomena, can be used to prepare special film structures including highly metastable layers. The capabilities of ion beam techniques for thin film preparation and surface modification are outlined in conjunction with experimental configurations. Recent results are discussed in the context of the following topics: (1) Ion beam sputter deposition of crystalline and amorphous silicon films and the formation of graphoepitaxial films; (2) the preparation of hard i-carbon layers by ion beam sputter techniques and by the deposition of molecular ions obtained from hydrocarbons; (3) the growth of composite layers, as Ag/SiO2 cermet films or Cr/C structures, by ion beam techniques. In an outlook, relations between ion beam and plasma processes and combinations between ion beam etching, implantation and deposition steps are discussed. V7 Interaction of CN compounds with clean and oxygen dosed Cu(ll0) and Cu(lll) surfaces studied by auger, electron energy loss and thermal d~sorption spectroscopy F Solymosi, Reaction Kinetics Research Group, The University, PO Box 105, H-6701 Szeged, Hungary The adsorption and surface reaction of HNCO, HCN and C2H: on clean and oxygen covered Cu(1000) and Cu(lll) have been investigated. The primary aim of this study is to obtain a deeper insight into the formation, reaction and decomposition of NCO species, which is an important surface intermediate of NO + C O catalytic reaction. For this purpose LEED, Auger electron, electron energy loss and thermal desorption spectroscopy were applied. In contrast to the Pt surfaces neither HNCO nor HCN adsorb on clean Cu surfaces at 300 K. The presence of adsorbed oxygen, however, greatly promoted the interaction, and caused the dissociative adsorption of both compounds. It appeared that NCO is a stable species on Cu surfaces up to 400 K, but above this 130
temperature it reacted with chemisorbed oxygen. On the other hand, electron energy loss measurements indicated that surface CN groups interact with chemisorbed oxygen at lower temperatures resulting in the formation of NCO species. The possible mechanism of the surface processes and their relevance to the NO + CO catalytic reaction are discussed in detail.
V9 The importance of technology assessment in the energy field P J Jansen, lnstitut far Energiewirtschaft Technische Universit;~t Wien, Wiedner Hauptstra[~e 7-9, A-1040 Wien The acceptance of new technologies gets more and more difficult. Apparently there is a feeling in part of the society that benefits from new technologies are dominated by their costs. 'Costs' hereby span the economic as well as the sociological and environmental burdens and risks. It is important, therefore, to rationalize that cost/benefit analysis in the broader sense, that is to improve and apply technology assessment methodology in order to improve the cost/benefit ratio, to concentrate on activities of generally accepted importance and to facilitate acceptance by offering a deeper insight in the complex interactions of technology and society. VI0 Saving energy and energy collection by thin film technology H Schr/ider and E Hussmaan, Glaswerke Schott, D-500 Mainz, BRD After a brief review of the different techniques of coating substrates with thin films (vacuum techniques, spray and dip coating, chemical vapour deposition) the fields of application relative to saving energy and energy collection are discussed: (1) Sun shielding window systems (2) Heat insulating window systems (3) Photothermal solar energy collection: selective transparent cover panes, mirrors, AR (antirefiecting) coatings, selective absorber coatings (4) Photovoltaic solar energy collection: concentrating mirrors, enhancement of absorption by Ar coatings, dichronic mirrors for photovoltaic cells with different spectral response. The physical basis of the applications is explained; approved systems, their optical properties, advantages and benefits are characterized. As the properties of window systems can be calculated from the properties of the single panes, such systems can be designed and optimized by simulating calculations. PI Connection of the gas dynamic and kinetic diffusion pumping theories G Toth, Physical Institute of the Technical University, H- 1111. Budafoki ut 8. Budapest, Hungary In diffusion pumping theories the pumping effect is usually treated in two ways, either phenomenologically by gas dynamics or by kinetic mean-free-path methods, it is shown that the two kinds of
must be utilized in the preparation and characterization of well defined chemical, electronic and geometric submicron structures. As dimensions of electronic devices shrink to the submicron regions, the physics for treating the motion or other charge carriers becomes different and surface as well as interface effects become predominant. As a result, technological improvements require an atomistic understanding of electronic structures of semiconductor/metal and semiconductor/semiconductor interfaces. In this context, systematic studies of initial steps of interface formation are of great importance if performed under ultrahigh vacuum conditions. Independent of their technological importance, these studies will be shown to provide an atomistic understanding of the formation of ohmic contacts and Schottky harriers, of electronic processes in semiconductor gas-sensors and of charge transfer reactions during heterogeneous catalysis on semiconductor surfaces. V6 Application of ion beams for ~
preparation of thin films
C Websmantel, Sektion Physik/Elektronische Bauelemente, Technische Hochschule Kari-Marx-Stadt, DDR 9010, PSF 964 The effects of ion-solid-interaction, i.e. atomic displacements sputtering and thermal spike phenomena, can be used to prepare special film structures including highly metastable layers. The capabilities of ion beam techniques for thin film preparation and surface modification are outlined in conjunction with experimental configurations. Recent results are discussed in the context of the following topics: (1) Ion beam sputter deposition of crystalline and amorphous silicon films and the formation of graphoepitaxial films; (2) the preparation of hard i-carbon layers by ion beam sputter techniques and by the deposition of molecular ions obtained from hydrocarbons; (3) the growth of composite layers, as Ag/SiO2 cermet films or Cr/C structures, by ion beam techniques. In an outlook, relations between ion beam and plasma processes and combinations between ion beam etching, implantation and deposition steps are discussed. V7 Interaction of CN compounds with clean and oxygen dosed Cu(ll0) and Cu(lll) surfaces studied by auger, electron energy loss and thermal d~sorption spectroscopy F Solymosi, Reaction Kinetics Research Group, The University, PO Box 105, H-6701 Szeged, Hungary The adsorption and surface reaction of HNCO, HCN and C2H: on clean and oxygen covered Cu(1000) and Cu(lll) have been investigated. The primary aim of this study is to obtain a deeper insight into the formation, reaction and decomposition of NCO species, which is an important surface intermediate of NO + C O catalytic reaction. For this purpose LEED, Auger electron, electron energy loss and thermal desorption spectroscopy were applied. In contrast to the Pt surfaces neither HNCO nor HCN adsorb on clean Cu surfaces at 300 K. The presence of adsorbed oxygen, however, greatly promoted the interaction, and caused the dissociative adsorption of both compounds. It appeared that NCO is a stable species on Cu surfaces up to 400 K, but above this 130
temperature it reacted with chemisorbed oxygen. On the other hand, electron energy loss measurements indicated that surface CN groups interact with chemisorbed oxygen at lower temperatures resulting in the formation of NCO species. The possible mechanism of the surface processes and their relevance to the NO + CO catalytic reaction are discussed in detail.
V9 The importance of technology assessment in the energy field P J Jansen, lnstitut far Energiewirtschaft Technische Universit;~t Wien, Wiedner Hauptstra[~e 7-9, A-1040 Wien The acceptance of new technologies gets more and more difficult. Apparently there is a feeling in part of the society that benefits from new technologies are dominated by their costs. 'Costs' hereby span the economic as well as the sociological and environmental burdens and risks. It is important, therefore, to rationalize that cost/benefit analysis in the broader sense, that is to improve and apply technology assessment methodology in order to improve the cost/benefit ratio, to concentrate on activities of generally accepted importance and to facilitate acceptance by offering a deeper insight in the complex interactions of technology and society. VI0 Saving energy and energy collection by thin film technology H Schr/ider and E Hussmaan, Glaswerke Schott, D-500 Mainz, BRD After a brief review of the different techniques of coating substrates with thin films (vacuum techniques, spray and dip coating, chemical vapour deposition) the fields of application relative to saving energy and energy collection are discussed: (1) Sun shielding window systems (2) Heat insulating window systems (3) Photothermal solar energy collection: selective transparent cover panes, mirrors, AR (antirefiecting) coatings, selective absorber coatings (4) Photovoltaic solar energy collection: concentrating mirrors, enhancement of absorption by Ar coatings, dichronic mirrors for photovoltaic cells with different spectral response. The physical basis of the applications is explained; approved systems, their optical properties, advantages and benefits are characterized. As the properties of window systems can be calculated from the properties of the single panes, such systems can be designed and optimized by simulating calculations. PI Connection of the gas dynamic and kinetic diffusion pumping theories G Toth, Physical Institute of the Technical University, H- 1111. Budafoki ut 8. Budapest, Hungary In diffusion pumping theories the pumping effect is usually treated in two ways, either phenomenologically by gas dynamics or by kinetic mean-free-path methods, it is shown that the two kinds of