Fromm Kinetics of Metal-Gas Interactions at Low Temperatures

Hydriding, Oxidation, Poisoning
Erscheinungsjahr 2012
ISBN: 978-3-642-60311-2
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 36, 206 Seiten, eBook

Reihe: Springer Series in Surface Sciences

Kinetics of Metal-Gas Interactions at Low Temperatures is devoted to the formation of a natural oxide film. This few nm thick surface layer is produced instantaneously if oxygen or water vapor is present in the gas atmosphere. It is responsible for the corrosion behavior, for wear and friction of metallic materials, as well as for hydrogen embrittlement or poisoning of catalytic surface reactions. Oxidation impedes experiments in surface sciences and production processes in modern thin-film technology. It can reliably be avoided only if expensive ultra-high vacuum techniques are applied. This monograph presents an introduction to the subject in a tutorial style. It demonstrates how complex metal-gas interactions can be analyzed by standard procedures of chemical kinetics.

Zielgruppe

Research

Autoren/Hrsg.

Fromm, Eckehard

Inhaltsverzeichnis

1 Introduction.- 2 Principles of Reaction Kinetics.- 2.1 Equilibria of Chemical Reactions.- 2.2 Structure of Reaction Models.- 2.3 Characteristics of Reaction Partial Steps.- 3 Experimental Techniques.- 3.1 Initial State of Metal Surfaces and UHV Experiments.- 3.2 Volumetric and Manometric Methods.- 3.3 Quartz Crystal Microbalance.- 3.4 Ellipsometry.- 3.5 Energetic Ion Scattering.- 3.6 X-Ray Reflectivity.- 3.7 Surface-Analytical Methods.- 4 Hydrogen Reactions.- 4.1 Experimental Results.- 4.2 Hydrogen Solution in Metals.- 4.3 Hydride Formation.- 4.4 Computer Simulation of Advanced Models.- 5 Low-Temperature Oxidation.- 5.1 Experimental Results.- 5.2 Rate Laws Proposed in the Literature.- 5.3 Partial Steps of the Oxidation Reaction.- 5.4 Relations and Constants Used in Model Calculations.- 5.5 Example of a Model Considering Space Charges.- 5.6 Models Neglecting Space Charges.- 5.7 Detailed Presentation of a Model with Metal Interstitials as Mobile Defects.- 5.8 Results of Model Calculations, Parameter Variations.- 5.9 Effects of the Defect Structure of the Oxide.- 5.10 Simulation of Experiments with the Volumetric Method.- 5.11 Reaction Mechanisms of Low-Temperature Oxidation.- 6 Poisoning of Hydrogen Reactions.- 6.1 Experimental Results.- 6.2 Stability of Oxide Layers at Elevated Temperatures.- 6.3 Surface Layer of Constant Thickness.- 6.4 Contamination Layers Growing During Exposure.- Appendices.- A Chemical Potentials and Standard States.- A.1 Chemical Potentials.- A.1.1 Definitions.- A.2 Standard States and Standard Reactions.- A.2.1 Elements.- A.2.3 Physisorption.- A.2.4 Molecular Chemisorption.- A.2.5 Atomic Chemisorption.- A.2.6 Metal Interstitials.- A.2.7 Metal Vacancy.- A.2.8 Oxygen Interstitials.- A.2.9 Oxygen Vacancy.- A.2.10Other Compounds.- B Equilibria of Charged Species.- B.1 Poisson Equation.- B.2 Dipole Layers.- B.3 Space Charges.- B.3.3 Conclusions.- B.4 Mott Potential.- B.4.1 Oxygen Molecules as Acceptors.- B.4.2 Oxygen Atoms as Acceptors.- B.4.3 Pressure Independent Acceptor Sites.- B.4.4 Conditions for the Existence of a Mott Equilibrium Potential.- B.5 Equilibria in Oxide Layers.- C Electronic Currents.- C.1 Tunneling.- C.2 Hopping Mechanism.- C.3 Semiconduction.- D Ionic Currents.- D.1 Basic Equations.- D.1.1 Zero Concentration Gradient.- D.1.2 Zero Field Current.- D.1.3 High Field Transport Equation.- D.1.4 Steady State Current in a Homogeneous Field.- D.2 Space Charge Effects.- D.3 Coupled Currents.- E Units, Material Constants.- Symbols.- References.