Surface and Defect Properties of Solids, Volume 6 a review of the recent literature published up to mid-1976

412 Pages·1977·22.612 MB·English

by  Meirion Wyn Roberts, Chemical Society (Great Britain)

A Specialist Periodical Report
Surface and Defect Properties
of Solids
Volume 6
A Review of the Recent Literature published
up to mid-I976
Senior Reporters
M. W. Roberts, Department of Chemistry, University of Bradford
J. M. Thomas, Edward Davies Chemical Laboratories,
Universify College of Wales, Aberystwyth
Reporters
3. Corish, University College Belfield, Dublin, Eire
R. M. Hooper, University of Exefer
J. L. Hutchison, University College of Wales, Aberystwyth
P. W. M. Jacobs, University of Western Ontario, Canada
D. A. Jefferson, University College of Wales, Aberystwyfh
G. G. Kleiman, Universidad Nacional Aufonoma de Mexico, Mexico
Z. Knor, Czechoslovak Academy of Sciences, Prague, Czechoslovakia
U. Landman, University of Rochester, New York, U,S.A.
D. R. Lloyd, University of Birmingham
C. M. Quinn, University of Birmingham
S. Radhakrish na, lndian lnstifute of Technology, Madras, India
N. V. Richardson, University Df Birmingham
3. N. S herwood, University of Strathclyde, Glasgow
6. K. Tanner, University of Durham
M. J. Tricker, Heriot- WaffU niversity, Edinburgh
The Chemical Society
Burlington House, London WIV OBN
IS8N: 0 85186 300 0
I SS N : 0305-3873
Library of Congress Catalog Card No. 72-78528
Copyright 0 1977
The Chemical Society
All Rights Reserved. No part of this book may be reproduced ortransmitted
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written permission from The Chemical Society.
Printed in Great Britain by
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Preface
For the first time in this series we have considered physisorption, one of the pillars of
contemporary surface chemistry. Landman and Kleirnan have adopted a detailed
microscopic approach covering both theoretical and experimental aspects of
physisorption and drawing widely7fromd iverse areas of science to provide a thorough
analysis of the current state of knowledge. An interesting contrast is evident in the
articles of Knor on the one hand and Lloyd, Quinn, and Richardson on the other,
Knor has chosen to consider in an essentially phenomenological fashion the inter-
play between theory and experiment with relation to the surface chemistry of metals.
He poses problems for the theoretician and asks questions of the experimentalist.
Lloyd, Quinn, and Richardson consider the particular advantage of one recent
experimental development, namely angle-resolved ultraviolet photoelectron spectro-
scopy, in relation to theoretical aspcds of mctal surfacesper se and also adsorption
on these surfaces, The general area of photoemission from metal surfaces has been
considered in previous vdurnes (Roberts, Brundle, Spicer et al., Mason et a!.) but
this is the first time we have discussed in detail the advantages that accrue from
angular studies. A new departure in this volume is a review of the application of
conversion electron Mossbauer spectroscopy to surface studies, by Tricker, who
describes the experimental approach, discusses various aqpects of the sensitivity
of the technique, and outlines some successful applications.
Tanner’s contribution also represents a new departure for this series. His succinct
account, ihstrated with examples from disparate fields, of how crystal perfection
may be assessed by X-ray topographic methods is particularly timeiy, since it is very
likely that considerable reliance will in future be placed onnon-destructive topographic
methods with the continued advances in X-ray optics and with the increasing
availability of synchrotron radiation. The comprehensive chapter by Corish, Jacobs,
and Radhakrishna returns to the topic of point defects in ionic crystals which was the
subject of a major review (by Corish and Jacobs) in Volume 2. Ionic solids continue
to elicit the interest of a wide spectrum of researchers, from the computational
physicists on the one hand to those engaged in technological developments asso-
ciated with fuel cells, solar energy converters, electrocatalysts, and the like on the
other. It is appropriate, therefore, that as well as dealing with intrinsic and impurity
(ionic and molecular) defect parameters in ionic cryslals, fast ion conduction is also
discussed.
The two remaining chapters differ markedly from one another. Sherwood’s
summarizing cuntribution focuses attention upon highly plastic molecular crystals
where interesting advances have been made, many by Sherwood himself, in the past
three years. In this context the dislocation is of paramount importance. In the final
chapter Hutchison, Jefferson, and Thomas survey the current scene in the solid-state
structural chemistry of a range of minerals. Enormous progress, chiefly through the
agency of high-resolution microscopes (the principles of which were reviewed by
Anderson and Tilley in Volume 31, has been made in this area within the past few
years, In this particular context, the importance and ubiquity of planar faults,
iv Preface
Wadsley defects, recurrent twinning, coherent intergrowths (all of which have been
touched upon in previous volumes of these reports) are strikingly apparent,
Necessarily, several cIasses of minerals, notably the feldspars, have had to be omitted
in this survey. We plan to repair this omission in a future report.
M. W. Roberts
April 1977 J. M. Thomas
Cont eats
Chapter 1 Microscbpic Approaches to Physisorption:
Theoretical and Experimental Aspects 1
By U. Landman and G. G,K leirnan
1 Introduction 1
2 Theoretical Approaches for the Study of Physisorption 2
Introduction 2
van der Waals Forces and Physical Adsorption 5
Semi-empirical Calculations 19
Fundamental Calculations of Physisorption Binding Energies 21
3 Microscopic Experimental Methods for the Study of
Phy sisorption 33
Introduction 33
General Introductory Remarks 33
On the Use of UPS in Characterization of the
Phy sisorpt ion State 34
Experimental Techniques for the Study of Atomic
Arrangement in Physisorption Systems 39
LEED : Background Remarks 40
LEED Studies of Physisorption Systems 43
Neutron Scattering : Background Remarks 56
The Adsorption of NP and 36Aro n Graphite 60
The Study of Thermal Vibrations using LEED 62
Low Energy Molecular (Atomic) Beam Scattering (LEMS) 66
Experimental Observations. Scattering Regimes 68
Experimental Observations. Diffraction of Rare
Gases from Metals 70
Experimental Observations. Selective Adsorption 74
On Interaction Potentials used in Theoretical
Analysis of LEMS 77
Experimental Techniques for the Study of the Electronic
Structure of Physisorbed Systems 82
Ul t ravidet Phot aemis si on Spectroscopy (W PS) 82
X-Ray Photoemission Spectroscopy (XPS) 85
Electron Energy Loss spectroscopy (EELS) 90
Field Emission Techniques 90'
Field Emission and the Probe-hole Techniques 92
Field Emission. Theoretical Considerations 94
Vi Cuntents
Measurement of Adsorption Isotherms via Electron
Spectroscopy 97
Auger Electrun Emission in Adsorption Isotherm Studies 100
4 Conclusion 103
Chapter 2 57-Iron Conversion Electron Mossbauer Spectroscopy 106
By M.J . Tricker
1 Introduction 106
2 Principles of the Mossbauer Effect 106
3 Interaction of the Nucleus with its Environment
Chemical Isomer Shift 108
Quadrupole Interaction 109
Magnetic Interaction 109
Spectral Areas 110
4 Surface Studies 111
5 Internal Conversion 113
6 Theory of the Attenuation of 57FeC onversion Electrons 115
7 57FeC EMS Experimental Considerations 116
8 Probing Depth and Sensitivity 120
9 Applications 127
Corrosion and Oxidation Studies 127
Surface Phase Analyses of Steels 130
Surface Stress Measurements 131
Ion Implantation Studies 131
Applications in Geochemistry 134
10 Depth Selective 57FeC EMS 137
11 Conclusions 138
Chapter 3 The Interplay of Theory and Experiment in the Field
of Surface Phenomena on Metals 139
By 2,K nor
1 Introduction 139
2 Bare Metal Surfaces 139
Theoretical Models of Metal Surfaces 139
Comparison of Theoretical and Experimental Results 151
Contents vii
3 Chemisorption of Gas Molecules on Transition Metal Surfaces 160
Model Representation of the Gas-Metal System 160
CFSO-BEBO Approach 162
The Localized Free EIectron InterpIay Model 163
The Comparison of Theoretical and Experimental Results 167
4 Conclusion 178
Chapter 4 Angle-resolved Ultraviolet Photoelectron Spectroscopy
of Clean Surfaces and Surfaces with Adsorbed Layers 179
By D. R. Lloyd, C. Ad. Quinn, and N. V. Richardson
1 Introduction 1 79
2 Photoemission from Clean Surfaces 180
Theory 180
Comparisons with Angle-resolved Spectra 189
3 Angle-resolved Spectra of AdsorM Spccies 205
Thmry 205
Comparison with Experiment 21 1
Chapter 5 Point Defects in ionic Crystals 218
By J. Corish, P. W. M. Jacobs, and S. Radhakrishna
1 Introduction 218
2 Intrinsic Defect Parameters 21 9
Self-diffusion 219
Ionic Conductivity 221
3 Impurity Defect Parameters 227
Diffusion of Impurities 227
Impurity-Vacancy Complexes 228
4 Theoretical Calculation of the Properties of Point Defects 234
Defect Energies : Methods 234
Defect Energies : Results 235
Defect Interactions 243
Rare Gas Diffusion in Ionic Crystals 245
Defect Entropies 245
5 Fast Ion Conduction 246
Ag+ and Cu+ as Fast Ion Conductors 247
Fast Conduction by Alkali Ions 249
Anionic Fast Conduction 25 1
...
Vlll Contenls
6 Paraelectric Impurities 252
Static and Dynamic Behaviour of PEC 252
Devonshire Model 253
Multi-well Potential Tunnelling Model 253
Experimental Techniques and Data 254
Electro-optical Technique 254
Electrocaloric Method 255
Specific Heat Measurements 255
Paraelectric Resonance 25 5
The Kerr Effect Method 255
7 Molecular Impurities 25 8
Diatomic Molecular lons 258
Triatomic Molecular Tons 262
Planar Molecular Ions 262
Molecular lons of Tetrahedral Symmetry 263
Complex Molecular Ions 266
8 Impurity Ions with the S2 Configuration 269
Emission 276
Chapter 6 Assessment of Crystal Perfection by
X-Ray Topography 280
By B. K. Tanner
1 Introduction 280
2 Techniques of X-Ray Topography 28 1
Laboratory X- Radiation Techniques 28 1
The Berg-Barrett Topography 28 1
The Lang Technique 282
The Double Crystal Method 284
X-Kay Topography using Synchrotron Radiatiun 288
Direct Viewing of A'-Ray Topographs 289
3 Contrast on X-Ray Topographs 290
Perfect Crystal Phenomena - Pendelliisung 290
Contrast of Dislocations 294
Contrast of Stacking Faults 298
Contrast of Twins and Sub-grains 300-
4 Applications to Crystal Defect Studies 300
Crystal Growth 300
Metallurgy and Plastic Deformation 303
Mineralogy 304
('ontrol of Electronic Devices 305
Oxidation Studies 307