Principles and Applications of Chemical Defects

Cover
Title Page
Copyright Page
Table of Contents
Preface
1 Point defects
1.1 The importance of defects
1.2 Point defects
1.2.1 Point defects in pure elements
1.2.2 Point defects in compounds
1.3 The equilibrium concentration of Schottky defects in crystals
1.4 The equilibrium concentration of Frenkel defects in crystals
1.5 Schottky and Frenkel defects: trends and further considerations
1.6 Case study: the photographic process
1.6.1 Light-sensitive crystals
1.6.2 The mechanism of latent image formation
1.7 Case study: photochromic glasses
1.8 Supplementary reading
Appendix 1.1 The equilibrium concentration of Schottky defects in crystals
Appendix 1.2 The equilibrium concentration of Frenkel defects in crystals
2 Atomic mobility: diffusion
2.1 Introduction
2.2 Self-diffusion and tracer diffusion
2.2.1 The determination of tracer diffusion coefficients
2.2.2 Temperature variation of diffusion coefficients
2.2.3 The effect of impurities
2.2.4 The penetration depth
2.3 Chemical diffusion
2.3.1 Chemical diffusion coefficients
2.3.2 The Matano-Boltzmann relationship
2.4 Chemical diffusion, intrinsic diffusion and self-diffusion
2.4.1 The Kirkendall effect
2.4.2 Intrinsic diffusion coefficients
2.4.3 The relationship between chemical diffusion and self-diffusion coefficients
2.5 Diffusion in ionic crystals
2.5.1 Ambipolar diffusion
2.5.2 Solid solution formation
2.5.3 Spinel formation
2.6 Case study: corrosion and oxidation reactions
2.7 Short-circuit diffusion
2.8 Supplementary reading
3 The atomic theory of diffusion
3.1 Introduction
3.2 Self-diffusion mechanisms
3.2.1 Energy barriers
3.2.2 Atomic migration and diffusion coefficients
3.2.3 Self-diffusion in crystals
3.2.4 The effect of the defect population
3.3 The Arrhenius equation and the effect of temperature
3.4 The relationship between D and diffusion distance
3.5 Correlation effects
3.6 Case history: integrated circuits
3.7 Ionic conductivity
3.7.1 The relationship between ionic conductivity and diffusion coefficient
3.7.2 Transport numbers
3.8 Supplementary reading
Appendix 3.1 Atomic migration and the diffusion coefficient
Appendix 3.2 The relationship between D and diffusion distance
Appendix 3.3 Ionic conductivity
4 Non-stoichiometry and point defects
4.1 The composition of solids
4.2 Solid solutions
4.2.1 Vegard’s law
4.3 Case study: magnetic spinels
4.4 Non-stoichiometry
4.5 Substitutional impurities
4.5.1 Vacancy formation
4.5.2 Calcia-stabilized zirconia
4.5.3 Interstitial formation
4.6 Density and defect type
4.6.1 Iron monoxide, wüstite, ~FeO
4.6.2 Calcia-stabilized zirconia
4.7 Interpolation
4.7.1 Interstitial alloys and hydrides
4.7.2 Titanium disulphide
4.7.3 Cubic tungsten bronzes
4.8 Defect chemistry
4.8.1 Atomic defects
4.8.2 Charges on defects
4.8.3 Reaction equations
4.9 Point defect interactions
4.10 Supplementary reading
5 Fastion conductors
5.1 Introduction
5.2 The lithium iodide battery
5.3 Disordered cation compounds
5.4 Calcia-stabilized zirconia and related fast oxygen ion conductors
5.4.1 Structure and oxygen diffusion in fluorite structure oxides
5.4.2 Stabilized zirconia electrolytes
5.4.3 Oxygen sensors
5.4.4 Free energy meters
5.4.5 Oxygen pumps and coulometric titrations
5.5 Case study: fuel cells
5.6 The ß-alumina oxides
5.6.1 High energy density batteries: the problem
5.6.2 The structure of ß-alumina
5.6.3 Other ß-alumina related phases
5.6.4 ß-alumina batteries: a solution
5.7 The LixTiS2-Li3N battery: role reversal
5.7.1 LixTiS2: a non-stoichiometric electrode
5.7.2 Li3N: a stoichiometric electrolyte
5.8 Supplementary reading
6 Non-stoichiometry and electronic conduction
6.1 Introduction
6.2 Non-stoichiometry in pure oxides
6.2.1 Metal excess
6.2.2 Oxygen excess.
6.3 The effect of impurity atoms
6.3.1 Impurities in silicon and germanium
6.3.2 Impurities in simple oxides
6.3.3 Impurities in complex oxides
6.4 Electronic conduction in ionic materials
6.5 Thermoelectric effects
6.5.1 The thermoelectric coefficients
6.5.2 The Seebeck coefficient and defect type
6.5.3 The Seebeck coefficient and defect concentrations
6.5.4 The Seebeck coefficient and stoichiometry
6.6 Band theory
6.6.1 Energy bands
6.6.2 Insulators, semiconductors and metals
6.6.3 Point defects and energy bands
6.7 Band conduction and hopping conduction
6.8 Case study: turning an insulator into a metal
6.9 Supplementary reading
Appendix 6.1 Hopping conductivity
Appendix 6.2 The Seebeck coefficient and entropy
Appendix 6.3 The Seebeck coefficient for hopping semiconductors
7 Defects and optical properties
7.1 Colour
7.2 Case study: rubies and ruby lasers
7.3 Transparent electrodes
7.4 Electrochromic films
7.5 Case study: the structure of the F-centre
7.6 Electron and hole centres
7.7 Case study: the search for a colour centre based information storage medium
7.7.1 Information storage
7.7.2 Photochromic calcium fluoride
7.7.3 Information storage on defects
7.8 Colour centre lasers
7.9 Supplementary reading
8 Defects, composition ranges and conductivity
8.1 The equilibrium partial pressure of oxygen over an oxide
8.2 Variation of partial pressure with composition
8.3 Electronic conductivity and partial pressure for Ni1-xO
8.4 Case study: Co1-xO
8.5 Electronic conductivity and partial pressure for Zn1+xO
8.6 Brouwer diagrams
8.6.1 Initial assumptions
8.6.2 Defect equilibria
8.6.3 Equilibrium constants
8.6.4 High X2 partial pressures
8.6.5 Medium X2 partial pressures
8.6.6 Low X2 partial pressures
8.6.7 The complete diagram
8.6.8 Further considerations
8.7 Case study: an experimentally determined Brouwer diagram; CdTe
8.8 Supplementary reading
9 Point defects and planar defects
9.1 Point defects in nearly stoichiometric crystals
9.2 Point defect clusters
9.2.1 Iron oxide, ~FeO
9.2.2 Uranium oxide, UO2+x
9.3 Microdomains
9.4 Point defect ordering and assimilation
9.5 Interpolation
9.6 Planar faults and boundaries
9.7 Crystallographic shear phases
9.7.1 Crystallographic shear in tungsten oxides
9.7.2 Crystallographic shear in titanium oxides
9.7.3 Impurities and CS in WO3 and TiO2
9.8 Chemical twinning
9.8.1 Lead-bismuth sulphosalts
9.8.2 Molybdenum oxides and phosphate bronzes
9.9 Planar intergrowths
9.9.1 Perovskite-related structures in the Ca4Nb4O14-NaNbO3 system
9.9.2 Intergrowth tungsten bronzes
9.10 Case study: the Nb2O5 block structures
9.11 Pentagonal column phases
9.12 Defect-free structures: modulated and incommensurate phases
9.12.1 Vernier structures
9.12.2 Infinitely adaptive compounds
9.12.3 Modulated or incommensurate structures
9.13 Supplementary reading
10 Defects and non-stoichiometry in high temperature superconductors
10.1 Superconductivity and superconductors
10.2 High temperature oxide superconductors
10.3 Superconducting oxides which do not contain copper
10.3.1 LiTi2O4
10.3.2 ВаВіОз-related phases
10.4 High-temperature superconducting copper oxides
10.5 La2Cu04 and related phases
10.5.1 La2CuO4
10.5.2 Substituted La2CuO4 phases
10.5.3 La„+1Cu„O3„+1 and related phases
10.6 Nd2CuO4 electron superconductors
10.7 YBa2Cu3O7 and related phases
10.8 Pb2Sr2YCu3O8
10.9 The Bi, Tl and Hg homologous series of superconductors
10.10 Conclusions
10.11 Supplementary reading
11 Non-stoichiometry: an overview
11.1 Ordering, assimilation and elimination of defects
11.2 Thermodynamics and structures
11.3 Theories and calculations
11.4 Defect structures and configurations
11.5 Surfaces and interfaces
11.6 Molecular dynamics
11.7 Supplementary reading
Formula index
Index of structures
Subject index