Electron Microprobe Analysis and Scanning Electron Microscopy in Geology

Cover......Page 1
Half-title......Page 3
Title......Page 5
Contents......Page 6
Preface......Page 13
Acknowledgments......Page 15
1.2 Scanning electron microscopy......Page 17
1.3 Geological applications of SEM and EMPA......Page 18
1.4.2 Proton-induced X-ray emission......Page 20
1.4.4 Auger analysis......Page 21
1.4.6 Laser microprobe methods......Page 22
2.2 Inelastic scattering......Page 23
2.3 Elastic scattering......Page 24
2.3.1 Backscattering......Page 25
2.5 X-ray production......Page 27
2.5.2 Characteristic X-ray spectra......Page 28
2.6 X-ray absorption......Page 32
2.8 Cathodoluminescence......Page 33
2.9 Specimen heating......Page 35
3.2 The electron gun......Page 37
3.3 Electron lenses......Page 39
3.3.1 Aberrations......Page 41
3.5 Column alignment......Page 43
3.6 Beam current monitoring......Page 44
3.7 Beam scanning......Page 45
3.8 The specimen stage......Page 46
3.9 The optical microscope......Page 48
3.10 Vacuum systems......Page 49
3.10.2 Low-vacuum or environmental SEM......Page 50
3.11.1 Secondary-electron detectors......Page 51
3.11.2 Backscattered-electron detectors......Page 52
3.12.1 Auger electrons......Page 53
3.12.2 Cathodoluminescence......Page 54
3.12.3 Electron-backscatter diffraction......Page 56
4.2 Magnification and resolution......Page 57
4.3.1 Working distance......Page 58
4.4.1 Secondary-electron images......Page 59
4.4.2 Topographic contrast in BSE images......Page 61
4.4.3 Spatial resolution......Page 65
4.4.5 Stereoscopic images......Page 68
4.5 Compositional images......Page 69
4.5.1 Atomic-number discrimination in BSE images......Page 71
4.6.1 Statistical noise......Page 77
4.6.2 Specimen charging......Page 78
4.6.4 Astigmatism......Page 79
4.7.1 Digital image processing......Page 80
4.7.2 False colours......Page 83
4.8.1 Absorbed-current images......Page 84
4.8.3 Electron-backscatter diffraction images......Page 86
4.8.4 Cathodoluminescence images......Page 89
4.8.6 Scanning Auger images......Page 93
5.2.1 Solid-state X-ray detectors......Page 94
5.2.2 Energy resolution......Page 96
5.2.3 Detection efficiency......Page 97
5.2.4 Pulse processing and dead-time......Page 98
5.2.5 Spectrum display......Page 100
5.2.6 Artefacts in ED spectra......Page 102
5.3.1 Bragg reflection......Page 104
5.3.2 Focussing geometry......Page 106
Defocussing effects......Page 107
5.3.3 Design......Page 108
5.3.4 Proportional counters......Page 110
Pulse-height analysis......Page 111
5.3.5 Pulse counting and dead-time......Page 112
5.4 A comparison between ED and WD spectrometers......Page 113
6.2 Digital mapping......Page 115
6.3 EDS mapping......Page 116
6.5 Quantitative mapping......Page 118
6.7 Colour maps......Page 120
6.8 Modal analysis......Page 121
6.10 Three-dimensional maps......Page 125
7.2 Pure-element X-ray spectra......Page 126
7.3 Element identification......Page 129
7.5 Quantitative WD analysis......Page 131
7.5.2 Overlap corrections......Page 133
7.5.3 Uncorrected concentrations......Page 134
7.6.1 Background corrections in ED analysis......Page 136
7.6.3 A comparison between ED and WD analysis......Page 137
7.7.1 Atomic-number corrections......Page 138
7.7.2 Absorption corrections......Page 139
7.7.3 Fluorescence corrections......Page 140
Boundary fluorescence......Page 141
7.7.5 The accuracy of matrix corrections......Page 142
7.8.1 Unanalysed elements......Page 143
7.9 Treatment of results......Page 144
7.9.1 Polyvalency......Page 145
7.9.2 Mineral formulae......Page 146
7.10 Standards......Page 147
7.10.1 Standardless analysis......Page 151
8.1 Light-element analysis......Page 152
8.1.1 Chemical bonding effects......Page 153
8.1.3 Application of multilayers......Page 154
8.3 Choice of conditions for quantitative analysis......Page 155
8.4 Counting statistics......Page 156
8.4.1 Homogeneity......Page 157
8.6 The effect of the conductive coating......Page 158
8.7.1 Heating......Page 159
8.7.2 Migration of alkalies etc.......Page 160
8.9 Special cases......Page 162
8.9.2 Broad-beam analysis......Page 163
8.9.3 articles......Page 164
8.9.5 Thin specimens......Page 165
8.9.6 Fluid inclusions......Page 166
8.9.7 Analysis in low vacuum......Page 167
9.1.2 Drying......Page 168
9.1.4 Replicas and casts......Page 169
9.1.5 Cutting rock samples......Page 170
9.2.2 Embedding......Page 171
9.2.4 Grain mounts......Page 172
9.2.5 Standards......Page 173
9.4 Etching......Page 174
9.5 Coating......Page 175
9.5.1 Carbon coating......Page 176
9.5.3 Sputter coating......Page 177
9.5.4 Removing coatings......Page 178
9.6.1 Specimen \'maps\'......Page 179
9.7 Specimen handling and storage......Page 180
Appendix......Page 181
References......Page 198
Index......Page 206