Analysis of the extended defects in 3C-SiC.pdf - Nelson Mandela ...

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90 determine the orientation of the micrograph accurately since it is known that the stacking fault is lying on the {111} planes. The dislocation has a zig zag image character indicating that the dislocation line is inclined extending most probably from top to bottom of the foil. Also the projected image of the dislocation line is perpendicular to the fringes of the stacking fault. All of these facts along with the visibility and invisibility of the defect using the different 220 reflections pointed towards the dislocation being a 60° type commonly found in zinc-blende structures with the Burgers vector of the type ½ and the dislocation line in a direction making an angle of 60° with the Burgers vector. However the projected length of the dislocation is 397 nm, which gives a foil thickness of 561 nm by using the beam direction [111] with the dislocation line [110]. This foil thickness is too thick to be electron transparent. The geometrical setup used is shown in Fig. 7.17. Fig. 7.17. The geometrical setup used to infer the foil thickness from an assumed dislocation line direction Next the foil thickness was determined by using CBED. The CBED micrograph taken of the area of the dislocation is shown in Fig. 7.18.
Fig. 7.18. CBED pattern taken of the area of interest using a 220 reflection 91 From the figure a line profile was obtained using a Matlab method developed for this purpose along the line indicated. This was done to aid in the identification of the positions of the minima’s and maximums used in the calculations. The profile is shown in Fig 7.19 with identifications of the maximums and minima’s shown.
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Analysis of the Extended Defects in
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My sincere thanks to the following
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OPSOMMING Hierdie dissertasie hande
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4.2.5. Two-Beam Scattering Matrix 4
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Dedicated to my wife and parents
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SUMMARY The dissertation focuses on
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CONTENTS Chapter 1: INTRODUCTION 1
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1 CHAPTER ONE INTRODUCTION Silicon
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2.1. Introduction 3 CHAPTER TWO OVE
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2.2.2 The Zinc-Blende Structure 5 T
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2.3 Point Defects, Defect Migration
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v m Em vm0 exp( ) (2.2) kT 9 wher
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11 explained and the concept of par
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13 Straight dislocations furthermor
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2.5 Partial Dislocations and Slip 1
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17 Fig. 2.13. The geometrical setup
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19 extrinsic stacking faults are th
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2.8 Twinning 21 Twinning is a proce
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23 Fig. 2.20. The process of vacanc
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S n Td (3.2) 25 and is also referr
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27 where a = a0(Z1 2/3 + Z2 2/3 ) -
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29 Using this expression, curves of
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31 As stated previously hard-sphere
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33 where A is the atomic weight. Th
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35 a vacancy dislocation loop if th
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37 Fig. 4.1. (a) A wave incident on
Page 53 and 54: 39 Consider Fig. 4.2 which illustra
Page 55 and 56: 41 V0 is the mean inner potential o
Page 57 and 58: 43 beam left-hand side g' = 0 g' =
Page 59 and 60: 45 In addition another set of indep
Page 61 and 62: 47 When this is incorporated into t
Page 63 and 64: S ( s , z ) e T i Se ( / 0 )
Page 65 and 66: z0 z2 . xn cos and (4.47) D 1 proj
Page 67 and 68: 5.1 Introduction 53 CHAPTER FIVE LI
Page 69 and 70: 55 different orientations. The inte
Page 71 and 72: 57 Furthermore Pirouz et al. (1987)
Page 73 and 74: 59 intersection of the fault, the f
Page 75 and 76: 61 each nuclei because of the low s
Page 77 and 78: 63 (2000) found that subsequent ann
Page 79 and 80: 6.3.1 Ion Range and Defect Producti
Page 81 and 82: 67 Fig. 6.3. Total number of displa
Page 83 and 84: 7.1 Introduction 69 CHAPTER SEVEN R
Page 85 and 86: Fig. 7.2. Simulated diffraction pat
Page 87 and 88: 73 Fig. 7.3. A HRTEM image of the S
Page 89 and 90: 75 Fig. 7.5. The stacking fault sel
Page 91 and 92: (Si/ni) 2 0.000018 0.000016 0.00001
Page 93 and 94: 79 may be concluded that the initia
Page 95 and 96: 81 Fig. 7.11. Bright field TEM micr
Page 97 and 98: 83 Fig. 7.12 which was obtained by
Page 99 and 100: 85 Fig. 7.13. Bright-field TEM micr
Page 101 and 102: 87 (a) (b) Fig. 7.15. The (a) exper
Page 103: 89 In the following paragraphs the
Page 107 and 108: 93 Table 7.5. The measured paramete
Page 109 and 110: 7.4.2 Results 95 Fig. 7.22. Bright-
Page 111 and 112: 97 Twin platelets on {111} planes
Page 113 and 114: 99 REFERENCES Blumenau, A.T., Jones
Page 115 and 116: 101 Hull, D., Bacon, D.J. : (1984)
Page 117: 103 Smith, D.J., Jepps, N.W. and Pa
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