CHEMICAL VAPOR DEPOSITION OF THIN FILM MATERIALS FOR ...

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MgAl2O4 substrate is showed in Fig.46. Lattice fringes could be clearly seen from both {220} and {040} planes. The dark area might be from antiphase boundaries as has been reported by R. Datta, et. al..[163] The area in the red box of Fig.46(a) is Fourier filtered to exhibit the diffraction information only from the {040} planes. Break of periodicities has been found and marked with red circles in Fig.46(b). The lattice mismatch and difference of thermal expansion coefficients could both contribute to the presence of irregular lattice planes at the interface of thin film growth. Fig. 45. Bright field TEM image of nickel ferrite on MgAl2O4 deposited under 600˚C. The image is taken under two beam conditions with g = . Courtesy of Dr. R Datta for taking the TEM image. Fig. 46. (a) HRTEM image of the interface between nickel ferrite film and MgAl2O4 substrate; (b) Fourier transform of the area in the red box of the HRTEM image, the as left lattice fringes are from {040} planes. Courtesy of Dr. R Datta for taking the HRTEM images. 89
We have used an AGM (Alternating Gradient Magnetometer) to measure the room temperature magnetic properties of the as-deposited films on MgAl2O4 substrate. The saturation magnetization values are 257, 261, 284 and 299 emu/cm 3 for films grown at 500, 600, 700 and 800˚C, respectively. In spite of the increased surface roughness of the sample grown at 800˚C, its saturation magnetization value is very close to the bulk value of 300 emu/cm 3 . This may be attributed to the increased degree of texture with increasing deposition temperature, as indicated by the results of the ω scan. Fig.47 shows the hysteresis loops of samples deposited at 500˚C and 800˚C, with an increase in saturation moment observed for the film grown at the higher temperature. Variations in the values of the saturation magnetization and coercivity versus deposition temperature are plotted as insets in Fig.47. While the saturation moment increases steadily with increasing deposition temperature to approach the bulk value, the film coercivity initially increases and then decreases with increasing deposition temperature. Various factors can contribute to the change of coercivity, such as stoichiometry deviation, cation ordering, strain and grain size. Among these, grain boundaries can act as pinning sites for magnetic domain 90
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CHEMICAL VAPOR DEPOSITION OF THIN F
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ABSTRACT Chemical vapor deposition
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DEDICATION This dissertation is ded
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φ In-plane tilt angle of X-ray dif
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ACKNOWLEDGMENTS It is my pleasure t
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CONTENTS ABSTRACT .................
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3.2.1 Introduction ................
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LIST OF TABLES Table 1. Hafnium ami
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indicated by the complex FMR curve.
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Fig. 49. Ferromagnetic resonance cu
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growth rate, good step coverage and
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growth of thin film oxides due to t
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one can uniformly deliver precursor
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for the next reaction step as shown
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Fig. 3. Schematic of a typical dire
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is predominantly dependent on syste
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J r J A -D n b-n 0 δ n or for the
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surface passivation with certain in
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ay spectroscopy (EDS), Wavelength d
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incidence angle is larger than cert
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epresenting those characteristic ph
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1.2.3.3 X-ray Diffraction (XRD) X-r
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exhibit diffraction peaks in the no
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(nanometers to tens of nanometers),
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strongest absorption of microwave s
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pinch-off to indicate the lack of a
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coupling is from unbound ferrite-fe
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diffusion barrier material in micro
Page 57 and 58: Fig. 14. A cross sectional scanning
Page 59 and 60: In spite of the same spinel structu
Page 61 and 62: ferrites has been investigated exte
Page 63 and 64: systems is showed in Fig.18.[83] As
Page 65 and 66: precursor vaporization process, e.g
Page 67 and 68: CHAPTER 3. PLASMA ENHANCED ATOMIC L
Page 69 and 70: the initial surface chemistry for t
Page 71 and 72: delay time of 2 seconds between spe
Page 73 and 74: Kcal/mol respectively. The stronger
Page 75 and 76: negative slope) behavior in the pum
Page 77 and 78: the existence of both physisorbed a
Page 79 and 80: decomposition products (Hf-H) and g
Page 81 and 82: dried by ultra high purity N2 gas.
Page 83 and 84: pressure for XPS analysis is around
Page 85 and 86: Hf and N elements, incorporation of
Page 87 and 88: [150,151] This is a unique feature
Page 89 and 90: software. The thickness results are
Page 91 and 92: CHAPTER 4. DIRECT LIQUID INJECTION
Page 93 and 94: film growth region. The properties
Page 95 and 96: solution was accurately controlled
Page 97 and 98: size). For the rocking curve analys
Page 99 and 100: oxygen does not participate in the
Page 101 and 102: ecause vapor velocity cannot be cha
Page 103 and 104: Fig. 40. Cross-sectional view by fi
Page 105 and 106: the MgAl2O4 substrate confirms cube
Page 107: pattern. Fig.44(b) has diffraction
Page 111 and 112: as derived equations for different
Page 113 and 114: deposited at 600˚C is the lowest.
Page 115 and 116: wave states degenerate with the FMR
Page 117 and 118: Fig. 53. ϕ-scan of nickel ferrite
Page 119 and 120: Surface roughness characterized by
Page 121 and 122: Fig. 56. X-ray diffraction θ-2θ c
Page 123 and 124: 4.4 Conclusion In summary, we have
Page 125 and 126: CHAPTER 5. DIRECT LIQUID INJECTION
Page 127 and 128: eaction zone of the tube furnace is
Page 129 and 130: Fig. 58. X-ray diffraction characte
Page 131 and 132: interface. This phenomenon probably
Page 133 and 134: 6.1 Conclusion CHAPTER 6. CONCLUSIO
Page 135 and 136: the temperature range of 600˚C to
Page 137 and 138: such as PMN-PT and PZN-PT. CVD proc
Page 139 and 140: [18]. L. S.-J. Peng, X. X. Xi, B. H
Page 141 and 142: [54]. B. O. Johansson, J. -E. Sundg
Page 143 and 144: [96]. J. D. Adam, S. V. Krishnaswam
Page 145 and 146: [136]. J. Zhao, V. Fuflyigin, F. Wa
Page 147 and 148: APPENDIX A: LabVIEW PROGRAM FOR PEA
Page 149 and 150: APPENDIX B: TDMAH MOLECULAR STRUCTU
Page 151 and 152: H 18 B19 2 A18 1 D17 H 18 B20 2 A19
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