Online Thesis Search Results

TITLE
DEDICATION
CERTIFICATE
DECLARATION
ACKNOWLEDGEMENT
PREFACE
CONTENTS
1. CRYSTAL GROWTH
1. Introduction
2. Methods of crystal growth
2.1. Solid state growth
2.2. Melt growth
2.3. Growth from solutions
2.4. Growth from vapour phase
3. The role of chemical and geometric parameters on chemical vapour transport
4. Chemical and geometrical parameters
5. Temperature profiles
5.1. Stationary temperature profile
5.2. Linearly time varying temperature profile
5.3. Oscillating temperature profile
6. Advantages of chemical vapour transport
7 Limitations of chemical vapour transport
8.Conclusion
References
2. THERMODYNAMICS OF CHEMICAL VAPOUR TRANSPORT
1. Introduction
2. Models of chemical vapour transport
3. Advantages of theoretical work
4. Relevance of thermodynamical analysis of chemical vapour transport
5. Thermodynamical model
6. Thermodynamical feasibility study with elements as the source material and Iodine as the transporting agent (Cu: In or Al or Ga: S or Se or Te: 12) and (Ag: Ga or In: S or Te: I2) systems
7. Thermodynamical feasibility study with elements as the source material and Hydrogen iodide as the transporting agent (Cu: In or Al or Ga: S or Se or Te: HI) and (Ag: Ga or In: S or Te: HI) systems
8. Thermodynamical feasibility of tungsten diselenide single crystals- An exposition f the model using binary system
8.1 Model and calculation results
9.Conclusion
Refererrces
3. GROWTH PROCESS OF LAYERED TUNGSTEN DISELENIDE
1. Introduction
2. Practical aspects of crystal growth by chemical vapour transport technique
3. Furnace design
4. Temperature measuring devices
5. Dual temperature controller cum recorder
6. Ampoules
7. Vacuum system
8. Ampoule cleaning
9. Loading of transporting agent and feed material
10. Preparation of polycrystalline WSe2
11. Growth of doped and undoped WSe2 using CVT and DVT
Fig. 3.7 Horizontal tubular furnace and sealing unit
12. Effect of temperature gradient on the growth of crystals during chemical vapour transportation
13. Conclusion
Refrrences
4. ELECTRICAL AND STRUCTURAL CHARACTERIZATION
1. Introduction
2. Measurement techniques
2.1. Two probe method
2.2. Van der Pauw method
2.3 Hall measurements
3. Hall effect studies on crystals at room temperature
4. Conductivity studies on pure and doped WSe2 crystals
5. Nature of charge carrier concentration about the transition
6.X-ray powder diffraction technique
7.Energy Dispersive Analysis of X-ray (EDAX)
8.Conclusion
References
5. MICROHARDNESS STUDIES
1. Introduction
2. Methods of hardness test
2.1. Static indentation test
2.2. Scratch test
2.3. Rebound test
2.4. Plaughing test
2.5. Damping test
2.6. Cutting test
2.7. Abrasion test
2.8. Erosion test
3. Rockwell test
4. Brinell test
5. Mayers test
6. Vickers test
7. Knoop test
8. Measurement corrections
9. Experimental details
10. Results and discussions
10.1. Hardness variation
Fig. 5.2 Leitz Miniload 2 hardness tester
Fig. 5.3 lmpression for the load 5gm after etching
Fig. 5.4 lmpression for the load l0gm after etching
Fig. 5.5 lmpression for the load 15gm after etching
Fig. 5.6 Impression for the load 25gm after etching
Fig. 5.7 lmpression for the load 50gm after etching
10.2. Etching studies
10.3. Application of idea of resistance pressure to the crystals
11. Conclusion
References
6. MICROTOPOGAPHICAL STUDIES
1. Introduction
2. Optical microscopy
3. SEM studies
Fig. 6.1 Hexagonal growth spiral
Fig. 6.2 Layer morphology of a bulk crystal
Fig. 6.3 & 6.4 Hexagonal and elongated hexagonal structures
Fig. 6.5 Typical growth patterns on doped crystal
Fig. 6.6 & 6.7 Dislocation groups with large burges vectors
Fig. 6.8 Twisted plate
Fig. 6.9 Cartoon of overlapping growth
Fig. 6.10 Two dimensional growth
Fig. 6.11 Layer stacking sequences
Fig. 6.12 Bunches of layers
Fig. 6.13 Overlapping of layers
Fig. 6.14 Microcrystals on growing face
Fig. 6.15 Typical etch pattern on (0001) plane
Fig. 6.16 6.19Etching behavior
4. Etching studies
4.1. Experimental
5.Conclusion
References
SCOPE OF FUTURE RESEARCH
References