Hempel, Tobias: GMR limits for interlayer coupled and pinned trilayers and new concepts for GMR sensors : experimental investigations and computer simulation. 2005
Inhalt
- Preface
- Theory
- Magnetic Parameters and their Units
- GMR-Effect
- Magnetic Anisotropy
- Interlayer Exchange Coupling
- Phenomenological Description
- Applying the RKKY-Theory on IEC
- Quantum Confinement Model
- Survey of the Models to IEC
- Application as Fitting Equation
- Exchange Biasing
- Orange Peel Coupling
- Calculation of GMR(H) and M(H)
- Standard Model for GMR-Calculation
- Enhanced Model for GMR-Calculation
- Calculation of Magnetization Loop
- Phenomenological Law for M(H)
- Experiments and Discussion on Interlayer Coupled and Pinned Magnetic Trilayers
- Introduction
- Definition of Measurable Quantities
- Review on Unpinned Trilayers
- Sample Preparation and Characterization
- Typical Characteristic
- Ideal Thickness of the Magnetic Layers
- Variation of Spacer Layer Thickness
- Structural Analysis
- Magnetic Measurements
- Comparison of Pinned and Unpinned Trilayers
- Conclusion
- Simulation of the GMR-Characteristics
- Model for Magnetization Reversal
- Requirements and Assumptions of the Model
- Model for Coupled and Pinned Trilayers
- GMR and Magnetization Characteristics
- Model for Other Stacking Sequences
- Simplifications for Vanishing Anisotropy
- Simulation Program GMRSim
- Comparison to Lattice Calculations
- Application of the Simulation
- Determination of Input Parameters
- Characteristics and Evaluated Parameters
- Interpretation of the Results
- Comparison to RKKY-like Interaction
- Conclusion
- New Sensor Concepts
- Introduction
- Answer of a Wheatstone Bridge
- Exploitation of Shape Anisotropy
- Initial Considerations
- Test Structures
- Measurement of Resistance
- Measurement of GMR Characteristics
- Results
- Enhancement of Sputter Anisotropy
- Optimized Test Structures
- Interdiffusion by Local Heat-Treatment
- Realization
- Results on Cu/Co-Multilayers
- Results on Cu/NiFe-Multilayers
- Perspective for Local Annealing
- Demonstrator Device for GMR Sensors
- Summary
- Appendix
- Enhanced Stoner-Wohlfarth's Model for Various Systems
- Model for Trilayers
- Model for Doubled Trilayers
- Model for Bottom Spin Valves
- Model for Multilayers
- Enhanced Model for Multilayers
- Overview to Parameters for the Simulations
- Starting Parameters for Simulations
- Source Code of Simulation Kernel
- References
- Publications and Conferences
- List of Figures
- List of Tables
- Acknowledgment