1 Introduction
 1.1 Charge-based Memory Technology
 1.2 Outline of the Thesis
2 Resistive Change Based Memory
 2.1 RRAM Basics
  2.1.1 Resistive-switchable oxides
  2.1.2 Unipolar and bipolar behavior
  2.1.3 Challenges of the RRAM
 2.2 Mechanisms and Models of Resistive Switching
  2.2.1 First attempts of explanation and early models
  2.2.2 Current research progress
 2.3 Conclusions
3 Stochastic Model of the Resistive Switching
 3.1 Switching Mechanism
 3.2 Model Systems Description
 3.3 Electron Hopping and Ion Motion
 3.4 Applications of Stochastic Based Method
  3.4.1 Electron motion simulation
  3.4.2 Modeling of the SET/RESET process
  3.4.3 Hysteresis cycle modeling
4 Magnetoresistive Memory
 4.1 MRAM and STT-MRAM Basics
  4.1.1 Magnetoresistance phenomenon
  4.1.2 Magnetic pillar switching
 4.2 In-Plane and Perpendicular Free Layer Magnetization
  4.2.1 Thermal stability factor
  4.2.2 Switching current
 4.3 Magnetic Cell Architecture
  4.3.1 Single MTJ with one tunnel barrier
  4.3.2 Dual MTJ with two barriers and ultra-thin dual MTJ cell
  4.3.3 Cell utilizing thermally assisted switching mechanism
  4.3.4 Cell utilizing precessional switching mechanism
  4.3.5 Three-terminal MTJ cell
 4.4 Conclusions
5 Macro- and Micromagnetic Approach
 5.1 Landau-Lifshitz-Gilbert Equation
 5.2 Landau-Lifshitz-Gilbert-Slonczewski Equation
  5.2.1 Single reference layer structure
  5.2.2 Two reference layers structure
 5.3 Effective Magnetic Field
  5.3.1 Exchange field
  5.3.2 Anisotropy field
  5.3.3 Demagnetization and magnetostatic field
  5.3.4 Ampere field
  5.3.5 Thermal field
6 Numerical Implementation of Micromagnetic Approach
 6.1 Space Discretization
 6.2 Magnetic Field Discretization
  6.2.1 External field
  6.2.2 Exchange field
  6.2.3 Magnetocrystalline anisotropy field
  6.2.4 Demagnetization and magnetostatic field
  6.2.5 Ampere field
  6.2.6 Thermal field
 6.3 Time Discretization
 6.4 Energy Calculation
7 STT-MRAM Cells Structure Optimization
 7.1 Influence of the Reference Layers
 7.2 Composite Free Layer
  7.2.1 Switching time reduction
  7.2.2 Thermal stability factor calculation
  7.2.3 Switching energy reduction
  7.2.4 Acceleration switching effect
  7.2.5 Standard deviation of the switching time distribution
 7.3 Structure Optimization of the Composite Free Layer
  7.3.1 Switching time and standard deviation
  7.3.2 Thermal stability factor
  7.3.3 Switching energy
8 Magnetization Oscillations in MTJ-based Structures
 8.1 Switching Failure in a MTJ-based STT-MRAM
 8.2 MTJ-based Bias-Field-Free Spin-Torque Oscillator
  8.2.1 MTJ with half-elliptic reference layer
  8.2.2 Two MTJs with shared free layer
9 Summary