4  Critical Thickness

4.1 Introduction
4.2 The critical thickness criterion
4.2.1 Work done by the misfit strain
4.2.2 Dislocation energy
4.2.3 A straight dislocation at the interface of anisotropic materials
4.2.4 The critical thickness models
4.3 Impact of the anisotropy on the critical thickness criterion
4.4 The critical thickness according to Willis, Jain and Bullough
4.5 Overall comparison of various effects on the predicted critical thickness
4.6 Comparison between theoretical and experimental critical thicknesses
4.7 Summary