Figure 2

a Uniaxial tensile stress as a function of tensile strain η3, and the inset reflects the relation between strains η3 and η1. b Elastic constants as a function of stress σ33
a Uniaxial tensile stress as a function of tensile strain η3, and the inset reflects the relation between strains η3 and η1. b Elastic constants as a function of stress σ33