Investigation of the nanomechanical properties in relation to the microstructure of Zn1−xBexTe alloys

A study by nanoindentation has been performed to investigate the variation of the mechanical properties of Zn1−xBexTe alloys as a function of the beryllium content in the range 0≤x≤0.84. Our data show a very marked increase of hardness (H) and a significant increase of the elastic modulus (E) with Be concentration. These trends are related to an increase in the stiffness of the BeTe bond relative to that of the ZnTe bond. Furthermore, discontinuities are unambiguously revealed in the variations of both H and E at the critical Be content of ∼20%. We relate these to Raman studies of the layers’ microstructure and propose an explanation in terms of a percolative behavior.