Indentation size effect in microhardness measurements of Hg _1-xMn_xTe

The effect of surface damaged layer and Te enrichment layer of Hg _1-xMn_xTe on the indentation size were studied experimentally. Based on the results, the indentation size effect (ISE) of Hg_1-xMn_xTe were discussed using different models, including Meyer's law, the power-law, Hays-Kendall approach and the theory of strain gradient plasticity. The results show that surface damaged layer weakens ISE of the wafers, but the Te enrichment layer reinforces it. The minimum test load necessary to initiate plastic deformation for different Hg _1-xMn_xTe wafers increases from 3.11 to 4.41 g with the increase of x from 0.05 to 0.11. The extrapolated surface hardness values of Hg_1-xMn_xTe are 347.21, 374.75, 378.28 and 391.51 MPa and the corresponding shear strength values are 694.53, 749.50, 756.56 and 783.12 MPa for Hg_1-xMn_xTe with the x values of 0.05, 0.07, 0.09 and 0.11, respectively.