Determination of elasto-plastic properties of semiconducting Hg_1-xCd_xSe using nanoindentation

The nanoindentation technique has been applied to study the elasto-plastic properties and characteristics of Hg1-xCdxSe grown on GaSb (2 1 1)B substrates with molecular beam epitaxy. The Young's modulus of Hg1-xCdxSe samples is determined to be 38 (+/- 3), 44 (+/- 6), 52 (+/- 7), 60 (+/- 6), and 54 (+/- 5) GPa, while the hardness is determined to be 0.67 (+/- 0.05), 0.77 (+/- 0.09), 0.93 (+/- 0.05), 1.02 (+/- 0.04), and 1.09 (+/- 0.07) GPa for x values of 0.19, 0.24, 0.31, 0.36, and 0.46, respectively. The indentation elasto-plastic response of Hg1-xCdxSe samples is purely elastic for small indentation loads corresponding to penetration depths below similar to 15 nm. For deeper indentations, the initiation of plastic deformation has been found to be marked by "pop-in" events observed in the recorded load-penetration curves, which has previously been linked with homogenous nucleation of dislocations. Beyond the "pop-in" event depths, Hg1-xCdxSe samples present a high degree of plasticity (80---90 %), which is observed to be inversely correlated with the composition ratio x value in the Hg1-xCdxSe material system.