DIFFUSION AND HARDNESS STUDIES IN MERCURY ZINC TELLURIDE

We report studies of self-diffusion, interdiffusion, and hardness measurements in Hg1- xZnxTe (MZT) in order to compare relative properties of Hg1-xCdxTe (MCT) and MZT. Tracer diffusion behavior of MZT is similar to that of MCT, both in mechanism and in terms of diffusion quantities. Interdiffusion behavior in MZT is similar to that of MCT at low x values and shows a significant decrease with increasing x, but is less x dependent at high x values than in MCT. The self and interdiffusion results in MZT at low x values are related with a Nernst-Planck type of equation. The interdiffusion quantities in MZT are only marginally lower than in MCT for the conditions studied. Hardness values are determined as a function of composition in isothermal vapor phase epitaxial (ISOVPE) and horizontal liquid phase epitaxial (HLPE) MCT and MZT using a Vickers tester, a Knoop tester, and a Nanoindenter. There is a substantial increase of the hardness of MZT over that of MCT. Although hardening enhancement by alloying produces bowing in the hardness values as a function of composition in both MZT and MCT, the bowing is significantly more pronounced in the MZT system. In summary, MZT seems to have significant advantages over MCT with regard to improved hardness, but only a marginal difference in diffusion behavior. © 1990, American Vacuum Society. All rights reserved.