Effect of Annealing Temperature on the Hardening Mechanism and Nano-mechanical Response of ZnO Single Crystal Wurtzite Phase: A Nanoscale Analysis

The objective of the research was to examine how variations in annealing temperature affect the mechanical characteristics of ZnO single crystal Wurtzite phase. The samples underwent annealing at different temperatures (350, 500, 700, and 800 °C) in a nitrogen environment for a duration of 2 h, in order to enhance the material's flexibility. Subsequently, the specimens underwent Nanoindentation analysis, revealing a decrease in the estimated mechanical properties as the annealing temperature increased. The calculated hardness values (non-ISE region) were consistent with the experimental results. The study also explored the material's hardening behavior, with the findings suggesting that pressure hardening had a greater influence than strain hardening, based on both coefficient values. These findings underscore the significance of annealing temperature in determining the mechanical properties of ZnO single crystal Wurtzite phase, providing valuable insights for the design of applications such as MEMs, NEMs, piezo-electric, and resistive devices.