Mechanical properties and indentation-induced damage of high-quality ZnO microwires

In this paper, we aim to discover the mechanics-related novel phenomena on high-quality ZnO microwires through nanoindentation method. The mechanical property parameters of ZnO microwires were determined and a distinctive creep damage phenomenon was revealed. By using the cycles load mode in the nanoindentation experiments, the indentation size effect was demonstrated to exist in the ZnO microwires: the elastic modulus ranged from 65.9 GPa to 12.3 GPa and the hardness changed from 11.1 GPa to 1.8 GPa with the increase of indentation depth. Furthermore, the indentation-induced mechanical and electrical damage caused a permanent plastic deformation and an increase of 41% in the longitudinal conductance of the ZnO microwires.

Indentation-induced mechanical and electrical damage.Figure optionsDownload as PowerPoint slideHighlights
► ZnO microwires acting as building blocks in MEMS are grown by a CVD method.
► The nanoindentation experiments show creep damage and indentation size effect.
► The mechanical and electromechanical damages are observed.
► Indentation-induced increase of conductance is explained by piezoresistance effect.