Micro- and nanohardness of GaTe single crystals

Abstract

Gallium chalcogenide crystals draw attention of scientists due to their outstanding optical and optoelectric properties. The AIIIBVI crystals have a tendency to lamination due to van der Waals bonds, thus providing a possibility of making some nanometer thick plates parallel to a cleavage plane, and it broadens the scope of applications of these materials.In this regard, studying of mechanical properties is very important. However, substantial anisotropy of elastic and plastic properties restrains such investigations. Especially demanding is studying of mechanical properties of surface layers and correlation between them and mechanical properties of bulk crystals. In this work, the nanohardness HNI = 2.2 ± 0.2 GPa, and microhardness HV = 350 ± 35 MPa of GaTe crystals were measured on {201} cleavage plane. The elastic modulus of nanoindentation obtained from the deformation curve is ENI = 25 ± 0.5 GPa. Serrated deformation and its microstructural mechanism during nanoindentation are discussed. The fracture zone is studied.