Probing nano-scale mechanical characteristics of individual semi-conducting nanobelts

Quasi-one-dimensional (1D) solid nanostructures, such as nanobelts of semi-conducting oxides, have stimulated considerable interest for scientific research due to their importance in mesoscopic physics studies and their potential applications as nano-devices, nanocantilevers, nanoactuators and nanosensors. A key challenge to todayʹs research is the experimental difficulty in fabricating, manipulating and testing the physical properties of a single nanowire/cantilever whose size is in the nano- to micro-meter range, because the small size (diameter and length) of the object prohibits the applications of the well-established testing techniques. ike oxide nanostructures, so-called nanobelts, were successfully synthesized by evaporating ZnO or SnO2 powders at high temperatures without the presence of a catalyst. Morphology analysis shows the nanobelts have a rectangle-like cross-section with typical widths of several hundred nanometers, width-to-thickness ratios of 5–50, and lengths of hundreds of micro-meters. Nanoindentations were made on individual ZnO nanobelts by using AFM and Hysitron Triboscope indenters. It was shown that the indentation size effect was still obvious for the indentation depth under 50 nm.