Study on single crystal MgB2 nanosheets grown by hybrid physical-chemical vapor deposition

This report is focused on the MgB2 nanosheets which have a hexagonal single crystal structure with variable thickness and different radial dimensions. The nanosheets are fabricated by hybird physical-chemical vapor deposition for the first time, as far as we know, and meanwhile they can be site-specific transferred so as to make physical properties measurement. Results of electrical and magnetic measurements indicate that the nanosheets is superconductive with a Tconset=38 K, Tc (0)=33 K. The images of scanning electrical microscope show that the nanosheets have a nanoscale thickness and have not only a large scale in wildth from several microns to hundreds of microns but also a flat cleaning surface. The selected area electrical diffraction data is consistent with the early report of MgB2 diffraction. According to those results, the single crystal nanosheets with high quality can be surely indentified as MgB2. It suggests a new technique for MgB2 single crystal fabrication, and a zero electrical behavior is observed in nanoscale single crystal MgB2. This could be a new opportunity to make a right material for the afterward research such as flux vortices, nanoscale mechanical properties.