Observation of two- and three-dimensional magnesium oxide nanostructures formed by thermal treatment of magnesium diboride powder

A simple thermal treatment has been used to produce a variety of elongated single crystalline magnesium oxide nanostructures. Incipient evaporation of a magnesium diboride starting powder combined with a mixed oxygen/argon process gas provided the constituents for nanostructure growth. Electron diffraction and energy dispersive x-ray spectroscopy confirm the single crystalline nature and chemical composition of the objects, and the atomic surface plane is observed to be of the (001) type. Transmission electron microscopy and scanning electron microscopy reveal several MgO morphologies including linear nanobelts and two- and three-dimensional entities that contain approximately ninety degree angles. Atomic steps are observed on the inner edges of these angles, but are absent from the outer rims. The experimental conditions used to form these nanoscale materials and possible applications are described. (C) 2002 American Institute of Physics.