Nanowires of metal borates

Abstract
Nanowires of metal borates Al 18 B 9 O 33 and MgB 4 O 7 were synthesized by thermal evaporation of mixed powders containing metal oxide ( Al 2 O 3 or MgO) and boron oxide. Typical widths of these nanowires are in the range of 10 to ∼100 nm and lengths are in the range of several to several tens of micrometers. The nanowires were studied using a high-resolution transmission electron microscope equipped with electron energy lossspectrometer and energy dispersive x-ray spectrometer. The metal borate nanowires fabricated in this way are single crystals. It is proposed that these metal borate nanowires are grown in a vapor–solid process, in which both the metal oxide and boron oxide vapors were simultaneously involved.