One-dimensional nickel borate nanowhiskers: characterization, properties, and a novel application in materials bonding

The growth of nickel borate [Ni-3(BO3)(2)] nanowhiskers was successfully achieved by simply heating a mixture of nickel and boron oxide (B2O3) powders at 950 degrees C in air. The products were characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The synthesized nanowhiskers, with diameters of 150-500 nm and lengths of 10-30 mm, possessed high aspect ratio, and were found to grow along the [012] crystallographic direction. Stacking faults, hollow interiors, and high-energy facets were found occasionally. The high-temperature stability of Ni-3(BO3)(2) nanowhiskers was investigated. The nanowhiskers partially decomposed after being treated at 1200 degrees C. Based on the solid-liquid-solid mechanism, the possible growth process of Ni-3(BO3)(2) nanowhiskers was discussed. Ni-3(BO3)(2) nanowhiskers were successfully used for bonding nickel in air. The nickel/nanowhisker/nickel joint was characterized in detail by scanning electron microscopy and laser scanning confocal microscopy.