Growth and characterization of dumbbell-shaped MgO nanowhiskers

By depositing Mg vapor generated by carbothermal reduction onto boron powder, dumbbell-shaped MgO nanowhiskers were obtained. The diameters of these whiskers and balls are 50–150 nm and 1.4–2 μm, respectively. EDS analysis results reveals that the compositions of whiskers are Mg, O and small amount of B and Si. While the compositions of balls are Si, O and small amount of Al, B, C, Mg, K, Ca. SEM and TEM observation indicates that interfaces between balls and whiskers are very smooth. Experimental result shows that whiskers should grow in advance, and then balls grew by depositing silicon oxide and other vapor species onto the surface of these whiskers. The presence of silicon oxide was considered to play a key role in the formation of this peculiar morphological product.