Effect of BN coatings on oxidation resistance and field emission of SiC nanowires

We compare the effects of BN coatings on antioxidation ability and field emission properties of SiC nanowires. Under oxidizing condition, SiC nanowires without BN coatings are cracked into nanoparticles or almost fully converted into SiO2 nanowires at the temperature above 800 K, depending on the crystallization degree of SiC nanowires. The BN coatings effectively improve the antioxidation ability of SiC nanowires due to the excellent chemical stability of BN at high temperature. At a temperature higher than 1273 K, the coated SiC nanowires still exhibit strong oxidation resistance. For the effect on electron emission, the BN coatings also reduce the turn-on field of SiC nanowires from larger than 10 V/mum to lower than 6 V/mum. The explanation for the improvement of field emission characteristics has been presented. (C) 2003 American Institute of Physics.