The Si3N4 microcrystals with a hollow sphere structure were prepared by using the simple heat treatment of the Si3N4 flakes, which were prepared by using the cathode arc plasma. The products were characterized by XRD, SEM and TEM. The photoluminescence (PL) spectrum of the Si3N4 nano-microsphere was studied. The obtained Si3N4 microcrystals, which show a hollow sphere structure, are up to several nanometers in diameter. During the process, the heat treatment and Ni catalyst play a key role in the forming structure and morphology. This result provides a possibility for mass producing Si3N4 microcrystals.
Amorphous diamond nanorod arrays with excellent field emitting have been fabricated firstly on the AAO template by the filtered cathodic arc plasma technique. Microscopic analysis has displayed that the nanorods are very uniformly distributed, and the density is very high up to ～109 cm-2. The nanorod arrays are found to have an extremely low turn-on field of 0.16 V/μm, which is lower than other reported materials, and a high- emission current density of 180 mA/cm2 under an applied field of 2 V/μm can also be obtained. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and filed emitting tester are employed to characterize the nanorod arrays. The field emission mechanism of the nanorod arrays is also discussed.
YAN Pengxun LI Xiaochun XU Jianwei LI Xin LI Chun LIU Yang
