Preparation of novel saw-toothed and riblike alpha-Si3N4 whiskers.
alpha-Si(3)N(4) whiskers with novel saw-toothed and riblike structures have been synthesized in a high yield by a carbothermal reduction and nitridation route. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). The results show that the saw-toothed whiskers with one smooth surface and another toothlike surface have lengths about several tens of microns and widths in the range of 600-1200 nm. The riblike whiskers are composed of Si(3)N(4) rod-arrays, which grow closely packed perpendicular to the central axial whiskers with uniform diameter and length. The growth mechanism of the products can be considered as a combination of VS mechanism and secondary epitaxial nucleation process. The photoluminescence (PL) spectrum of the whiskers shows a strong blue light emission peak at 406 nm and a weak peak at 485 nm, suggesting their potential applications in light and electron emission devices.
Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
Yajie
Y
Xu
Chuanbao
C
Cao
Zhuo
Z
Chen
Jie
J
Li
Fuchi
F
Wang
Hongnian
H
Cai