Wang Shui-Jinn, Chen Chao-Hsuing, Chang Shu-Cheng, Wong Chin-Hong, Uang Kai-Ming, Chen Tron-Min, Ko Rong-Ming, Liou Bor-Wien
Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China.
Nanotechnology. 2005 Feb;16(2):273-7. doi: 10.1088/0957-4484/16/2/016. Epub 2005 Jan 13.
The thermal annealing conditions in nitrogen ambient for the self-synthesis of tungsten carbide nanowires from sputter-deposited WC(x) films were investigated. Experimental results show that the temperature window for the growth of nanowires lies in the range of 500-750 °C with the corresponding annealing time interval ranging from 2.5 to 0.25 h. The diameter, length, and density of the grown nanowires are in the range of 10-15 nm, 0.1-0.3 µm, and 210-410 µm(-2), respectively. The degree of carbon depletion in the annealed WC(x) films plays a crucial role in determining both the shape and density of the self-synthesized nanowires. Nanowires synthesized at lower temperatures were seen to be smaller in dimension but higher in density. Material analysis reveals that the phase transition from WC to W(2)C arising from decarburization of the WC(x) film during thermal annealing should be responsible for the self-synthesis of nanowires.
研究了在氮气环境中对溅射沉积的WC(x)薄膜进行自合成碳化钨纳米线的热退火条件。实验结果表明，纳米线生长的温度窗口在500 - 750°C范围内，相应的退火时间间隔为2.5至0.25小时。生长的纳米线的直径、长度和密度分别在10 - 15纳米、0.1 - 0.3微米和210 - 410微米(-2)范围内。退火后的WC(x)薄膜中的碳耗尽程度在决定自合成纳米线的形状和密度方面起着关键作用。在较低温度下合成的纳米线尺寸较小但密度较高。材料分析表明，热退火过程中WC(x)薄膜脱碳导致的从WC到W₂C的相变应该是纳米线自合成的原因。
