Diamond synthesis from carbon nanofibers at low temperature and low pressure.
In this article, we report a new route to synthesize diamond by converting "solid" carbon nanofibers with a Spark Plasma Sintering system under low temperature and pressure (even at atmospheric pressure). Well-crystallized diamond crystals are obtained at the tips of the carbon nanofibers after sintering at 1500 °C and atmospheric pressure. Combining with scanning electron microscopy, transmission electron microscopy, electron-energy loss spectroscopy and Raman spectroscopy observations, we propose the conversion mechanism as follows: the disorder "solid" carbon nanofibers→well crystallined carbon nanofibers→bent graphitic sheets→onion-liked rings→diamond single crystal→the bigger congregated diamond crystal. It is believed that the plasma generated by low-voltage, vacuum spark, via a pulsed DC in Spark Plasma Sintering process, plays a critical role in the low temperature and low pressure diamond formation. This Spark Plasma Sintering process may provide a new route for diamond synthesis in an economical way to a large scale.
School of Physics and Technology, and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072, China.
Chengzhi
C
Luo
School of Physics and Technology, and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072, China.|Laboratory for Quantum Engineering and Micro-Nano Energy Technology, Faculty of Materials and Optoelectronic Physics, Xiangtan University, Xiangtan 411105, China.
Xiang
X
Qi
School of Physics and Technology, and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072, China.|Center for Electron microscopy, Wuhan University, Wuhan 430072, China.
Chunxu
C
Pan
Center for High Pressure Science and Technology Advanced Research (HPSTAR), 1690 Cailun Road, Bldg 6, Shanghai 201203, China.|High Pressure Synergetic Consortium (HPSynC), Carnegie Institution of Washington, 9700 S. Cass Avenue, Argonne, IL 60439, USA.
Wenge
W
Yang