Silicon carbide （SiC） is a IV-IV compound semiconductor material with a wide band gap.Semiconductor electronic devices and circuits made from SiC are presently developed for high-temperature,high-power,and high-radi...Silicon carbide （SiC） is a IV-IV compound semiconductor material with a wide band gap.Semiconductor electronic devices and circuits made from SiC are presently developed for high-temperature,high-power,and high-radiation conditions,in which conventional semiconductors cannot be adequately performed.In this paper,SiH4 and C2H2 were used to synthesize SiC nano-whiskers.Metal Ni was the catalyst.SiC nanowhiskers were grown by vapor-liquid-solid mechanism.The effects of the H2 flow rate,growth temperature,catalyst thickness and growth pressure to grow SiC nano-whiskers were studied.3C-SiC thin film and nano-tips can be synthesized by controlling the growth conditions.展开更多
By a novel controlled combustion synthesis method, a large amount of ZnO nano-whiskers with different morphologies like nanotetrapods, long-leg nanotetrapod and multipods, were prepared without any catalysts and addit...By a novel controlled combustion synthesis method, a large amount of ZnO nano-whiskers with different morphologies like nanotetrapods, long-leg nanotetrapod and multipods, were prepared without any catalysts and additives in open air at high temperature. Their morphologies, structures and optical properties were in-vestigated by using SEM, XRD and PL spectrum. The possible growth mechanisms on the ZnO nano-whiskers were proposed in this paper.展开更多
Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD...Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD） analysis, transmission electron microscopy （TEM） and field emission scanning electron microscopy （FE-SEM）. Face scanning energy dispersive spectrum （face scanning EDS） and twodimensional fast Fourier transform （2DFFF） for element distribution were carried out for confirming composition homogeneity. From XRD and TEIVI, the synthesized Fe304 nano-whiskers are of cubic phase with average dimension of 20 nm~ 200 nm （average aspect ratio of 10）. FE-SEM shows that the nanowhiskers without dispersion are interconnected into a network at a scale of 20μm. 2DFFT of the distribution of Fe and O from face scanning EDS confirms the composition homogeneity of the synthesized Fe3O4. Hydrazine hydrate determines the formation of the nano-whiskers, while the possible mechanism is the preferred growth along certain orientation with the aid of ultrasonic treatment.展开更多
文摘Silicon carbide （SiC） is a IV-IV compound semiconductor material with a wide band gap.Semiconductor electronic devices and circuits made from SiC are presently developed for high-temperature,high-power,and high-radiation conditions,in which conventional semiconductors cannot be adequately performed.In this paper,SiH4 and C2H2 were used to synthesize SiC nano-whiskers.Metal Ni was the catalyst.SiC nanowhiskers were grown by vapor-liquid-solid mechanism.The effects of the H2 flow rate,growth temperature,catalyst thickness and growth pressure to grow SiC nano-whiskers were studied.3C-SiC thin film and nano-tips can be synthesized by controlling the growth conditions.
基金the National Natural Science Foundation of China (Grant Nos. 50572010, 50742007 and 10672020)National Defense Founds of China (Grant Nos. 51420205BQ0154 and A2220061080)+1 种基金"863" Project of China (Grant No. 2007AA03Z103)the Scientific Research Foun-dation of Graduate School of BIT (Grant No. AA200802)
文摘By a novel controlled combustion synthesis method, a large amount of ZnO nano-whiskers with different morphologies like nanotetrapods, long-leg nanotetrapod and multipods, were prepared without any catalysts and additives in open air at high temperature. Their morphologies, structures and optical properties were in-vestigated by using SEM, XRD and PL spectrum. The possible growth mechanisms on the ZnO nano-whiskers were proposed in this paper.
文摘Fe3O4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl2.4H2O with N2H4-H2O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction （XRD） analysis, transmission electron microscopy （TEM） and field emission scanning electron microscopy （FE-SEM）. Face scanning energy dispersive spectrum （face scanning EDS） and twodimensional fast Fourier transform （2DFFF） for element distribution were carried out for confirming composition homogeneity. From XRD and TEIVI, the synthesized Fe304 nano-whiskers are of cubic phase with average dimension of 20 nm~ 200 nm （average aspect ratio of 10）. FE-SEM shows that the nanowhiskers without dispersion are interconnected into a network at a scale of 20μm. 2DFFT of the distribution of Fe and O from face scanning EDS confirms the composition homogeneity of the synthesized Fe3O4. Hydrazine hydrate determines the formation of the nano-whiskers, while the possible mechanism is the preferred growth along certain orientation with the aid of ultrasonic treatment.
