This paper reports that a large amount of Mn-doped ZnO nanorods have been synthesized through thermal evaporation. The morphologies and properties are studied with x-ray diffraction, a scanning electron microscope, tr...This paper reports that a large amount of Mn-doped ZnO nanorods have been synthesized through thermal evaporation. The morphologies and properties are studied with x-ray diffraction, a scanning electron microscope, transmission electron microscope and Raman spectroscope. The results indicate that the manganese atoms occupy the zinc vacancies in the wurtzite lattice of ZnO without forming secondary phases. The exact manganese content has been studied by the x-ray fluorescence spectrum. Meanwhile, the magnetic moment versus temperature result proves that the as-prepared Mn-doped ZnO nanorods show ferromagnetic properties at temperatures as high as 400~K. These studies provide a good understanding of the origin of magnetic properties in diluted magnetic semiconductors.展开更多
In this paper, we report that an electromotive force （EMF） can be induced in a rope of aligned single-walled carbon nanotubes （SWNTs） when water droplets fall on this rope. The magnitude of this EMF depends sensit...In this paper, we report that an electromotive force （EMF） can be induced in a rope of aligned single-walled carbon nanotubes （SWNTs） when water droplets fall on this rope. The magnitude of this EMF depends sensitively on the slant angle of the SWNTs. Most interestingly, both the magnitude and the direction of the induced EFM can be modulated by applying a current to the SWNTs. The concepts of electrical slip and no-slip are proposed and can be quantitatively described by ＂electrical slip resistance＂. This kind of generator does not need any magnet, rotor, etc and shows quite a different operating mechanism and design compared with a conventional large scale hydroelectric power generator.展开更多
基金supported by "973" Program of Ministry of Science and Technology of China (Grant No. 2006CB932402)National Natural Science Foundation of China (Grant Nos. 50702015, 10574034 and 10774032)
文摘This paper reports that a large amount of Mn-doped ZnO nanorods have been synthesized through thermal evaporation. The morphologies and properties are studied with x-ray diffraction, a scanning electron microscope, transmission electron microscope and Raman spectroscope. The results indicate that the manganese atoms occupy the zinc vacancies in the wurtzite lattice of ZnO without forming secondary phases. The exact manganese content has been studied by the x-ray fluorescence spectrum. Meanwhile, the magnetic moment versus temperature result proves that the as-prepared Mn-doped ZnO nanorods show ferromagnetic properties at temperatures as high as 400~K. These studies provide a good understanding of the origin of magnetic properties in diluted magnetic semiconductors.
基金Project supported by the National Basic Research Program of China (Grant No.2006CB932402)the National Natural Science Foundation of China (Grant Nos.50702015,10574034,and 10774032)
文摘In this paper, we report that an electromotive force （EMF） can be induced in a rope of aligned single-walled carbon nanotubes （SWNTs） when water droplets fall on this rope. The magnitude of this EMF depends sensitively on the slant angle of the SWNTs. Most interestingly, both the magnitude and the direction of the induced EFM can be modulated by applying a current to the SWNTs. The concepts of electrical slip and no-slip are proposed and can be quantitatively described by ＂electrical slip resistance＂. This kind of generator does not need any magnet, rotor, etc and shows quite a different operating mechanism and design compared with a conventional large scale hydroelectric power generator.
