High frequency FTIR absorption of sio2 si nanowires

... 2003 Abstract An IR absorption measurement of SiO 2 /Si nanowires made by thermal evaporation was conducted. In comparison with SiO 2 nanoparticles, enhancement absorption of SiO 2 /Si nanowires around ... state for Si O vi- bration absorption to cause the increasing of higher frequency absorption in nanowires. Oppo- sitely, the crystalline field effect does not exist...

Ngày tải lên: 16/03/2014, 15:05

... of peaks. One set consists of the Ž.Ž. Ž. 111 , 220 and 311 peaks of Si which are from Ž.Ž. the SiNWs. The other set consists of the 111 , 220 Ž. and 311 peaks of b-SiC which are from the b-SiC nanoparticles. ... second-order peak of Si. The peak of SiC is asymmetric. This is possibly due to the wx nanoscale size effect of the SiC nanoparticles 19,20 . We propose that the g...

Ngày tải lên: 16/03/2014, 15:08

... The diraction rings of crystalline cubic Si and b-SiC could be identi®ed. High resolution TEM images revealed that Si NW with carbon coating consisted of a single crystalline Si core and a sheath of carbon ... structure of the nanowires was con®rmed to consist of a crystalline Si core and a silica outerlayer by using selected- area electron diraction (SAED) pattern (in...

Ngày tải lên: 16/03/2014, 15:04

... with silica (SiO 2 ) films on silicon wafers to provide silicon atoms into growing nanowires. The TiN layers induce the diffusion of silicon and oxygen to the surface by a stress gradient built inside ... December 2003 Abstract Amorphous silica nanowires (a-SiONWs) were produced by direct solid state transformation from silica films. The silica nanowires grow on TiN/Ni/SiO 2 /Si substra...

Ngày tải lên: 16/03/2014, 15:04

... demonstrate a simple method of growing SiNWs. Si nanopowder was used in our work instead of the dangerous gas of silane as the Si source. The synthesis of SiNWs was carried out using a mixture of Si nanoparticles ... preparation of producing SiN Ws, Si nanoparticles were synthesized by cathode arc plasma which is one of the most powerful met hods because of uniform par...

Ngày tải lên: 16/03/2014, 15:13

... Au /Si substrate have an atomic ratio of Si/ O higher than the 1 2 of SiO 2 . On the other hand, the atomic ratio of Si/ O in the SiO x nanowires formed on the Pd–Au /Si substrate is nearly consistent ... The SiO x nanowires on the Au /Si substrate have an atomic ratio of Si/ O higher than the 1 2 of SiO 2 . (b) EDX spectrum from the sample shown in Fig. 2(b). The atomic r...

Ngày tải lên: 16/03/2014, 15:16

... kinetics simulation by numerical solution of the rate equations, (ii) to reproduce some key stages of a real physical experiment. Besides, we will demonstrate a number of advantages of ‘‘the ... growth due to bulk diffusion of silicon atoms from the surface to the catalyst/NW interface. Here, h is the height of the NW and O is the atomic volume of a silicon atom in a silicon lat...

Ngày tải lên: 16/03/2014, 15:18

... composition-dependent Young’s modulus for Ge-core /Si- shell and Si- core/Ge-shell nanowires. Here, the composition is defined as a ratio of the number of atoms of the core to the number of atoms of ... synthesis of core–shell nanowires with different compositions in the past few years [8–10]. Typically, core– shell nanowires consisting of germanium and silicon have been sy...

Ngày tải lên: 16/03/2014, 15:22

... supercell, l Si ( l H )is the chemical potential of an Si (H) atom, n Si (n H ) is the number of Si (H) atoms, and e z is the zero-point energy of Si H vibrations. The value of l Si is equal to ... vapor deposition (CVD) have been shown to be the controlled growth of molecular-scale Si NWs [7]: the high- resolution transmission electron microscopy (HRTEM) has shown tha...

Ngày tải lên: 16/03/2014, 15:37

... precursors. a) The SEM image of Fe 2 O 3 nanowires precursors. b) The SEM image of Fe 2 O 3 nanowires after sintering at 500℃. c) The TEM image of Fe 2 O 3 nanowires at low magnification ... image of Fe 2 O 3 nanowires after sintering at 500℃. (c) TEM image of Fe 2 O 3 nanowires at low magnification (with the inset showing the corresponding SAED pattern). d) TEM imag...

Ngày tải lên: 20/03/2014, 13:05