The effects of fast neutron irradiation on oxygen atoms in Czochralski silicon （CZ-Si） are investigated systemically by using Fourier transform infrared （FTIR） spectrometer and positron annihilation technique （PA...The effects of fast neutron irradiation on oxygen atoms in Czochralski silicon （CZ-Si） are investigated systemically by using Fourier transform infrared （FTIR） spectrometer and positron annihilation technique （PAT）. Through isochronal annealing, it is found that the trend of variation in interstitial oxygen concentration （[Oi]） in fast neutrons irradiated CZ-Si fluctuates largely with temperature increasing, especially between 500 and 700℃. After the CZ-Si is annealed at 600℃, the V4 appearing as three-dimensional vacancy clusters causes the formation of the molecule-like oxygen clusters, and more importantly these dimers with small binding energies （0.1-1.0eV） can diffuse into the Si lattices more easily than single oxygen atoms, thereby leading to the strong oxygen agglomerations. When the CZ-Si is annealed at temperature increasing up to 700℃, three-dimensional vacancy clusters disappear and the oxygen agglomerations decompose into single oxygen atoms （O） at interstitial sites. Results from FTIR spectrometer and PAT provide an insight into the nature of the [Oi] at temperatures between 500 and 700℃. It turns out that the large fluctuation of [Oi] after short-time annealing from 500 to 700℃ results from the transformation of fast neutron irradiation defects.展开更多
The present study is designed to simulate and study the production of single crystals of semi-organic non-linear optical Glycine Sodium Nitrate (GSN) by using hyper6 software and experimentally by slow evaporation tec...The present study is designed to simulate and study the production of single crystals of semi-organic non-linear optical Glycine Sodium Nitrate (GSN) by using hyper6 software and experimentally by slow evaporation technique. This work has investigated the molecular properties of the crystals using the density functional theory to obtain the infrared spectrum of the crystal by simulation. The FTIR investigation of growing crystal has shown that the spectrum of the GSN crystal compared to simulation evaluation is similar;the only difference is in the range of 1.9% to 2.75% of wavelength peak values. The ultraviolet experimental measurement of the GSN molecule reveals the possibility of non-linear properties due to the spectrum cutoff in the wavelength peak of 301 nm. There was a significantly positive correlation between simulation and experimental assessment.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 50872028)the Natural Science Foundation ofHebei Province,China (Grant No E2008000079)the Specialized Research Fund for the Doctoral Program of Higher Educationof China (Grant No 20050080006)
文摘The effects of fast neutron irradiation on oxygen atoms in Czochralski silicon （CZ-Si） are investigated systemically by using Fourier transform infrared （FTIR） spectrometer and positron annihilation technique （PAT）. Through isochronal annealing, it is found that the trend of variation in interstitial oxygen concentration （[Oi]） in fast neutrons irradiated CZ-Si fluctuates largely with temperature increasing, especially between 500 and 700℃. After the CZ-Si is annealed at 600℃, the V4 appearing as three-dimensional vacancy clusters causes the formation of the molecule-like oxygen clusters, and more importantly these dimers with small binding energies （0.1-1.0eV） can diffuse into the Si lattices more easily than single oxygen atoms, thereby leading to the strong oxygen agglomerations. When the CZ-Si is annealed at temperature increasing up to 700℃, three-dimensional vacancy clusters disappear and the oxygen agglomerations decompose into single oxygen atoms （O） at interstitial sites. Results from FTIR spectrometer and PAT provide an insight into the nature of the [Oi] at temperatures between 500 and 700℃. It turns out that the large fluctuation of [Oi] after short-time annealing from 500 to 700℃ results from the transformation of fast neutron irradiation defects.
文摘The present study is designed to simulate and study the production of single crystals of semi-organic non-linear optical Glycine Sodium Nitrate (GSN) by using hyper6 software and experimentally by slow evaporation technique. This work has investigated the molecular properties of the crystals using the density functional theory to obtain the infrared spectrum of the crystal by simulation. The FTIR investigation of growing crystal has shown that the spectrum of the GSN crystal compared to simulation evaluation is similar;the only difference is in the range of 1.9% to 2.75% of wavelength peak values. The ultraviolet experimental measurement of the GSN molecule reveals the possibility of non-linear properties due to the spectrum cutoff in the wavelength peak of 301 nm. There was a significantly positive correlation between simulation and experimental assessment.
