共查询到20条相似文献,搜索用时 15 毫秒
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Li Wan Bo Tang Xinhong Cheng Yiming Ren Xuefei Zhang Dapeng Xu Haijun Luo Yunmi Huang 《Physica B: Condensed Matter》2009,404(16):2324-2326
Raman scattering intensities of the NiSi Raman-active modes have been calculated with three Raman measurement configurations, which can be used for the symmetry assignment of the NiSi Raman peaks. Raman-active vibrations of the NiSi crystal have also been theoretically studied. Results show that the lattices with Ag and B2g modes vibrate only in the plane normal to the NiSi[0 1 0] direction while the lattices with B1g and B3g modes vibrate only along the NiSi[0 1 0] axis. Based on such study, the relationship between the anisotropic strain distribution in the NiSi thin film and the Raman peak shifts has been briefly discussed. 相似文献
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The room temperature Raman spectrum of silver chlorate single crystal have been investigated. We make an assignment of all the optical phonon and separate out the internal and external modes. The observed ClO-3 internal modes frequencies closely agree with the values obtained by other authors in different materials. 相似文献
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The transmission spectrum of a one-dimensional photonic crystal with structural defects is investigated. An anisotropic layer of a nematic liquid crystal is considered as a defect. The possibility of effective external control of the transmission spectrum of the photonic crystal by changing either the orientational state of the defect liquid crystal layer (for example, using an electric field) or the angle of incidence of light is shown. It is established that the spectral properties of the photonic crystal change radically with a change in the optical characteristics of the defect layer in the vicinity of the temperature phase transition of the nematic liquid crystal to the isotropic state. 相似文献
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Single crystal dixanthinium tetrachlorozincate has been grown from dilute chloridric acid. Polarized Raman spectrum of the single crystalline sample, FT-Raman and FT-IR spectra of the polycrystalline samples have been examined and the bands assigned to the appropriate modes predicted by a factor group analysis for the space group Pmn21. The crystal structure has been confirmed by powder XRD measurements. 相似文献
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K. V. Domoratskii V. I. Pastukhov A. Yu. Kudzin L. Ya. Sadovskaya V. M. Rizak V. A. Stefanovich 《Physics of the Solid State》2000,42(8):1443-1446
Polarized Raman spectra of the Bi2TeO5 single crystal have been investigated for the first time. The group-theoretic analysis of the first-order vibrational spectra is performed. The number of the experimentally observed bands is less than the predicted number of normal modes. The spectral ranges with similar bands are revealed. Some ranges in the spectra of Bi2TeO5 are identified from the spectral data for the materials containing bismuth-oxygen and tellurium-oxygen complexes. 相似文献
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The infrared absorption spectrum of the sodium uranyl acetate single crystal was studied experimentally at room temperature. The group-theoretical method is used to interpret the splitting of several bands in the spectrum into three components. The vibrations noted in the infrared spectrum are associated with types of symmetry.In conclusion, the authors thank Academician AS BSSR A. N. Sevchenko for his unflagging interest in the present investigation. 相似文献
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用普通的教学用Raman谱仪测试了ZnO晶体样品的Raman光谱,得到了ZnO晶体全部的基本振动的频率,观察到了ZnO晶体的方向色散现象。 相似文献
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R. Hanada 《Hyperfine Interactions》1987,34(1-4):205-208
TDPAC spectra of 111 In in a single crystal of Cd are measured as a function of its. orientation relative to the
-direction. The results are compared with the theoretical calculation by Alder et. al. 相似文献
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A photoelectric spectrometer based on a DPS-12 instrument was used to study the luminescence spectrum of single-crystal rubidium uranyl nitrate at T = 77° K. This spectrum is compared to the infrared spectrum of the same specimen. Several of the frequencies of the luminescence spectrum are attributed to vibrations of the coordinate nitrate groups.The authors wish to express their sincere appreciation to Prof. A. N. Sevchenko, Academician of the Academy of Sciences, Belorussian SSR, for his unflagging interest in the present study. 相似文献
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The radical , labelled with 13C in the position shown, has been prepared by X-irradiation of single crystals of . The 13C hyperfine coupling tensor of this radical confirms previous conclusions from a study of the corresponding unlabelled species that the electron is essentially localized on the carbon atom. At room temperature the methylene group undergoes rapid reorientation about the P-C bond while comparison of the 13C tensors at 300 K and 77 K suggests that the barrier to rotation has a strong two-fold component but contains intermediate minima. 相似文献
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单细胞激光共焦拉曼散射光谱由于受扫描条件、样品自身浓度以及样品分子组成等因素的影响,其谱线信噪比较低、荧光背景有时较明显从而导致谱线质量较差.本文主要针对活态单细胞的拉曼光谱进行谱线预处理技术研究用以提高谱线的信噪比、灵敏度及降低荧光背景干扰.首先是宇宙射线的去除,之后进行谱线的归类,这是提高谱线灵敏度的关键步骤;其次... 相似文献
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For the first time the bulk oriented single crystals ZnO:Mn are obtained and the polarized Raman spectra are studied at excitation in the visible and near infrared regions. The resonance enhancing of the Raman scattering by Mn-related modes is found at the visible excitation due to the extra optical absorption in ZnO at the addition of Mn. It is shown that the resonance-enhanced overtone of Mn-related silent modes may be responsible for an appearance of anomalous modes of the A1 symmetry at 500-600 cm−1. A Fermi resonance between the overtone and one-phonon mode is analyzed. 相似文献
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Lattice disorder for 200-keV Sb implantations into silicon has been studied by channeling effect analysis using 400 keV proton backscattering. Implantation and analysis were performed at low temperatures in the same system without warmup. In the temperature region between 85°K and room temperature the disorder production per incident ion at low doses is implantation temperature dependent. Approximately 18,000 silicon scattering centers per incident 200-keV Sb ion are observed for 90°K implantations, and this value is nearly a factor of three greater than at room temperature. Isochronal anneal curves of low fluence, low temperature implantations show, significant annealing below room temperature. The observed disorder production per incident ion decreases with increasing implantation temperature at temperatures 50 to 100°K lower than annealing occurs following 85 or 90°K implants. Strong similarities of the implantation temperature dependence and anneal behavior of the disorder exist for Sb and B implantations into silicon and suggest that much of the lattice disorder produced by ion implantation can be understood in terms of the basic properties of the silicon target material. 相似文献
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Near-infrared and visible reflectance spectrum was measured on the tetrathiafulvalene-chloranil (TTF-CA) crystal at temperatures in the range of 40–290 K. An abrupt change of reflectivity was found at about 80 K, and new dispersions associated with the intramolecular transitions of TTF+ and CA? gradually grew up on lowering temperature below 80 K, indicating the increase of the ionized fraction. 相似文献
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F. Brehat B. Wyncke A. Hadni 《International Journal of Infrared and Millimeter Waves》1981,2(2):333-345
Conclusion Reflectivity of a single crystal sodium nitrate have been measured as a fonction of temperature and crystallographic orientations over a frequency region which spans all infrared active lattice modes. The data have been fitted with a series of five independent oscillators and an overdamped oscillator of A2u symmetry at temperatures between 250 and 276°C. None of them behaves as a soft mode. Our measurements show also the influence of the phase transition on the lattice modes parameters. 相似文献