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1.
Electron diffraction data have been used as a constraint in the determination of force field for Tl2F2 having planar rhombic structure. The L-F approximation method, recently given by us, has also been applied to evaluate force
constants for thallous halide dimers,e.g. T12F2 and T12Cl2. The results have been compared with the available experimental data in order to check the validity of the present work.
It is concluded that non-bond experimental mean amplitudeU
1...Tl for Tl2F2 is capable of fixing the force field and L-F approximation gives reasonably good force fields for the two thallous halide
dimers now under study. 相似文献
2.
Keinosuke Hamada 《光谱学快报》2013,46(6-7):537-543
There are two possible configurations for H2O, linear(D∞h) or bent(C2v). For a C2v′, the three bands ν1′ ν2 and ν3 should appear in both Raman and infrared. For a D∞h. however, the ν1, band should appear in only Raman and the ν2 and ν3 bands, in only infrared, that is, a principle of mutual exclusion of Raman and infrared should hold. The present author concludes that H2X and D2X(X=O, S, Se, Te) have a linear D∞h. structure, since the obtained spectra show mutual exclusion of Raman and infrared. 相似文献
3.
4.
The pressure- and photo-induced phase transition in mixed-valence gold complexes of Cs2Au2X6 (X = Cl, Br, and I) has been investigated by means of the Raman scattering. The Raman-active Au-X stretching modes were deactivated by the pressure, which indicates a pressure-induced phase transition from the mixed-valence (MV) state to the single-valence (SV) state. The electronic phase diagrams of Cs2Au2X6 (X = Cl and Br) as a function of pressure and temperature have been derived. A photoinduced phase transition from the MV state to the SV state has been found for Cs2Au2Br6. The observed time behavior accompanying this phase transition is successfully interpreted by the Avrami model, indicating the three-dimensional character of the MV cluster growth. 相似文献
5.
Si3Xn (X=C,O,N;n=1,2)团簇的密度泛函研究 总被引:1,自引:0,他引:1
使用密度泛函理论(DFT)的杂化密度泛函B3LYP方法在6-31G*基组水平上对Si3Xn(X=C,O,N;n=1,2)团簇各种可能的构型进行几何结构优化,预测了各团簇的最稳定结构.并对最稳定结构的电子结构、振动特性、成键特性和电荷特性等进行了理论研究.结果表明团簇的几何结构都是平面结构,通常Si3X2出现是Si-X键,较少出现X-X键;而Si3X中出现Si-X键和Si-Si键共存,Si3Xn(X=C,O,N;n=1,2)团簇的电荷布局分布表明这种电荷转移的作用使得团簇中所有X原子呈负电性,Si原子显正电性.处于不同位置的Si原子呈不同大小布局数,而且由于Si3X2的对称性,2个X负电性相同. 相似文献
6.
Daiyu Kondo Akio Kawabata Masahiro Horibe Mizuhisa Nihei Yuji Awano 《Superlattices and Microstructures》2003,34(3-6):389
We have succeeded in making peapod structures with vertically aligned multi-walled carbon nanotubes (MWNTs), grown on a silicon substrate using hot filament chemical vapor deposition. Opening the tips of the MWNTs was performed at 600 C using oxygen and then C60 molecules were deposited on them to fill their inner spaces. We confirmed that the MWNTs were open at the tips and filled with C60 molecules using transmission electron microscopy. In addition, it has been determined that MWNTs can be filled with other materials, such as molybdenum oxide. 相似文献
7.
The Raman, infrared and 1H-NMR spectra of (CH3)3 -X-Si (CH3)3 (X=O,S,Se,Te) were measured, and the assignment was carried out by comparison with those of the structurally related compounds, (CH3)3 SiCl and (CH3)3 Si-Si (CH3)3. The vibrational spectra of (CH3)3 Si-X-Si (CH3)3 can be interpreted in terms of a non-rigid D3d symmetry with internal rotations, because those of skeletones of the molecules indicate the lack of coincidence between Raman and infrared frequencies. The 1H-NMR spectra also support a non-rigid D3d model, because only one band for CH3 group appears. 相似文献
8.
Søren K. Klitgaard Lærke T. Haahr David Hansen Claus H. Christensen 《Surface science》2007,601(9):L35
The observation of chain-like structures of self-assembled C60 molecules on HOPG surfaces at room temperature in aerial atmosphere by means of scanning tunneling microscopy is reported. The ca. 2.5 nm center-to-center distance between two fullerene molecules is much larger than in the close-packed layered or film structures of C60 usually found on HOPG surfaces. 相似文献
9.
在C60单晶超高真空解理面上制备C60的Rb填隙化合物薄膜.用同步辐射光电子能谱研究了相衍变过程.观察到对应于固溶相、Rb1C60和Rb3C60的电子态密度分布.当数纳米厚Rb3C60薄膜在C60单晶(111)解理面形成后,室温条件下进一步沉积Rb至样品表面不产生fcc到bct或bcc结构相变.C60
关键词:
4C60和Rb5C60吸附相')" href="#">金属性Rb4C60和Rb5C60吸附相
60单晶')" href="#">C60单晶
相衍变
同步辐射光电子能谱 相似文献
10.
11.
D.V. Suetin 《Physica B: Condensed Matter》2009,404(20):3544-3549
First-principles FLAPW-GGA calculations have been performed with the purpose to determine the peculiarities of the structural, electronic, magnetic properties and stability for a family of related η carbides M3W3C and M6W6C (where M=Fe and Co). The geometries of all phases were optimized and their structural parameters, theoretical density, cohesive and formation energies, total and partial densities of states, atomic magnetic moments have been obtained and analyzed in comparison with available theoretical and experimental data. 相似文献
12.
利用脉冲激光沉积的方法制备掺铒 Si/Al2O3多层结构薄膜,获得了由纳米结构的Si作为感光剂增强的Er3+在1.54 μm高效发光.利用拉曼散射、高分辨透射电镜和光致发光测量研究了在不同退火温度下(600—1000 ℃)纳米结构Si层的结晶形态变化,及对Er3+在1.54 μm的发光的影响特征.研究发现最佳发光是在退火温度600—700 ℃.在这个条件下纳米Si的尺寸和密度,Si和Er的作用距离以及Er3+
关键词:
铒
纳米硅
能量转移
氧化铝 相似文献
13.
在广义梯度近似(GGA)和GGA+ U(在位库仑势)下,采用第一性原理方法系统地研究了三元过渡金属硼碳化合物YPd3 X(X=B,C)的晶体结构、弹性性质、电子结构和成键特性.计算的晶格参数和体弹性模量均与报道的实验结果吻合,而YPd3 X(X=B,C)的弹性参数计算值则表明YPd3C的硬度大于YPd3B.根据晶体机械稳定标准得到YPd3B和YPd3C的失稳临界压强分别约为16.5 GPa和23 GPa.由Pugh经验关系可知YPd3X(X=B,C)均属于韧性材料,且YPd3B的韧性略高于YPd3C.电子能带结构分析表明YPd3B和YPd3C均具有金属特性,且导电能力相当.由态密度和电荷密度分析得知,X与Pd之间形成较强的共价键,而Y与Pd3X之间形成离子键,化学键键能的不同是两种材料的弹性参数存在差异的内在原因.上述的研究结果为YPd3X(X=B,C)的力电材料的设计和应用提供了一定的理论依据. 相似文献
14.
利用掠入射荧光X射线吸收精细结构(XAFS)方法研究了在400℃的温度下分子束外延生长的Si/Gen/Si(001)异质结薄膜(n=1,2,4和8个原子层)中Ge原子的局域环境结构.结果表明,在1至2个Ge原子层(ML)生长厚度的异质结薄膜中,Ge原子的第一近邻配位主要是Si原子.随着Ge原子层厚度增加到4ML,Ge原子的最近邻配位壳层中的Ge-Ge配位的平均配位数增加到1.3.当Ge原子层厚度增加到8ML时,第一配位壳层中的Ge-Ge配位占的比例只有55%.这表明在400℃的生长条件下,Ge原子有很强的迁移到Si覆盖层的能力.随着Ge层厚度从1 增加到2,4和8ML,Ge原子迁移到Si覆盖层的量由0.5ML分别增加到1.5,2.0和3.0ML.认为在覆盖Si过程中Ge原子的迁移主要是通过产生Ge原子表面偏析来降低表面能和Ge层的应变能.
关键词:
XAFS
n/Si(001)异质膜')" href="#">Si/Gen/Si(001)异质膜
迁移效应 相似文献
15.
A controlled quantum teleportation scheme of an N-particle unknown state via three-particle W1 states
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In this paper a controlled quantum teleportation scheme of an N-particle unknown state is proposed when N groups of three-particle W1 states are utilized as quantum channels. The quantum information of N-particle unknown state is transmitted from the sender to the recipient under the control of all supervisors. It can be realized with a certain probability. After the sender makes Bell-state measurements and the supervisors perform the computational basis measurements, the recipient will introduce auxiliary particles and carry out unitary transformations depending on classical information from the sender and the supervisors. Finally, the computational basis measurement will be performed by the recipient to confirm whether the teleportation succeeds or not. The successful completion of the scheme relies on all supervisors' cooperation. In addition, the fidelity and security of the scheme are discussed. 相似文献
16.
Group-theoretical methods are used to induce “global” distortions of C 60 from basis function(s) of a single “local” distortion in two cases: (1) The 60 vibrational modes arising from radial displacements of carbon atoms are found in terms of basis functions of A′, the one-dimensional symmetric representation of Cs; (2) The 24 vibrational modes arising from tangential displacements of hypothetical atoms placed at pentagon centers are found in terms of basis functions of E 1, the vector irreducible representation of C5v . The induction process is simplified by an icon notation (v) or (vμ) which uniquely labels the operations in Ih if μ,v = 0, 1, 2, 3, 4 and under/over lining of a digit is included. These icons describe the transformations IUSvTSμ of Felix Kline referred to a five-fold z-axis and two-fold x-axis and serve to label and “distinguish” symmetrically equivalent points of the truncated icosahedron. 相似文献
17.
ABSTRACTHydrogen storage reactions on Ni ? C59X(X = B, N) heterofullerene are investigated by using the state-of-the-art density functional theory calculations. The Ni atom prefers to bind at the bridge site between two hexagonal rings, and can bind up to five hydrogen molecules with average adsorption energies of (?0.94, ?0.48, ?0.33, ?0.25 and ?0.20 eV) per hydrogen molecule for Ni ? C59B, while (?1.20, ?0.60, ?0.41, ?0.28 and ?0.23 eV) per hydrogen molecule for Ni ? C59N. With no metal clustering, the system gravimetric capacities are expected to be as large as 10.87 and 10.85 wt % for 5H2NiC59B?and 5H2NiC59N, respectively. While the desorption activation barriers of the complexes 1H2 + C59X?(X = B, N)?are outside the Department of Energy domain (?0.2 to ?0.6 eV), the desorption activation barriers of the complexes nH2 + C59X(X = B, N)(n = 2 ? 5) are inside this domain. The hydrogen storage of the irreversible 1H2 + NiC59X?(X = B, N) and reversible 2H2 + NiC59X?(X = B, N) interactions is characterised in terms of density of states and projected densities of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity and molecular electrostatic potentials. 相似文献
18.
用极限动力学模型研究了C60分子在有序-无序相变和玻璃态相变温度区间取向 角为98°和38°的取向概率与温度的关系.计算结果在玻璃态相变点附近的85K,90K和有序- 无序相变点的260K分别与实验值相吻合,取向概率对实验值更精确的拟合及其对温度的二阶 导数预言玻璃态相变点在84K.导出了弛豫规律,其结果表明:双能级的C60分子从非平衡态到平衡态的弛豫行为与非指数因子β有关,其总的弛豫时间决定于其中一个较 短的弛豫时间,展宽指数形式保持不变.讨论了KWW方程的非
关键词:
60')" href="#">C60
取向概率
非平衡态弛豫 相似文献
19.
The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods
are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12 compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of
one crystal unit with structure having been optimized. The characters of magnetic moments, total density of states (TDOS)
and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that
the total magnetic moments of RFe10Si2 (R = Y, Nd) are larger than those of RFe10
M
2 (M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the magnetic moments of Fe at
three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly
enhanced by the introduction of Si atoms according to spin fluctuation of DOS at Fermi level. 相似文献