Ge-Sb-Se硫系薄膜制备及光学特性研究

介绍了几种常见的硫系薄膜制备方法, 根据现有实验条件采用热蒸发法和磁控溅射法制备出Ge-Sb-Se三元体系硫系薄膜, 通过台阶仪测试薄膜的厚度和表面粗糙度, 计算出两种制备方法的成膜速率, 并通过X射线光电子能谱测试了两种制备方法所得薄膜与块体靶材组分的差别. 利用Z扫描技术和分光光度计测试了热蒸发法制备所得薄膜的三阶非线性性能和透过光谱, 计算出非线性折射率、非线性吸收系数和薄膜厚度等参数. 结果表明热蒸发法制备Ge-Sb-Se薄膜具有良好的物理结构和光学特性, 在集成光学器件方面很高的应用潜力.     

Calculation of cohesive energy of actinide metals

According to empirical electron theory of solids and molecules (EET), an equation for calculating the cohesive energy of actinide metals is given, the cohesive energy of 9 actinide metals with known crystal structure is calculated, which is identical with the experimental values on the whole, and the cohesive energy of 6 actinide metals with unknown crystal structure is forecast.     

Structural interpretation of specific heat measurements on glassy Se100− x Sb x alloys

Differential scanning calorimetry was used to study glassy Se_{100- x} Sb _x (x = 2, 4, 6, 8 and 10) alloys at a heating rate of 10°C min^?1 under non-isothermal conditions. An extremely large increase in the specific heat, C_p , was observed at the glass-transition temperature. It was also found that the values of C_p below and above the glass-transition temperature, C_pg and C_pe , respectively, are highly composition dependent. This indicates that the Sb additive used in the present study influences the structure of the a-Se. The variation of C_p reveals local extrema in the Se–Sb glassy system at x = 4 and x = 8. The composition dependence of both C_pe and C_pg is explained in terms of the atomic structure.     

金属硫族化合物CsSb2(Se2)0.5Se3的溶剂热合成及其晶体结构分析

以有机溶剂热生长技术(Solvothermal Technique)在180 ℃乙二胺(en)溶液中以SbCl₃与碱金属硒化物Cs₂Se和Se在密闭容器中反应7 d,制备出新的金属硫族化合物CsSb₂(Se₂)_0.5Se₃。以单晶X射线衍射技术测得晶体结构属三斜晶系,空间群为P1,晶胞参数：a=0.653 0(2) nm,b=0.707 1(3) nm,c=0.979 9(4) nm,α=80.37(3)°,β=86.28(3)°,γ=74.61(3)°,V=0.430 0(3) nm³,Z=2。     

Si1Sb2Te3 phase change material for chalcogenide random access memory

This paper investigated phase change Si1Sb2Te3 material for application of chalcogenide random access memory. Current-voltage performance was conducted to determine threshold current of phase change from amorphous phase to polycrystalline phase. The film holds a threshold current about 0.155 mA, which is smaller than the value 0.31 mA of Ge2Sb2Te5 film. Amorphous Si1Sb2Te3 changes to face-centred-cubic structure at ~ 180℃ and changes to hexagonal structure at ~ 270℃. Annealing temperature dependent electric resistivity of Si1Sb2Te3 film was studied by four-point probe method. Data retention of the films was characterized as well.     

Light-induced LC director freezing on a chalcogenide surface

First observations of permanent light-induced director patterning in a transparent liquid crystal (LC) are reported. The patterning was observed in an LC cell with one of the substrates covered with a chalcogenide film. Concentric director ring pattern appears following the irradiation of the chalcogenide surface through the LC layer by a Gaussian beam. The experimental results are explained in terms of the heat transfer from the chalcogenide film to the LC after the light absorption by the chalcogenide film. Heating the LC changes its birefringence according to the spatial intensity distribution of the Gaussian beam. This in turn leads to the spatially oscillating changes of the polarisation state of light in the plane of the chalcogenide film. The oscillating changes of the light polarisation result in producing the light-induced easy orientation axis and the oscillating changes of the anchoring energy. It causes the spatial modulation of the director on the chalcogenide surface and the formation of the concentric ring twist structures in the cell.     

The valence problem of Pd4Br4Te3

Pd(4)Br(4)Te(3) was prepared from Pd, Te, and PdBr(2) at 700 K. Its structure was determined by single-crystal X-ray diffraction to be triclinic, P$\bar 1$, Pearson symbol aP22; a=842.5(2), b=845.0(3), c=864.8(3) pm; alpha=82.55(3), beta=73.36(2), gamma=88.80(2) degrees ; Z=2. The Br and Te atoms are arranged according to the motif of cubic closest-packed spheres in which every 15th position is vacant; the Pd atoms occupy 8/15 of the octahedral voids. The symmetry relations with the packing of spheres are derived. Prominent structural units are hollow cuboctahedral [(PdBrTe)(6)] units, the Pd atoms are positioned near the centers of the square faces of the Br(6)Te(6) cuboctahedra; the cuboctahedra and double-octahedral Pd(2)Br(4)Te(6) units are connected to strands by sharing triangular Te(3) faces. The strands are condensed by common Br atoms into layered assemblies. Conspicuously close Te--Te contacts in the Te(3) triangles indicate attractive Te--Te interactions. The valence puzzle is resolved by the formula Pd(+II)(4)Br(-I)(4)Te(-4/3)(3). Positive Te--Te Mulliken orbital populations and the Pd--K, Br--K, and Te--L(III) XANES spectra of Pd(4)Br(4)Te(3) referenced to the spectra of PdBr(2), K(2)PdBr(6), PdTe, and PdTe(2) are in accord with attractive Te--Te interactions. The measured semiconducting and diamagnetic properties are compatible with the derived picture of chemical bonding in Pd(4)Br(4)Te(3).     

X-Ray Fluorescence Determination of the Composition of Chalcogenide Glasses

A procedure of x-ray spectroscopic fluorescence determination of the composition of chalcogenide glasses As _x S_100–x is developed, and its metrological characteristics are established. The magnitude of relative standard deviation in determining the content of the components does not exceed 0.003, and the results of x-ray spectroscopic fluorescence analysis (RSFA) agree well with the data of a gravimetric method.     

新型单模大模场红外硫系玻璃光子晶体光纤设计研究

大模场光子晶体光纤在高功率激光传输、光纤放大器、光纤激光器中的广泛应用, 使其受到研究者的广泛关注.硫系玻璃在红外波段(1–20μm)具有优良透过性能, 且具有折射率高(2.0–3.5)、声子能量低(小于350 cm^-1)、 组分可调等特性, 成为制备红外光纤的理想材料. 本文设计一种基于Ge₂₀Sb₁₅Se₆₅硫系玻璃基质的新型单模传输、低损耗、超大模场面积光子晶体光纤结构, 经理论验证其在λ =10.6 μm处基模限制损耗远低于0.1 dB/m, 高阶限制模损耗大于2 dB/m, 模场面积约为13333 μm². 关键词： 硫系玻璃 大模场面积 红外光子晶体光纤 结构设计     

Solid State Synthesis and Crystal Structure of K3SI

1 INTRODUCTION The alkali metal chalcogenide halides have at- tracted considerable interests since last decades due to their abundant interesting structures and good properties with potential applications[1~8]. The type of M3QX (M = alkali metal, Q = chalcogenide; X = halide) compounds has been well studied. The known structure types of these compounds are only ternary alkali metal oxide halides and can be classified as the following species: 1) cubic anti-perovskite type, such as K3O…