Vibrational Spectra and Radiation-Stimulated Change in the Structure of Crystalline Silica

A spectroscopic investigation of a radiation-stimulated change in the structure of a phase transition in a crystalline silica (alpha quartz) exposed to a set of fluences of fast neutrons has been carried out using optical methods (IR reflection spectroscopy, Raman scattering) and x-ray methods. The laws governing the change in the spectral characteristics of some bands as a result of structural transformation of the crystal on exposure to radiation and the change in the parameters of the stretching and deformation vibrations of bridge bonds have been established. It is assumed that irradiation of a crystal leads to two processes of destruction of the Si—O—Si bonds and their deformation, causing a change in the initial structure. The x-ray spectroscopy data for individual parameters were compared to the Raman spectrum for a heated quartz. A conclusion has been drawn concerning the correlation between corresponding dependences and the formation of a state similar to the high-temperature modification of quartz at a certain stage of irradiation with fast neutrons.     

Effect of Neutron Irradiation on the Optical Properties of Corundum

The characteristic features of the process of radiation-defect formation and of a change in the structural and optical properties of corundum crystals exposed to reactor radiation have been investigated by spectroscopic methods. The dose dependences of the generation of a number of color and luminescence centers, the regularities of their thermal and photodecoloration, and the energies of activation of the centers have been determined. The influence of the overlapping of the absorption and luminescence centers has been estimated. The radiation-induced change in the structural parameters of the crystal and in the characteristics of the main reflexes has been determined. It has been established that at large reactor radiation fluxes the processes of damage of the crystal are accelerated and a small halo appears at 12.5°. The possible mechanism of damage and disordering of the structure of corundum irradiated in the reactor with a fairly large flux is discussed.     

GaN直纳米线的光学性能

对 Ga N直纳米线的拉曼光谱及光致发光光谱进行了研究。拉曼光谱表明 ,与计算值相比 ,E2 ( high)声子频率在 560 cm- 1有 -9cm- 1的移动 ,这种声子频率显示出向低能带频移及带变宽的特征 ,是由于纳米尺寸效应所引起的结果。体系的光致发光光谱在 3 44 .8nm附近的近带隙发光 ,与文献报道的 Ga N体材料的数值3 65nm相比有一蓝移 ,这是由于量子限制效应造成的     

石英光学窗口的高温热辐射物性实验研究

建立了高温光谱透射率测量装置,测量了石英光学窗口在300～1100K温度范围内的可见光及近红外四个光谱下的法向透射率。根据样件的光谱透射率测量数据,基于双厚度法计算获得了石英光学窗口的光谱折射率和光谱吸收系数。利用光谱折射率和光谱吸收系数预测的另一种厚度的样片透射率数据与实验测量值的相对误差小于10%。     

纳米二氧化钒薄膜的电学与光学相变特性

采用双离子束溅射氧化钒薄膜附加热处理的方式制备了纳米二氧化钒薄膜。在热驱动方式下,分别利用四探针测试技术和傅里叶变换红外光谱技术对纳米二氧化钒薄膜的电学与光学半导体-金属相变特性进行了测试与分析。实验结果表明,电学相变特性与光学相变特性之间存在明显的偏差,电学相变温度为63 ℃,高于光学相变温度,60 ℃;电学相变持续的温度宽度较光学相变持续温度宽度宽;在红外光波段,随着波长的增加,纳米二氧化钒薄膜的光学相变温度逐渐增大,由半导体相向金属相转变的初始温度逐渐升高,相变持续的温度宽度变窄。在红外光波段,纳米二氧化钒薄膜的光学相变特性可以通过光波波长进行调控,电学相变特性更适合表征纳米VO₂薄膜的半导体-金属相变特性。     

Effect of the Dose of Irradiation by Fast Neutrons on the Optical Properties of Vitreous Silicon Dioxide

The influence of neutron irradiation on some parameters of vitreous silicon dioxide was investigated by optical, dielectric, and x-ray spectroscopy. The laws governing the change in the spectral characteristics, structure parameters, polarizability, and refractive index of vitreous silicon dioxide in a wide range of fluences of fast neutrons are determined. It is assumed that the revealed species of the corresponding dose dependences of some characteristics are caused by the radiation-stimulated change in the structure of the substance. The effect of large doses is considered.     

Influence of the Change in Charges on the Atoms of the CNO2 Fragment of Nitrobenzene Derivatives Caused by Substituents on the Frequency of the Antisymmetric Stretching Vibration of the Nitro Group

The dependence of the frequency of the antisymmetric stretching vibration of the nitro group of the para-derivatives of nitrobenzene on the charges on the atoms of the CNO₂ group calculated by the PM3 method has been investigated. It is shown that a change in the position of the absorption band of the antisymmetric stretching vibration of the nitro group of para-derivatives of nitrobenzene, as well as Hammett's constants _p , can be used as a measure of the electronic effect of substituents, that is, of a change in the charges on the atoms of the nitro group.     

热致晶化高反射率SbOx薄膜的结构分析和光学性质

利用直流磁控反应溅射法制备了SbOx薄膜,利用X射线衍射分析仪和光谱仪分别研究了这种薄膜热致晶化的微观结构和光学性质的变化,并通过非晶态薄膜粉末的示差扫描量热实验测出不同加热速度条件下结晶峰温度,研究了这种薄膜的结晶动力学。发现沉积态SbOx薄膜为非晶态,非晶态SbOx薄膜在热致晶化过程中发生了两种变化,分别对应为较低温度下Sb晶体和较高温度下立方Sb2O3相的生成。退火后晶态薄膜中出现了单质Sb和Sb2O3,300℃退火后Sb2O3相含量最大。晶态薄膜的反射率均高于沉积态,在晶态薄膜中200℃退火的薄膜反射率最大。     

传压介质对晶格振动和相变压力的影响——α-Bi2O3的高压拉曼光谱研究

 本文分别使用4∶1的甲醇-乙醇混合溶液和固态氩做传压介质测量α-Bi₂O₃的高压拉曼光谱。实验结果表明，传压介质对样品的谱线频移速率及相变压力有明显的影响。通过对拉曼光谱的分析认定，α-Bi₂O₃在高压下可能经历了一次结构相变，在准静水压和非静水压条件下的相变压力分别为23.1 GPa和20.4 GPa。     

Fabrication and Gamma-Ray Irradiation Effect on Optical and Mechanical Properties of Germano-Silicate Glass Fibers with Inner Cladding of B and F Doped Silica Glasses

ABSTRACT

The effect of glass composition, pure silica glass, boron-doped and fluorine-doped silica glasses of inner cladding, in the germano-silicate glass core fibers on optical and mechanical properties upon the γ-ray irradiation was investigated. Enhanced radiation hardening at 1,550 nm was found in both the B- and F-doped fibers after the γ-ray irradiation with dose-rate of 1.25 kGy/h. The radiation-induced attenuation (RIA) was found to increase in the order of the B-doped fiber, the F-doped fiber, and the silica fiber. While no major influence on the refractive index of the fibers after the γ-ray irradiation was found, the residual stress was slightly changed.     

生物组织的散射相函数及其二阶光学参量的性质

生物组织是一种复杂介质,在许多情况下仅仅用各向异性因子g来描述其散射特性是不够的。由于二阶参量γ是一个与相函数的二阶矩g2有关,并表示与一阶参量g1关系的量,因此用g和γ两个参量能更好地描述组织的光学性质。对几种目前用于描述人体组织的相函数及其二阶参量作了简要讨论,在此基础上研究了相函数的选取对测量参量γ的影响。研究表明γ是一个可测量的组织参量。研究工作对于建立含有相函数高阶矩的漫散射理论,对如何测量生物组织的高阶参量γ,并能够准确测量其它光学参量具有重要理论意义和实际府用价值。     

Effect of Hydrostatic Pressure on Optical Properties of TlBr and TlCl

We present first principles calculations of optical properties of binary semiconductor compounds TlBr and TlCl.Dependences of dielectric function,reflectivity and refractive index on hydrostatic pressure are calculated using self-consistent scalar relativistic full potential linear augmented plane wave method(FP-LAPW) within a generalized gradient approximation(GGA).They are compared with previous calculations and experimental measurements.Good agreements are found.     

不同稳定剂对水溶性CdTe纳米晶光学性质的影响

分别用巯基乙酸(TGA),巯基丙酸(MPA),L-半胱氨酸(L-Cys),3-巯基-1,2-丙二醇(TG)作为稳定剂,在水相中合成出CdTe纳米晶体,研究了稳定剂对所制备的纳米晶光学性质的影响,并且对所合成的球状和棒状纳米晶的稳定性进行了研究。实验结果表明,不同的稳定剂可以得到不同型貌的纳米晶,用L-半胱氨酸(L-Cys),巯基乙酸(TGA),巯基丙酸(MPA),3-巯基-1,2-丙二醇(TG)所得到的CdTe纳米晶的吸收和发射峰位不同,这是受稳定剂自身的官能团性质和空间位阻作用影响的结果。     

SiO2和HfO2薄膜光学性能的椭偏光谱测量

结合XRD和原子力显微镜等方法,利用椭圆偏振光谱仪测试了单层SiO2薄膜（K9基片）和单层HfO2薄膜（K9基片）的椭偏参数,并用Sellmeier模型和Cauchy模型对两种薄膜进行拟合,获得了SiO2薄膜和HfO2薄膜在300-800nm波段内的色散关系。用X射线衍射仪确定薄膜结构,并用原子力显微镜观察薄膜的微观形貌,分析表明：SiO2薄膜晶相结构呈现无定型结构,HfO2薄膜的晶相结构呈现单斜相结构;薄膜光学常数的大小和薄膜的表面形貌有关;Sellmeier和Cauchy模型较好地描述了该波段内薄膜的光学性能,并得到薄膜的折射率和消光系数等光学常数随波长的变化规律。     

重掺杂AZO透明导电薄膜的光电特性

以Al质量分数为2%的ZnO陶瓷靶为靶材,在氧气气氛中,采用脉冲激光沉积方法(PLD)在石英衬底表面生长了重掺杂的ZnO:Al(AZO)薄膜.通过X射线衍射仪、紫外可见分光光度计、微区拉曼光谱仪、霍尔测量仪对合成薄膜材料的晶体结构、光学、电学性质等进行了研究.结果表明:所制备的AZO薄膜呈现具有高度c轴择优取向的ZnO...     

薄膜厚度对AgInSbTe相变薄膜的光学性质的影响

采用射频溅射法制备了Ag8In14Sb55Te23相变薄膜,对深积态薄膜在300℃时进行了热处理,测量了不同厚度薄膜的反射、吸收谱及光学常数。研究了薄膜的光学常数与薄膜厚度的关系。结果表明在一定的厚度范围其光学常数随膜层厚度的不同有较大的变化,尤其在短波长范围内更为明显,这对于短波长记录相变光盘有重要意义。     

新型噁二唑有机电致发光小分子光电性质研究

通过升降温差热分析(DSC)曲线、偏光显微镜、紫外吸收光谱、电化学行为曲线以及多层器件等,研究了噁二唑衍生物小分子的电学和光学性质,发现其同时具有液晶性、电子和空穴传输性、发光性等优良性能.引进R-OXD(En)层后的多层器件在低于3 V时就能得到可见光发射,在7 V时可以得到光亮度为1000 cdm^-2.此系列小分子可降低有机电致发光器件开启电压,提高发光亮度和发光效率,是一种非常具有吸引力的有机电致发光小分子.     

Influence of Chemical Environment on the Optical Properties in Transition Metal Ions Doped Materials

The sensibility of luminescent properties in transition metal doped materials to the matrices' chemical environment is explained in this paper, this is because of their strong phonon-electron coupling which are caused by the 3d electrons exposed nature. The influence of the chemical environments on the Mn²⁺-doped materials' optical properties, including the structure type of coordinate polyhedron, the polyhedral bridge linking manner and the lattice parameter, was illustrated in detail in this work. The impact of crystal field strength parameter (10 Dq) on the maximum energy differentiae in spontaneous emission band of Cr³⁺:⁴T_2g→⁴A_2g and in excited state absorption band ⁴T_2g→⁴T_1g (⁴F), and covalent bond intension's impact on the optical properties of Os⁴⁺ were also analyzed. This work's purpose is to discover the principle of the sensibility character, then we can use it to optimal the design of materials in order to find the excellent luminescent materials for practical utilization.     

溅射工艺参数对AgInSbTe相变薄膜光学性质的影响

采用射频磁控溅射工艺,在K9玻璃片上用Ag-In-Sb-Te合金靶制备了相变薄膜,对沉积态薄膜在300℃下进行了热处理,测量了薄膜的光学性质。通过改变本底气压,溅射气压及溅射功率,研究了工艺参数对薄膜光学性质的影响,实验表明,本底气压,溅射气压及射功率综合决定了AgInSbTe薄膜的光学性质,对AgInSbTe薄膜的制备,选择较高的本底真空度,适当的溅射气压及溅射功率是非常重要的。     

On the Electrical and Optical Properties of Some Poly(Azomethine Sulfone)s in Thin Films

Poly(azomethine sulfone)s were synthesized by reacting 4,4′-sulfonyl bis(4-chlorophenyl) with 2,2-bis(4-hydroxyphenyl)propane and azomethine bisphenol in different molar ratios. Thin films were deposited from solution onto glass substrates. Study of the temperature dependences of the electrical conductivity, σ, and Seebeck coefficient, S, were performed in the temperature range 300 K–500 K. Thermal activation energies of electrical conduction, E_a , calculated from these dependences, ranged between 1.50 eV and 1.85 eV. The values of E_a were smaller for polymers with extended conjugation systems. The possibility to use the polymers in thermistor technology is discussed. The aspect of the temperature dependences of σ and S shows that a model based on the energy band-gap representation can be successfully used for explaining the electronic transport mechanism in the higher temperature range. In the lower temperature range, the mechanism of the electrical conduction is discussed in terms of the Mott variable range hopping conduction. The values of some optical parameters (absorption coefficient, optical band gap, etc.) were determined from transmission spectra.