CoxR1-xAl2O4(R=Zn,Mg)钴蓝颜料反射性能的研究

采用化学共沉淀法成功地制备出适用于彩电显象管内荧光体着色的Ｃｏ_ｘＲ_１－ｘＡｌ_２Ｏ_４（Ｒ＝Ｚｎ、 Ｍｇ, ｘ＝０．８～１．０）钴蓝颜料： ４５０ｎｍ波长处反射率最大提高１８．２％, ６００ｎｍ处反射率最大降低５％。通过对该颜料反射率的影响因素,如掺杂离子类型、掺杂浓度和Ｃｏ^２＋离子浓度的探讨,结论如下：Ｚｎ^２＋、Ｍｇ^２＋改变钴蓝颜料反射性能的作用机理为晶格畸变引起Ｃｏ^２＋３ｄ轨道电子能级分裂程度的变化;对于掺杂离子Ｚｎ^２＋、Ｍｇ^２＋,ｘ下限值分别约为０．８５和０．８．     

LiNiO2热分解反应动力学研究

用ＤＴＡ和ＸＲＤ研究了ＬｉＮｉＯ_２在空气中的热分解过程为：ＬｉＮｉＯ_２（ｓ）→(６５０～７２０℃)Ｌｉ_２Ｎｉ_８Ｏ_{１０（ｓ）}＋４Ｌｉ_２Ｏ_（ｓ）＋Ｏ_２（ｇ）→(８５０～９５０℃)Ｌｉ_２Ｏ_（ｓ）＋８ＮｉＯ_（ｓ）＋１／２Ｏ_２（ｇ） →(１０００～１１５０℃)ＮｉＯ（ｓ）＋Ｌｉ_２Ｏ_（ｇ）用 Ｄｏｙｌｅ－Ｏｚａｗａ法和 Ｋｉｓｓｉｎｇｅｒ法计算了各反应阶段的表观活化能分别为 ７４７．１８±１．０ ｋＪ·ｍｏｌ^－１、９３２．４６±１．０ ｋＪ·ｍｏｌ^－１和 １１２６．９７±１．０ ｋＪ·ｍｏｌ^－１．用 Ｋｉｓｓｉｎｇｅｒ法确定了反应级数和频率因子,确定了三个阶段的动力学方程分别为 ｄα／ｄt＝１．７３６ｘ１０３９ｅ^{－９００００／Ｔ}（１－α）^{１．０５７}; ｄα／ｄｔ＝１８０６×１０^３９ｅ^{－１１１５００／Ｔ}（１－α）^{０．８４４};ｄα／ｄｔ＝４．２６２×１０４２ｅ^{－１３５０００／Ｔ}（１－α）^{１．２７５}     

新型复合钙钛矿Ba(SbⅢ,SbⅤ)O3的水热合成和表征

采用水热晶化法制备了Ｂａ（Ｓｂ^Ⅲ,Ｓｂ^Ⅴ）Ｏ_３新型钙钛矿型氧化物,并通过ＸＲＤ、 ＩＲ、ＳＥＭ和ＩＣＰ等方法对产物物相、形貌和组成等进行了表征．结果表明,产物为立方钙钛矿结构,晶胞参数为α＝０．４１５ｎｍ,粒度为１～２μｍ具有一定团聚的多晶粉末．产物中锑为三价和五价两种价态．水热条件对合成影响的研究结果表明, Ｂａ（Ｓｂ^Ⅲ,ｓｂ^Ⅴ）Ｏ_３合成的适宜碱度和ｎ_{Ｓｂ（Ⅴ)}／ｎ_{Ｓｂ（Ⅲ）}分别为 ８～１０Ｍｏｌ／Ｌ ＫＯＨ和 ０～１     

复合添加(Ca,Mg)-α-Sialon的晶胞参数研究

利用高分辨率的Ｇｕｉｎｉｅｒ－Ｈａｇｇ相机和计算机控制的底片扫描及数据处理程序系统,测定了复合添加,组份为（Ｃａ_０．５Ｍｇ_０．５）_xＳｉ_{１２－３ｘ}Al_3xＯ_ｘＮ１_６－ｘ（ｘ＝０．３、０．６、１．０和１．４）的α－Ｓｏａｌｏｎ的晶胞参数．材料由热压工艺制备而得．研究结果表明,当ｘ≥１．０时,材料的主晶相为α－Ｓｉａｌｏｎ和含Ｍｇ的ＡlＮ多型体．（Ｃａ,Ｍｇ）－α－Ｓｉａｌｏｎ的晶胞参数明显低于相同组份下的Ｃａ－α－Ｓｉａｌｏｎ的晶胞参数·ＥＤＡＸ的结果进一步给出固溶进入α－Ｓｉａｌｏｎ的包括名义组份中９０％的Ｃａ^＋＋和少量的Ｍｇ^＋＋,而大部分Ｍｇ^＋＋进入ＡlＮ多型体,这一结果为净化α－Ｓｉａｌｏｎ陶瓷的晶界提供了新的有效途径．     

介质(Ag/AgI)镀层空芯玻璃光纤的制备及红外传输性能的研究

介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤是一种较好的传输红外激光的柔性光纤材料．采用液相化学沉积法成功地制备了内径分别为１．０、０．５３、０．３２ｍｍ,长度为１．５ｍ的介质（Ａｇ／ＡｇＩ）镀层玻璃空芯光纤．利用傅里叶红外光谱仪和 ＬＪＬ－３５Ａ ＣＯ_２激光器分别测试了介质（Ａｇ／ＡｇＩ）镀层玻璃空芯光纤的传输损耗,测试结果表明：介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤在２．５～２０μｍ波长范围内有较低的损耗值;随着光纤内径（α）的增大,空芯光纤的传输损耗（α）降低,这与Ｍｉｇａｇｉ理论（α　∝１／α^３）相符合．另外,由于光纤的注入端头发热致使介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤的传输损耗随注入功率的增加而增大．     

含钛多孔粘土材料的合成与表征

采用ｓｏｌ－ｇｅｌ法合成了含Ｔｉ多孔粘土材料,并利用ＸＲＤ、ＩＲ、ＤＴＡ等方法对其实验条件进行初步探讨．结果表明,ｓｏｌ－ｇｅｌ法比ＴｉＣｌ_４水解法更容易形成大孔结构,在［Ｔｉ］＝０．８２ｍｏｌ·Ｌ^－１、［Ｔｉ］／±＝２０ｍｍｏｌ·ｇ^－１的条件下,可得到层间开孔达２．９３ｕｍ、比表面３５１．０ｍ~２·ｇ^－１的含Ｔｉ多孔粘土材料,材料在８６０℃之前具有较好的热稳定性．     

纳米粉ZnO的制备及低温热容研究

采用液相沉淀新方法制备了ＺｎＯ纳米晶超微粉末,ＸＲＤ和ＴＥＭ分析结果表明,平均粒径为１８ｎｍ,纤锌矿晶相结构,粒径分布范围较窄．化学分析和ＩＣＰ联合测定,其纯度＞９９．９％．在７８～３７０Ｋ温区,用高精密全自动量热仪测定了热容,拟合出热容随温度变化的多项式方程： Ｃ_ｐ＝ ４０．０４２＋ ２４．５５４Ｘ＋ ０．９３０３３Ｘ^２＋ ２．１６４９Ｘ^３一 １．８３８９Ｘ^４;并与粗晶 ＺｎＯ热容文献值进行比较,从能量的角度分析了各热容曲线不同的原因．     

异相型AgX光色玻璃的聚类分析研究

本文运用聚类分析方法,用Ｆｏｘｐｒｏ２．６编制光功能玻璃数据库及处理程序,对异相型ＡｇＸ光色玻璃进行了聚合分类,并讨论了组成和温度对Ｔ_ｏ、Ｔ_ｄ和忧的影响．结果表明：根据不同样本的Ｔ_ｏ２５、Ｔ_ｄ２５、Ｔ_ｆ２５的相似程度,将异相型ＡｇＸ光色玻璃分成七个相互独立的类别．经过对七类光色玻璃分析认为;Ａｇ、Ｃｕ等元素对光色性质产生较大的影响,而Ｍｎ、Ｎｉ等发色元素则大大降低了玻璃的透过率．分析结果还表明：与在２５下相比较,在４０时的Ｔ_ｏ几乎没有变化,而Ｔ_ｄ、Ｔ_ｆ显著增加．     

铋掺杂铌镁酸铅陶瓷的制备及其有序现象研究

采用二步固相合成法制备钙钛矿相的掺铋铌镁酸铅陶瓷,利用ＸＲＤ和ＴＥＭ选区电子衍射技术对Ｂ位离子非计量有序排列结构进行了表征．研究表明,当为施主掺杂而提高Ｍｇ^２＋、Ｎｂ^５＋离子比例时,铌酸镁前驱体中逐渐出现六方Ｍｇ_４Ｎｂ_９Ｏ_６相．施主Ｂｉ^３＋离子能够有效促进有序微区长大,提高系统有序度．利用Ｘ射线衍射线宽法对ＸＲＤ慢扫描谱进行处理,求得当掺入５％Ｂｉ^３＋离子时,有序微区平均尺寸由纯ＰＭＮ的５nｍ提高到２２ｎｍ．     

R型六方铁氧体化学键性质和穆斯堡尔谱位移研究

利用电介质的平均能带模型计算了Ｒ型六方铁氧体ＢａＴｉ_２Ｆｅ_４Ｏ_１１和ＢａＳｎ_２Ｆｅ_４Ｏ_１１的化学键参数,得到ＢａＴｉ_２Ｆｅ_４Ｏ_１１的２a、４ｆ、４ｅ、６ｇ各晶位平均共价性分别为０．０６２、０．３５４、 ０．３０９、 ０．３６１; ＢａＳｎ_２Ｆｅ_４Ｏ_１１的相应晶位平均共价性分别为０．０６２、 ０．３５３、 ０．１８３、０．２５５．应用化学环境因子计算了^５７Ｆｅ、^１１９Ｓｎ在Ｒ结构中的穆斯堡尔同质异能位移。确定了^５７Ｆｅ,^１１９Ｓｎ的价态和占位情况．     

Photochromic coating by vacuum deposition

Photochronic thin films have been obtained by the simultaneous deposition of silicon monoxide, lead silicate, aluminum chloride and copper-sensitized silver halide, followed by a heat treatment in the dark and in air at 100°–200°C for several hours.

The growth of silver halide microcrystals in the film is explained by a simple diffusion-limited process. The fading process can be described by a second order chemical reaction, which has been applied to a type of photochromic glass containing silver halide microcrystals in the glass matrix. The half-fading and half-darkening time of typical films were 10–20 min and 5–20 min, respectively.     

Reconstruction dynamics of recorded holograms in photochromic glass

We have investigated the dynamics of the record-erase process of holograms in photochromic glass using continuum Nd:YVO? laser radiation (λ=532 nm). A bidimensional microgrid pattern was formed and visualized in photochromic glass, and its diffraction efficiency decay versus time (during reconstruction step) gave us information (D, Δn) about the diffusion process inside the material. The recording and reconstruction processes were carried out in an off-axis setup, and the images of the reconstructed object were recorded by a CCD camera. Measurements realized on reconstructed object images using holograms recorded at a different incident power laser have shown a two-stage process involved in silver atom kinetics.     

Silver halide-containing photochromic powders of SiO2 sol–gel glass

In order to develop a photochromic powder, an SiO2-gel based on tetraethoxysilane (TEOS) was doped with AgNO3 or AgNO2. The dried gel pieces were pulverized and treated with aqueous or ethanolic halide solutions for growing silver halide microcrystals. Both the introduction of cuprous compounds such as CuBr, CuCl, Cu2O, Cu(CH3COO)2·H2O or sulphur-containing compounds and the formation of AgBrxCl1-x crystals lead to variations of photochromic properties. X-ray diffraction measurements indicate that the average diameters of silver halide microcrystals are limited to 70–110nm. Ultraviolet–visible spectroscopic investigations show the reversibility of the darkening/fading process. Cu+-containing samples exhibit a remarkable fading even at room temperature.     

Two-state model of light induced activation and thermal bleaching of photochromic glasses: theory and experiments

The behavior of photochromic glasses during activation and bleaching is investigated. A two-state phenomenological model describing light-induced activation (darkening) and thermal bleaching is presented. The proposed model is based on first-order kinetics. We demonstrate that the time behavior in the activation process (acting simultaneously with the thermal fading) can be characterized by two relaxation times that depend on the intensity of the activating light. These characteristic times are lower than the decay times of the pure thermal bleaching process. We study the temporal evolution of the glass optical density and its dependence on the activating intensity. We also present a series of activation and bleaching experiments that validate the proposed model. Our approach may be used to gain more insight into the transmittance behavior of photosensitive glasses, which could be potentially relevant in a broad range of applications, e.g., real-time holography and reconfigurable optical memories.     

Electron microscopy and optical properties of small gold and silver particles in glass

Transmission electron micrographs of small gold and silver particles grown in glass show uniform particle size in a particular sample. The silhouettes of the particles are those expected for pure particles of f c c metals. From the particle sizes measured from the micrographs and the kinetics of particle growth, the diffusion coefficient of gold in the glass is calculated. This calculation allows particle sizes early in the growth process to be estimated. The optical absorption spectrum for particles containing about 100 atoms is shown.     

Sol-Gel法制备含银二氧化硅纳米薄膜

用sol-gel法在浮法玻璃表面制备了含银二氧化硅薄膜。用TEM和HEED测定了纳米薄膜的微结构。用光谱仪、高阻计和光纤传感器等分别测定了样品的透光率、电阻率和气敏性。     

Effect of Ag addition on crystallization in As2Se3 glasses

Differential scanning calorimetry (DSC) behaviours of glassy As₂Se₃ containing Ag up to 5 at % were measured at various heating rates. The effect of addition of Ag on crystallization of glassy As₂Se₃ was investigated. The glass transition temperature decreased with increasing Ag content. Crystallization kinetics were analysed on the basis of the two-step process model, where crystal growth takes place after nucleation. For non-doped As₂Se₃ two-dimensional growth of crystal was predominant, while for Ag-doped ones three-dimensional growth was very likely. It was supposed for all glassy Ag-doped samples that crystal nuclei exist, though micro-crystallites were not observed on X-ray diffraction traces. The activation energy for crystallization and the glass-forming tendency decreased by the addition of Ag.