Characteristics of Sn-Doped Ge2Sb2Te5 Films Used for Phase-Change Memory

Sn-doped Ge2Sb2Te5 thin films deposited on Si（100）/SiO2 substrates by rf magnetron sputtering are investigated by a differential scanning calorimeter, x-ray diffraction and sheet resistance measurement. The crystallization temperatures of the 3.58 at.%, 6.92 at.% and 10.04 at.% Sn-doped Ge2Sb2Te5 thin films have decreases of 5.3, 6.1 and 0.9℃, respectively, which is beneficial to reduce the switching current for the amorphous-to-crystalline phase transition. Due to Sn-doping, the sheet resistance of crystalline Ge2Sb2Te5 thin films increases about 2-10 times, which may be useful to reduce the switching current for the amorphous-to-crystalline phase change. In addition, an obvious decreasing dispersibility for the sheet resistance of Sn-doped Ge2Sb2Te5 thin films in the crystalline state has been observed, which can play an important role in minimizing resistance difference for the phase-change memory cell element arrays.     

硒铟镓银晶体中二相沉淀物研究

应用金相显微镜、能量色散谱仪、X射线衍射仪等对AgGa0.8In0.2Se2晶体中的二相沉淀物进行了观察、测试和分析,发现呈梭状的二相沉淀物存在明显Ag含量缺失.根据EDS测试结果和差热实验数据研究了消除该二相沉淀物的热处理方案,即在含有Ag2Se组分的AgGa0.8In0.2Se2多晶混合粉末包埋下,对AgGa0.8 In0.2Se2晶体进行淬火处理.结果表明:用含有1.26wt; Ag2Se的同成分多晶混合粉末包埋,在720℃下保温120 h后经淬火处理的晶片,梭状二相沉淀物得到很好的消除,红外透过率得到显著提高.     

用铜电极电解饱和食盐水实验的深度研究

用铜电极电解饱和食盐水,是苏教版《实验化学》教材中专题5的一个拓展实验,该实验选自于刘怀乐老师的《电解饱和食盐水的趣味实验》^[1],实验中用铜丝作阳极,产生了许多有趣的现象。但笔者用教材所给的装置进行实验时,发现不利于有些现象的观察。在对电解产生的沉淀物进行实验探究时,出现的现象与刘老师的叙述并不一样。     

Reconciliation of size–density bivariate distributions over a separating node

Data reconciliation considers the restoration of mass balance among the noise prone measured data by way of component adjustments for the various particle size or particle density classes or assays over the separating node. In this paper, the method of Lagrange multipliers has been extended to balance bivariate feed and product size-density distributions of coal particles split from a settling column. The settling suspension in the column was split into two product fractions at 40% height from the bottom after a minute settling of homogenized suspension at start. Reconciliation of data assists to estimate solid flow split of particles to the settled stream as well as helps to calculate the profiles of partition curves of the marginal particle size or particle density distributions. In general, Lagrange multiplier method with uniform weighting of its components may not guarantee a smooth partition surface and thus the reconciled data needs further refinement to establish the nature of the surface. In order to overcome this difficulty, a simple alternative method of reconciling bivariate size-density data using partition surface concept is explored in this paper.     

锌与硝酸铜溶液反应的实验探究

Zn与Cu(NO3)2溶液发生反应,Zn置换Cu(NO3)2 溶液中的Cu,生成Cu和Zn(NO3)2,这似乎是理所当然的简单反应,但实验的现象却不是想象的那么简单: [实验1] 在一支大试管中注入1/3试管的1 mol/L Cu(NO3)2溶液,插入一块Zn片(高于液面的长度),静置观察,结果发现:①在反应的初期,Zn片上有大量气泡冒出,同时液面的上一层Cu(NO3)2溶液开始呈显绿色,并且逐渐向液面下的深处扩散,试管底部有红色的Cu泥出现.     

沉淀固体微粒的湍流扩散

由于安装在玻璃粉末沉淀床上方的格栅的振动产生湍流运动。在格栅作用下,沉淀的部分玻璃粉末浮动上升,在格栅上方形成深度为D的湍流悬浮层,而其上部为一非湍流的静止的流体层。体积浓度的测量结果表明,在深度方向上仅有较弱的浓度梯度,并且在层外缘浓度迅速减小至零。基于浓度流量模型的理论分析与实验结果符合良好。     

ICP-AES法对硅酸盐测定中LiBO2与样品熔融后玻璃熔珠酸溶解问题的研究

本文研究了应用 ICP- AES法测定硅酸盐元素分析中 L i BO2 与样品熔融后玻璃熔珠的酸溶解中出现沉淀的问题 ,并就其熔珠加热出现的沉淀进行了 X射线能谱元素分析 ,并且讨论了解决出现白色沉淀的方法。     

反射光谱法直接测定沉淀物研究

报道一种新的分析方法－反射光谱法直接测定沉物。探讨了该方法的基本原理，影响因素及测定条件。该方法直接测定沉物快速，简便。应用于污水及土壤样品中微量汞（Ⅱ）的测定，结果满意。     

Comparison of TiO2 and ZrO2 Films Deposited by Electron-Beam Evaporation and by Sol-Gel Process

TiO2 and ZrO2 films are deposited by electron-beam （EB） evaporation and by sol-gel process. The film properties are characterized by visible and Fourier-transform infrared spectrometry, x-ray diffraction analysis, surface roughness measure, absorption and laser-induced damage threshold （LIDT） test. It is found that the sol-gel films have lower refractive index, packing density and roughness than EB deposited films due to their amorphous structure and high OH group concentration in the film. The high LIDT of sol-gel films is mainly due to their amorphous and porous structure, and low absorption. LIDT of EB deposited film is considerably affected by defects in the film, and LIDT of sol-gel deposited film is mainly effected by residual organic impurities and solvent trapped in the film.