高分辨电子显微像的定量分析与应用II.InGaAs/GaAs应变层超晶格的高分辨像定量分析  

Researches in Ultra rapid Freezing without Cryoprotective Agents for Rat Heart Muscular Tissue

作　　者：兰建章[1] 王绍青[1] 孟祥敏[1] 于瀛大[1] 谢天生[1] 李斗星[1] 

机构地区：[1]中国科学院金属研究所固体原子像开放实验室

出　　处：《电子显微学报》1998年第2期176-181,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金;国家高技术新材料领域专家委员会资助

摘　　要：使用高分辨像定量分析方法和像模拟技术，对外延生长的ＧａＡｓ／ＩｎｘＧａ１－ｘＡｓ应变层超晶格的微观组态进行了详细的分析。用像模拟验证了成像位置与结构投影的对应关系。使用像点定位及畸变测量的分析方法，获得了晶格畸变位移分布图及畸变沿生长方向的分布曲线，扣除由四方畸变导致的点阵膨胀与收缩，得到了仅由Ｉｎ元素分布导致的点阵参数变化曲线。由晶格参数与Ｉｎ元素含量的线性对应关系，获得了超晶格中Ｉｎ元素沿生长方向的分布曲线。Ultra rapid freezing is an established preparative technique in immuno cytochemical investigation, X ray microanalysis and ultrastructure study. However, it is important to avoid ice crystal damages in biological tissues during rapid freezing. It has been shown theoretically that the ideal cooling rate should be greater than 10,000K/s during rapid freezing. In practice, it is not easy to obtain this ideal cooling rate due to the high heat capacity and low thermal conductivity of biological specimens. This means that depth of well preserved superficial layers (vitrification) are only about 20 or 30μm in the frozen biological samples. We have frozen the rat heart muscular tissues by the freezing method of without any cryoprotective agents. The results show that the intact structures have been obtained in the area of the frozen tissue surface to 15—20μm depth. The muscular fibers are regular and A bands, I bands and Z line are clearly funded. The glycogen particles are well reserved. Analysis shows that deeper than the surface 20μm,ice crystals increase in the area. The muscular tissue had been nearly replaced by ice crystals over 30μm depth. After the composition of specimens frozen were analysed by the EDAX 9100/60 energy dispersive analysis system, we found that there are more potassium in intact structure of heart muscular tissue frozen.

关 键 词：电子显微镜 应变层超晶格 外延生长 半导体材料 

分 类 号：TN304.054[电子电信—物理电子学]