Research on behavior of lattice imperfection and phase transformation at low temperature by atom resolution analytical electron microscope

原子分辨率分析电子显微镜研究低温晶格缺陷和相变行为

• 批准号: 63460061
• 负责人: HASHIMOTO Hatsujiro
• 金额: $ 3.84万
• 依托单位: Okayama University of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63460061/
• 关键词: phase transformation; Zeolite radiation damage; electron energy loss spectroscopy; observation of atomic movement in crystals; high Tc superconductor; Atomic level electron microscopy; Charge Density Waves (CDW) phase transformation; Shape memory a

The present research aimed to study the structure change of various materials in atomic scale at various temperature including very low temperature by using atom resolution electron microscopes with the accelerating voltage of 2OOkV, 4OOkV, 8OOkV, which have low temperature specimen stages of liquid helium and liquid nitrogen temperature and an electron energy loss spectrometer. The images were recorded by using GATAN TV camera and Sony TV monitor as well as photographic method.The following observations have been carried out.1. Observation of the atomic structure of Nb_3Sn superconductor at liq.-He and room temperature. Similar observations are carried out for the ceramic super conducting materials with high critical temperature Tc i.e. Y.Ba_2Cu_3O_x, ErBa_2Cu_3O_x, Bi_2Sr_2CaCu_2O_x(85K), and Bi_2Ca_2Cu_3O_x(110K).2. Long chain molecules containing heavy atom Th were supported on graphite thin films and observed in the 2OOkV electron microscope with superconducting objective lens, wh … More ich lower the specimen temperature to be at liq.-He temperature. It was observed that even at the liq.-He temperature, bright spots images of Th atoms in the dark field still moved under the irradiation of 2OOkV electrons.3.1T-TaS_2 and In_xNb_3 Te_4 (X=1.3-1.5) which produce the periodic lattice distortion due to Charge Density Wave were observed at room and liq.-He temperature by 2OOkV electron microscope and their phase transformation were observed in electron diffraction patterns and electron micrographs.4. Radiation damage effect of Zeolite crystal, which shows heavy damage at low temperature was studied at room and low temperatures by an 2OOkV electron microscope with electron energy analyzer. It was noted that even the specimen crystal changes to amorphous, water in crystal are still in the specimen and disappear together with Ca-atoms some minutes later. This phenomena was interpreted by the escape of water and Ca ions in channels of zeolite structure at the same time.5. In order to investigate displacement of atoms and radiation effect under high energy electron irradiation, lMeV Atom Resolution Electron Microscope in California University and 4OOkV one in Okayama were used to see the behavior of Si and Th atoms in crystals and molecules respectively.6. Atomic arrangements and defects structure of Ni Ti shape memory alloy at above and below of the phase transformation temperature were studied by a specimen heating device. The atomic structure of the boundary of two phases and the structure change of repeating twins in every cycle of elevation of the temperature are observed. Less

本研究旨在利用具有液氦和液氮温度低温样品台的200 kV、400 kV、800 kV加速电压的原子分辨电子显微镜和电子能量损失谱仪，在原子尺度上研究各种材料在不同温度（包括极低温）下的结构变化。用GATAN电视摄像机和Sony电视监视器以及照相法记录图像，进行了以下观察.液态Nb_3Sn超导体原子结构的观测他和室温。对具有高临界温度Tc的陶瓷超导材料Y.Ba_2Cu_3O_x、ErBa_2Cu_3O_x、Bi_2Sr_2CaCu_2O_x（85 K）和Bi_2Ca_2Cu_3O_x（110 K）进行了类似的观察.将含重原子Th的长链分子负载在石墨薄膜上，用200 kV超导电子显微镜观察，发现在200 kV超导电子显微镜下观察到的重原子Th分子，在200 kV超导电子显微镜下观察到的重原子Th分子。 ...更多信息 其将试样温度降低到液态。他的体温。据观察，即使在liq.在室温和液态下观察到了由于电荷密度波而产生周期性晶格畸变的3. 1 T-TaS_2和In_xNb_3Te_4（X=1.3-1.5）。用200 kV电子显微镜观察了它们的He温度，用电子衍射谱和电子显微镜观察了它们的相变.利用200 kV电子显微镜和电子能量分析仪，研究了低温下损伤严重的沸石晶体的辐射损伤效应。实验结果表明，即使试样晶体转变为无定形，晶体中的水仍然存在于试样中，并在几分钟后与Ca原子一起消失。这一现象可以用沸石孔道中的水和钙离子同时逃逸来解释.为了研究高能电子辐照下原子的位移和辐射效应，分别用加州大学的1 MeV和冈山的400 kV原子分辨电子显微镜观察了Si和Th原子在晶体和分子中的行为.利用试样加热装置研究了Ni-Ti形状记忆合金在相变温度以上和以下的原子排列和缺陷结构。观察了两相边界的原子结构和重复孪晶在每次升温循环中的结构变化。少

项目成果

Y.Yokota,H.Hashimoto: "Eletron Radiation Damage of Natural Zeolites at Room and Low Temperature" Electron Microscopy(Proc.12th Int. Cong.for Microsc.)(submitted). 4. (1990)

Y.Yokota，H.Hashimoto：“室温和低温下天然沸石的电子辐射损伤”电子显微镜（Proc.12th Int. Cong.for Microsc.）（已提交）。

H.Hashimoto et al.: "Atomic structure of Ion Milled Surface of Si(001)and(111)Observed by a High Resolution Electron Microscope" Proc.3rd.Beijing Conf.and Exhib.on Instrum.Analysis. 3. 93-94 (1989)

H.Hashimoto 等人：“用高分辨率电子显微镜观察到的 Si(001) 和 (111) 离子铣削表面的原子结构”Proc.3rd.Beijing Conf.and Exhib.on Instrum.Analysis。

H.Yoshida,Y.Yokota,H.Hashimoto: "High Resolution Lattice Image of High Tc Superconductors observed at 4.2 K" EMAG-MICRO 89,Inst.Phys.Conf.Ser.#98. 98. 13-15 (1989)

H.Yoshida、Y.Yokota、H.Hashimoto：“在 4.2 K 下观察到的高温超导体的高分辨率晶格图像” EMAG-MICRO 89，Inst.Phys.Conf.Ser。

H.Hashimoto: "Visualization of Small Displacement of Atoms in Crystals by the Processing of Atom Resolution Images." Electron Microscopy(Proceeding of Electron Microscpy America 46th). 46. 12-13 (1988)

H.Hashimoto：“通过处理原子分辨率图像实现晶体中原子小位移的可视化。”

Y.Li,H.Hashimoto et al.: "High Resolution TEM Observation of Shape Memory.Alloy Ni-Ti at Room Temperature to High Temperature" Electron Microscopy (Proc.12th Int.Cong.for Elec.Microsc.)(submitted). 4. (1990)

Y.Li,H.Hashimoto等人：“形状记忆的高分辨率TEM观察。合金Ni-Ti在室温到高温下”电子显微镜（Proc.12th Int.Cong.for Elec.Microsc.）（已提交）