Development of ultrahigh vacuum (UHV) transmission electron microscope for in-situ observation of ice

2015 Fiscal Year Final Research Report

• Project/Area Number: 25247086
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Hokkaido University
• Principal Investigator: Kouchi Akira 北海道大学, 低温科学研究所, 教授 (60161866)
• Co-Investigator(Kenkyū-buntansha): HIDAKA Hiroshi 北海道大学, 低温科学研究所, 助教 (00400010) ; OBA Yasuhiro 北海道大学, 低温科学研究所, 助教 (00507535) ; HAMA Tetsuya 北海道大学, 低温科学研究所, 助教 (20579172) ; CHIGAI Takeshi 北海道大学, 低温科学研究所, 技術専門職員 (60601309)
• Co-Investigator(Renkei-kenkyūsha): WATANABE Naoki 北海道大学, 低温科学研究所, 教授 (50271531) ; KIMURA Yuki 北海道大学, 低温科学研究所, 准教授 (50449542) ; TOMARU Takayuki 大学共同利用機関法人高エネルギー加速器研究機構, 超伝導低温工学センター, 准教授 (80391712)
• Project Period (FY): 2013-10-21 – 2016-03-31
• Keywords: 超高真空極低温透過型電子顕微鏡 / アモルファス氷 / 氷結晶 / 紫外線照射 / 氷XI / マトリックス昇華法 / 高密度アモルファス氷

Outline of Final Research Achievements

An ultrahigh vacuum (UHV) transmission electron microscope for in-situ observation of ice has been developed. We use a single tilt liquid He cooling holder for specimen cooling to 4 K. Two ports are directed to the specimen surface for in-situ studies: gas-inlet, and UV irradiation.
Results of preliminary observation are as follows: (1) Macroscopic defect structure of vapor-deposited amorphous ice are observed at first time. (2) Formation of ice XI by UV irradiation onto ices Ih and Ic are observed at 75-100 K. On the other hand, no structural change has been observed by UV irradiation onto amorphous ice. (3) Formation of high-density amorphous ice by CO matrix sublimation method has been developed.

Free Research Field

地球惑星物質科学