日本地球惑星科学連合2014年大会

講演情報

ポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS36_1PO1] 結晶成長における界面・ナノ現象

2014年5月1日(木) 18:15 〜 19:30 3階ポスター会場 (3F)

コンビーナ:*木村 勇気(東北大学)、三浦 均(名古屋市立大学大学院システム自然科学研究科)、塚本 勝男(東北大学大学院理学研究科地学専攻)、佐藤 久夫(三菱マテリアル株式会社エネルギー事業センター那珂エネルギー開発研究所)

18:15 〜 19:30

[MIS36-P01] ガス中蒸発法におけるナノ粒子生成過程の高速偏光“その場”観察

*木村 勇気1三原 新2大沼 隼志2石塚 紳之介1村山 健太1塚本 勝男1 (1.東北大学大学院理学研究科地学専攻、2.株式会社フォトロン)

キーワード:核生成, 偏光高速カメラ, その場観察

The gas evaporation method has been investigated for more than half a century since the Kubo effect was reported (1962). There have been many studies on the produced nanoparticles mainly using a transmission electron microscope, which have elucidated the different physical properties of nanoparticles from those in bulk. On the other hand, there have been almost no reports on nucleation in smoke related to crystal growth. Recently, we achieved in-situ observation of the nucleation process in smoke using a double-wavelength Mach-Zehnder-type interferometer, which can determine the temperature and pressure at the nucleation simultaneously. A series of experiments clearly showed that smoke particles condense homogeneously only in a very high supersaturated environment [1-3]. In a preliminary experiment using tungsten trioxide, the smoke particles condensed with a degree of supersaturation as high as 〜106. In this process, since evaporant is continuously supplied into the surrounding of the evaporation source, the flow of smoke after the nucleation and growth of nanoparticles has been simply considered as a consecutive process. The nucleation and growth of smoke particles should be a rapid process (ms order) due to high supersaturation, so the concentration of the evaporated vapor drastically decreases. However, the details of the formation process remain unknown.
In this study, we attempted to visualize the nucleation of nanoparticles and motion of smoke using a high-speed polarization image sensor (Photron Inc.) to clarify the details of the nucleation process of smoke particles. Since the sensor itself has pixels with micro-polarizers, a phase shift interferogram can be obtained in less than a millisecond because of the lack of mechanical movement free, and can therefore be applied to rapid phenomena such as nucleation in vapor phase. Here, we show the preliminary results of homogeneous nucleation of tungsten oxide from vapor phase.

[1] Y. Kimura, H. Miura, K. Tsukamoto, C. Li, T. Maki, Interferometric in-situ observation during nucleation and growth of WO3 nanocrystals in vapor phase, Journal of Crystal Growth, 316 (2011) 196-200.
[2] Y. Kimura, K. Tsukamoto, Interferometric observation of temperature distributions in the smoke experiment, J. Jpn. Soc. Microgravity Appl., 28 (2011) S9-S12.
[3] Y. Kimura, K. K. Tanaka, H. Miura, K. Tsukamoto, Direct observation of the homogeneous nucleation of manganese in the vapor phase and determination of surface free energy and sticking coefficient, Crystal Growth & Design, 12 (2012) 3278?3284.