Simultaneous Determination of Surface Free Energy and Sticking Probability of Nanoparticles Formed under Highly Supersaturated Environments and Importance of Microgravity Experiments

Int. J. Microgravity Sci. Appl. 2012p184
Yuki KIMURA 1, Takaya NOZAWA 2, Kyoko K. TANAKA 3, Hitoshi MIURA 1,Takao Maki 4 Katsuo TSUKAMOTO 1, Itsuki SAKON 5 and Yuko INATOMI 6
1 Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, 2 Institute for the Physics and Mathematics of the Universe, University of Tokyo, 3 Institute of Low Temperature Science, Hokkaido University, 4 Product Development Department 1, Micro-Imaging Systems Division, Olympus Corporation, 5 Department of Astronomy, Graduate School of Science, The University of Tokyo, 6 Institute of Space and Astronautical Science
The gas evaporation method, which is a typical smoke experiment, has a history of almost half century. Nevertheless, there has been almost no report concerning nucleation in a smoke in view of crystal growth. Here, we observed a nucleation process of thermally evaporated manganese vapor in an argon gas using a Mach-Zehnder type interferometer and showed that nanoparticles homogeneously condense only in very highly supersaturated environments. Condensation occurred at 660-785 K well below the equilibrium temperature and the degree of supersaturation was as high as ~5×104. Based on the condensation temperature and size of the condensed particles, which were measured by transmission electron microscopy, we determined the surface free energy and sticking coefficient for nucleation of Mn at 1106 ± 50 K to be 1.57 ± 0.35 J/m2 and 〖0.42〗_(-0.21)^(+0.42), respectively, by means of a semi-phenomenological (SP) nucleation theory. The large errors in these two parameters will be decreased by microgravity experiments.

© The Japan Society of Microgravity Applicaiton

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