Low-temperature nano-material science
Size scale of nanometer sized particles is in meso-scale between molecular clusters and bulk material. In the size scale, materials have characteristic properties such as lower melting point as much as 50% and more than 9 orders larger diffusion coefficients compared with those of the bulk material. During a material formation from atoms or molecules, the material passes through the size of meso-scale, and then, should be grown via unexpected processes. Indeed, we have found some nucleation process with new phenomena; nanoparticles are nucleated via liquid phase even which formed from a vapor phase and nanoparticles fused together to be a larger particle to decrease their total surface energy, when they contact. These studies have mainly been performed in inorganic materials and not in ice and related materials (low temperature nanomaterials). In this project, we focus on the formation process of low temperature nanoparticles taking into account characteristic phenomena in meso-scale and will obtain physical parameters, which will be used to understand the formation process of snow in a cloud and/or ice in the solar nebula 4.6 billion years ago.
Making a new field of "low-temperature nanomaterial science" based on experimental studies elucidating its characteristic properties and noble phenomena is an objective in this project. At first, we will construct a new formation method of low-temperature nanomaterials and its observation methods using a transmission electron microscope, and then, obtain physical parameters such as surface free energy and sticking probability.
Exceptionality of the program
This project has important aspects related to several fields including nano-science, surface-reaction chemistry, atomic probe analysis, theoretical simulation, crystal growth and microgravity science. Therefore, experimentalists, theoreticians and technicians will contribute for interdisciplinary studies in the project.
In addition to the present experimental apparatus in our institute, we will develop a new experimental system to make low-temperature nanomaterials. Present major apparatus are ultra-cold and -high vacuum transmission electron microscope, fluid-reaction transmission electron microscope, high spatial resolution optical microscope, in-situ observation system for homogeneous nucleation environment, and scanning probe microscope and so on.
|Yuki Kimura||Institute of Low Temperature Science, Hokkaido University|
|Yuko Inatomi||Institute of Space and Astronoutical Science, JAXA|
|Yuki Araki||Graduate School of Science, Kobe University|
|Hiroki Nada||National Institute of Adanced Industrial Science and Technology|
|Toshiki Sugimoto||Graduate School of Science, Kyoto University|
|Akio Kono||Japan Agency for Marine-Earth Science and Technology|
|Hitoshi Miura||Graduate School of Natural Sciences, Nagoya City University|
|Hidekazu Tanaka||Institute of Low Temperature Science, Hokkaido University|
|Hiroshi Hidaka||Institute of Low Temperature Science, Hokkaido University|
|Ken Nagashima||Institute of Low Temperature Science, Hokkaido University|
|Takeshi Chigai||Institute of Low Temperature Science, Hokkaido University|