Dynamic of Materials at Nano Meter Scale by Time Resolved Microscopy
Yossi LEREAH
Faculty of Engineering
Tel Aviv University
We study the dynamic of various processes at nano meter scale by electron and
optical microscopy:
1.
The growth of a crystalline phase in amorphous matrix by Conventional
Transmission Electron Microscope (CTEM). We have found that the crystallineamorphous interface propagates by steps of characteristic length of 10nm and
characteistic time of 0.1 sec.
*Y.Lereah , A. Gladkikh, S. Buldyrev and H.E. Stanley, Physical Review Letters,
83 784 (1999)
2. The growth of Ge crystal by High Resolution Electron Microscopy. We
demonstrate, at the atomic scale, layer by layer growth as well as hetronucleation on the interface.
*Y.Lereah and J.M.Penisson – to be published
3.
Surface Melting in Nano particles by CTEM. We demonstrate that the molten
layer increases with temperature and decreases with the radius of the particles.
*Y. Lereah, G. Deutscher, P. Cheyssac and R. Kofman. Europhysics Letters 12
709 (1990)
4.
Structural instabilities of nano particles by HREM. We correlated the
instabilities with spontaneous movement of twins defects. We also demonstrate
that the process is thermally activated.
*T. Ben-David, Y. Lereah, G. Deutscher, J.M. Penisson, A. Bourret, R. Kofman
and P. Cheyssac , Physical Review Letters, 78, 2585 (1997)
*J.M. Penisson, Y. Lereah and B. Pantel, Microscopy Research and Technique 36
438 (1997)
5.
Wetting-Reaction of metals by Differential Interference Contrast (DIC)
optical microscopy. We detect a few nanometer thin film while mercury wets and
react with silver. We study the dynamic of the process.
*M.Beer, H.Teitelabaum and Y.Lereah - to be published
Video demonstrations of the above will be available during the workshop.