Diffusion-controlled agglomeration (dewetting) of thin metal films
Event details
| Date | 15.09.2014 |
| Hour | 13:15 › 14:15 |
| Speaker | Prof. Eugen Rabkin, Department of Materials Science and Engineering Technion, Israel Institute of Technology, Haifa |
| Location | |
| Category | Conferences - Seminars |
We report the results of our studies of solid state dewetting (agglomeration) of thin Au, Fe, and Ni films, and of Au-Fe bi-layers deposited on sapphire substrate. At the final stages of agglomeration an array of single crystalline faceted nanoparticles is produced. These particles exhibit stable faceted shapes that are far from those predicted by equilibrium considerations. We discuss high thermal stability of faceted particles in terms of slow mass transport along the singular atomically flat facets [1]. In the case of heteroepitaxial Ni films and Au-Fe bilayers, the formation of highly faceted pinholes to the substrate is accompanied by the nucleation and growth of twin boundaries parallel to the substrate. These boundaries allow nucleating of defects at the side facets of the pinhole, thus enabling its growth. A slow pace of self-diffusion along the singular facets increases the importance of alternative short-circuit diffusion paths, such as grain boundaries and film-substrate interface. We demonstrate that holes expansion and simultaneous growth of hillocks in Fe thin films during initial stages of dewetting can be described in terms of grain boundary diffusion of Fe atoms from the holes to the hillocks. We also describe the initial stages of dewetting of thin Au and Ni films in terms of a combination of grain boundary and film-substrate interface diffusion, and grain boundary sliding. Our results indicate that a classical hierarchy of short-circuit diffusion paths is not applicable on the nanoscale [2].
References:
1. O. Malyi, E. Rabkin
The effect of evaporation on size and shape evolution of faceted gold nanoparticles on sapphire
Acta mater. 60 (2012) 261-268
2. D. Amram, L. Klinger, N. Gazit, H. Gluska, E. Rabkin
Grain boundary grooving in thin films revisited: the role of interface diffusion
Acta mater. 69 (2014) 386-396
Bio: Eugen Rabkin was born in Gomel, Byelorussia (former USSR). He studied materials science in Moscow, and obtained his Ph.D. from the Institute of Solid State Physics of the Russian Academy of Sciences in 1991. Between 1992 and 1997 he was a Post-doctoral researcher at the Max Planck Institute for Metal Research in Stuttgart, Germany. Since 1997 he is a faculty member in the Department of Materials Science and Engineering at the Technion-Israel Institute of Technology. He co-authored about 200 papers in peer-reviewed journals. His research interests include diffusion and phase transformations in solids, mechanical properties of materials at the nanoscale, and hydrogen storage in nanocrystalline solids.
http://materials.technion.ac.il/eugen-rabkin-metals-interfaces-diffusion/
References:
1. O. Malyi, E. Rabkin
The effect of evaporation on size and shape evolution of faceted gold nanoparticles on sapphire
Acta mater. 60 (2012) 261-268
2. D. Amram, L. Klinger, N. Gazit, H. Gluska, E. Rabkin
Grain boundary grooving in thin films revisited: the role of interface diffusion
Acta mater. 69 (2014) 386-396
Bio: Eugen Rabkin was born in Gomel, Byelorussia (former USSR). He studied materials science in Moscow, and obtained his Ph.D. from the Institute of Solid State Physics of the Russian Academy of Sciences in 1991. Between 1992 and 1997 he was a Post-doctoral researcher at the Max Planck Institute for Metal Research in Stuttgart, Germany. Since 1997 he is a faculty member in the Department of Materials Science and Engineering at the Technion-Israel Institute of Technology. He co-authored about 200 papers in peer-reviewed journals. His research interests include diffusion and phase transformations in solids, mechanical properties of materials at the nanoscale, and hydrogen storage in nanocrystalline solids.
http://materials.technion.ac.il/eugen-rabkin-metals-interfaces-diffusion/
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Practical information
- General public
- Free
Organizer
- Holger Frauenrath
Contact
- Holger Frauenrath