Phase-Change Materials: Vibrational Softening upon Crystallization and its Impact on Thermal Properties
| Autor: | Gunnar Bruns, Peter Zalden, Matthias Wuttig, Hans-Christian Wille, Noboru Yamada, Masaki Takata, Rie Kojima, Raphaël P. Hermann, Shin-ichi Shamoto, Toshiyuki Matsunaga, Shinji Kohara, Ilya Sergueev, Masugu Sato, Tomoya Uruga, Hajime Tanida |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Phonon Thermodynamics Conductivity Condensed Matter Physics Thermal conduction Electronic Optical and Magnetic Materials Amorphous solid law.invention Biomaterials Condensed Matter::Materials Science Crystallography Thermal conductivity law Phase (matter) Electrochemistry Crystallization ddc:620 Softening |
| Zdroj: | Advanced functional materials 21, 2232-2239 (2011). doi:10.1002/adfm.201002274 |
| DOI: | 10.1002/adfm.201002274 |
| Popis: | Crystallization of an amorphous solid is usually accompanied by a signifi cant change of transport properties, such as an increase in thermal and electrical conductivity. This fact underlines the importance of crystalline order for the transport of charge and heat. Phase-change materials, however, reveal a remarkably low thermal conductivity in the crystalline state. The small change in this conductivity upon crystallization points to unique lattice properties. The present investigation reveals that the thermal properties of the amorphous and crystalline state of phase-change materials show remarkable differences such as higher thermal displacements and a more pronounced anharmonic behavior in the crystalline phase. These fi ndings are related to the change of bonding upon crystallization, which leads to an increase of the sound velocity and a softening of the optical phonon modes at the same time. |
| Databáze: | OpenAIRE |
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