Details

Autor(en) / Beteiligte

• Kuribayashi, Kazuhiko
• Nagashio, Kosuke
• Niwata, Kenji
• Kumar, M.S. Vijaya
• Hibiya, Taketoshi

Titel

Novel criterion for formation of metastable phase from undercooled melt

Ist Teil von

• Materials science & engineering. A, Structural materials : properties, microstructure and processing, 2007-03, Vol.449, p.675-679

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2007

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Undercooling a melt facilitates the preferential nucleation of a metastable phase. In the present study, the formation of metastable phases from undercooled melts was considered from the viewpoint of the competitive nucleation criterion. The classical nucleation theory shows us that the most critical factor for forming a critical nucleus is the interface free energy σ. Furthermore, Spaepen's negentropic model on σ generated the role of the scaling factor α that depends on the polyhedral order in the liquid and solid phases prominent in simple liquids such as the melt of monoatomic metals. In ionic materials such as oxides, however, in which oxygen polyhedrons including a cation at their center are the structural units both in the solid and liquid phases, the entropy of fusion, rather than α, can be expected to become dominant in the determination of σ. In accordance with this idea, using REFeO 3 as the model material (where RE denotes rare-earth elements) the entropy-undercooling regime criterion was proposed and verified.