An ordered metallic glass solid solution phase that grows from the melt like a crystal
Résumé
We report structural studies of an Al-Fe-Si glassy solid that is a solid solution phase in the classical thermodynamic sense. We demonstrate that it is neither a frozen melt nor nanocrystalline. The glass has a well-defined solubility limit and rejects Al during formation from the melt. The pair distribution function of the glass reveals chemical ordering out to at least 12Å that resembles the ordering within a stable crystalline intermetallic phase of neighboring composition. Under isothermal annealling at 305 °C the glass first rejects Al, then persists for approximately 1 h with no detectable change in structure, and finally is transformed by a first-order phase transition to a crystalline phase with a structure that is different from that within the glass. It is possible that this remarkable glass phase has a fully ordered atomic structure that nevertheless possesses no long-range translational symmetry and is isotropic.
Mots clés
Glass transition
Aluminum
Crystalline materials
Distribution functions
Glass
Intermetallics
Metallic glass
Nanocrystals
Phase transitions
Solid solutions
X ray scattering
Classical thermodynamics
First-order phase transitions
Intermetallic phase
Pair distribution function analysis
Pair distribution functions
Solid solution phase
Structural studies
Translational symmetry
Crystal atomic structure
Domaines
Physique [physics]
Origine : Fichiers produits par l'(les) auteur(s)
Loading...