Glass transition with decreasing correlation length during cooling of Fe50Co50 superlattice and strong liquids

Abstract

The glass transition GT is usually thought of as a structural arrest that occurs during the cooling of a liquid, or sometimes a plastic crystal, trapping a metastable state of the system before it can recrystallize to stabler forms1. This phenomenon occurs in liquids of all classes, most recently in bulk metallic glassformers2. Much theoretical interest has been generated by the dynamical heterogeneity observed in cooling of fragile liquids3, 4, and many have suggested that the slow-down is caused by a related increasing correlation length 5-9. Here we report both kinetics and thermodynamics of arrest in a system that disorders while in its ground state, exhibits a large !Cp on arrest (!Cp = Cp,mobile - Cp,arrested), yet clearly is characterized by a correlation length that is decreasing as GT is approached from above. We show that GT kinetics in our system, the disordering superlattice Fe50Co50, satisfy the kinetic criterion for ideally 'strong' glassformers10, and since !Cp behavior through Tg also correlates10, we propose that very strong liquidsand very fragile liquids exist on opposite flanks of an order-disorder transition - one that is already known for model systems.

References in corpus (8)

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• Direct experimental evidence of a growing length scale accompanying the glass transition
• Pressure Dependence of Fragile-to-Strong Transition and a Possible Second Critical Point in Supercooled Confined Water
• Thermodynamics and Dynamics of the Two-Scale Spherically-Symmetric Jagla Model of Anomalous Liquids
• One micron length scale controls kinetic stability of low energy glasses
• Insights into glass formation and glass transition in supercooled liquids, by study of related phenomena in crystals
• Revisiting the slow dynamics of a silica melt using Monte Carlo simulations
• Gaussian excitations model for glass-former dynamics and thermodynamics

Cited by in corpus (6)

• Glass transitions, semiconductor-metal (SC-M) transitions and fragilities in Ge-V-Te (V=As, or Sb) liquid alloys: the difference one element can make
• Fragile-to-fragile Liquid Transition at Tg and Stable-Glass Phase Nucleation Rate Maximum at the Kauzmann Temperature TK
• Glass phase and other multiple liquid-to-liquid transitions resulting from two liquid phase competition
• A Dramatically Growing Shear Rigidity Length Scale in a Supercooled Glass Former ($NiZ{r}_2$)
• Probing Local Structure in Glass by the Application of Shear
• Activation energy spectrum for relaxation and polyamorphism in an ultra-viscous metallic glass former