title: Correlation between Fragility and the Arrhenius Crossover Phenomenon in Metallic, Molecular, and Network Liquids.
abstract: We report the observation of a distinct correlation between the kinetic fragility index m and the reduced Arrhenius crossover temperature θ_{A}=T_{A}/T_{g} in various glass-forming liquids, identifying three distinguishable groups. In particular, for 11 glass-forming metallic liquids, we universally observe a crossover in the mean diffusion coefficient from high-temperature Arrhenius to low-temperature super-Arrhenius behavior at approximately θ_{A}≈2 which is in the stable liquid phases. In contrast, for fragile molecular liquids, this crossover occurs at much lower θ_{A}≈1.4 and usually in their supercooled states. The θ_{A} values for strong network liquids spans a wide range higher than 2. Intriguingly, the high-temperature activation barrier E_{∞} is universally found to be ∼11k_{B}T_{g} and uncorrelated with the fragility or the reduced crossover temperature θ_{A} for metallic and molecular liquids. These observations provide a way to estimate the low-temperature glassy characteristics (T_{g} and m) from the high-temperature liquid quantities (E_{∞} and θ_{A}).
authors.affiliation: Department of Nuclear, Plasma, and Radiological Engineering,University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Jaiswal
authors.affiliation: Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA and Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Egami
authors.affiliation: Department of Physics and Institute of Materials Science and Engineering, Washington University, St. Louis, Missouri 63130, USA.
authors.forename: K F
authors.initials: KF
authors.lastname: Kelton
authors.affiliation: Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Schweizer
authors.affiliation: Department of Nuclear, Plasma, and Radiological Engineering,University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang