Fast and direct determination of fragility in metallic glasses using chip calorimetry

Florian Spieckermann; Innozenz Steffny; Xilei Bian; Sergey Ketov; Mihai Stoica; Jürgen Eckert

doi:10.1016/j.heliyon.2019.e01334

Fast and direct determination of fragility in metallic glasses using chip calorimetry

Heliyon. 2019 Mar 13;5(3):e01334. doi: 10.1016/j.heliyon.2019.e01334. eCollection 2019 Mar.

Authors

Florian Spieckermann¹, Innozenz Steffny², Xilei Bian², Sergey Ketov², Mihai Stoica³, Jürgen Eckert^{1

2}

Affiliations

¹ Chair of Materials Physics, Montanuniversität Leoben, Jahnstraße 12, 8700 Leoben, Austria.
² Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, 8700 Leoben, Austria.
³ Laboratory of Metal Physics and Technology, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland.

Abstract

We directly determine the thermodynamic fragility index of two metallic glasses (Mg₆₅Cu₂₅Gd₁₀ and Au₄₉Cu_26.9Si_16.3Ag_5.5Pd_2.3) from fictive temperature shifts induced by a variation of the quenching rate using fast differential scanning calorimetry (FDSC). Recent chip calorimeters are able to achieve the cooling rates necessary to perform such an evaluation. For the Mg₆₅Cu₂₅Gd₁₀ and Au₄₉Cu_26.9Si_16.3Ag_5.5Pd_2.3 metallic glasses studied, we find very good agreement of the kinetic fragility index with literature data obtained by conventional calorimetry and rheology. The thermodynamic fragility indices are m=25.5 ± 1.5 for Mg₆₅Cu₂₅Gd₁₀ and m=50.3 ± 2.3 for Au₄₉Cu_26.9Si_16.3Ag_5.5Pd_2.3, respectively. The FDSC method discussed here allows for fast and reliable determination of the kinetic fragility of metallic glasses, and is thus competitive with high-frequency methods.

Keywords: Condensed matter physics; Materials science; Thermodynamics.