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Analysis of the fragility of the Zr77Ni23 metallic glass based on low-temperature heat capacity measurements

We present an experimental investigation of the fragility and heat capacity of metallic glass Zr77Ni23. The ribbon sample was produced by melt-spinning technique. Glass transition temperature Tg obtained by differential scanning calorimetry with various heating rates was used to estimate fragility parameter m. Heat capacity measurements were performed in a wide temperature interval, ranging from 1.8 K up to room temperature, for as-cast and relaxed samples in different magnetic field strengths. Our results do not show any excess of ibrational density of states over the Debye contribution corresponding to the boson peak. Relaxation of the sample causes a slight decrease of Debye contribution consistent with the measured increase of Young modulus. The fact that no boson peak is observed in heat capacity, together with the obtained intermediate fragility of m=53, positions Zr77Ni23 well outside established correlations between fragility, boson peak strength, and glass forming ability.

metallic glass ; fragility ; heat capacity ; boson peak ; glass forming ability

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