Metallic glacial glass

Abstract

A novel glassy substance known as metallic glacial glass has been recently discovered by liquid-to-liquid transition or glaciation of some metallic-glass forming liquids. Without changing the original composition and amorphous nature of the material, glaciation gives the glass intriguing properties, including high strength, high hardness, and improved thermal stability. The metallic glacial glass can be preserved at ambient temperature, above which sits the glass transition temperature, making it suitable for material applications that have not been possible with other glacial phases in other liquid systems. A brief history of the glacial phase in the triphenyl phosphite molecular liquid with similar thermodynamics and kinetics to metallic glacial glass is introduced, emphasizing the common questions faced. Different phase-transition pathways for supercooled liquids of principal crystallization, primary crystallization, quasicrystallization, short-range ordering, phase separation, mesophase formation, and glaciation are compared, highlighting the large enthalpy change of glaciation enabling a new landscape of the glassy state. Requirements for identifying glaciation out of other possibilities are specified. Future research directions regarding both scientific and practical needs are proposed. The review concludes with a roadmap that may lead to more compositions of metallic glacial glasses.

Keywords

• metallic glass
• glacial glass
• glaciation
• liquid-to-liquid transition
• calorimetry