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Updated: Sep 15, 2025

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Metallic Bond Induces Soft Phonon Mode and Anharmonicity in Heusler Alloy
Hao-Xuan Liu1, Hai-Le Yan1, Nan Jia1
1Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang, 110819, China.
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The fruitful functional performances of metastable Heusler alloys originate from the martensitic transformation driven by the transverse acoustic soft phonon mode, regulated by anharmonicity. However, the origins of the soft mode and the anharmonicity in these alloys remain unclear. In this work, using ab-initio calculations combined with self-consistent phonon theory (SCPH) and compressed sensing techniques in machine learning, a link among chemical bonding, long-range interaction, soft mode, and anharmonicity is established using Ni2MnGa as a model system. The long-range interaction rooted in metallic bonding between spin-down d-orbitals of Ni─Ni induces phonon softening and significant anharmonicity. This finding offers new insights into the role of metallic bonding and long-range interactions in martensitic transformation, providing a fresh perspective for the design and optimization of phase transition functional alloys.
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