Predicting structural and dynamical behavior of La-based glasses and melts from the anharmonicity in their interatomic potential

Designing materials by alloying from the melt is a fascinating route but also a big challenge to the scientific community. The difficulty lies not only in the insufficient experimental data of the liquid state, but also in the lack of clear understanding of mechanisms relating to properties. In this work we studied binary La-TM melts as a model system using electrostatic levitation and synchrotron x-ray diffraction. From the measured specific volume and liquid structure, a relative loose packing in La-Cu liquid was found, compared to that of La-Ni and La-Co, with a positive excess volume. We show that this is results from a combination of steep repulsion and anharmonic attraction of the potential. Based on the potential anharmonicity, the deformation process in glasses can be predicted. Our findings not only provide deeper insights into the structural and dynamical properties induced by interatomic interaction, but also shed light on future designing from the characteristics of the constituents.