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Description
Intermetallic compounds in the Sb-Zn system exhibit excellent thermoelectric properties, which can be further improved by indium alloying. Accurately describing the underlying In-Sb-Zn ternary phase diagram using phenomenological CALPHAD modeling relies on precise input datasets for all constituent phases. Among these, Zn5Sb4In2 represents the sole known ternary compound in the system. This work presents an ab initio study of the ground state of the ternary phase Zn5Sb4In2. Density functional theory (DFT) was employed to evaluate the equilibrium structural parameters, electronic properties. Additionally, the mechanical stability of the phase was established. Furthermore, dynamical stability was investigated using the Phonopy package. The calculated density of states revealed a narrow energy gap at the Fermi level, indicating the semiconducting character of Zn5Sb4In2. The calculated elastic properties confirm that Zn5Sb4In2 is mechanically stable, but phonon calculations revealed a dynamical instability of this compound at T = 0 K, consistent with its experimental observation only at elevated temperatures.
Acknowledgments
This study is a part of the project No. CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic. The authors acknowledge the Ministry of Education, Youth and Sports of the Czech Republic for the financial support of large research infrastructure INFRA CZ (ID:90254) at the IT4Innovations National Supercomputing Center.