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Influences of Vacancy Concentration and Al Substitution on Structural, Electronic, and Elastic Properties of Nb 5 Si 3 from First‐Principles Calculations
Author(s) -
Xu Xia,
Zeng Wei,
Zhu Sheng-Hai,
Zhong Mi,
Hong Dan,
Li Ruo-Xi,
Liu Fu-Sheng,
Tang Bin,
Liu Qi-Jun
Publication year - 2021
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.202000591
Subject(s) - vacancy defect , materials science , ductility (earth science) , shear modulus , bulk modulus , electronic structure , modulus , elastic modulus , brittleness , condensed matter physics , crystallography , composite material , creep , chemistry , physics
The effects of vacancy concentration and Al substitution on the structural, electronic, and elastic properties of Nb 5 Si 3 are studied using first‐principles calculations. The formation energy, elastic modulus, and electronic properties of three different Nb vacancies in Nb 5 Si 3 are discussed in detail. With the increase in vacancy concentration, the obtained shear modulus, Young's modulus, and hardness of Nb vacancy decrease, which are lower than those of pristine Nb 5 Si 3 . The bulk modulus/shear modulus ( B / G ) ratio increases with the increase in Nb vacancy concentration. However, these vacancies result in the transition from brittleness to ductility, and Nb 5 Si 3 with 5% vacancy concentration exhibits ductile behavior. The calculation of electronic structure shows that these Nb vacancies change the local hybridization between Nb and Nb atoms. As the concentration increases, the position of the peak moves toward lower energy. It is predicted that vacancies can improve the ductility behavior of Nb 5 Si 3 .