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运用基于第一性原理的平面波赝势法研究了L12-Al3Li金属间化合物中Li原子空位和Al原子反位缺陷对Al3Li热力学性能的影响,结果表明:Al反位缺陷易与周围原子形成局域共价键,使晶体体积增大,而Li空位缺陷却减小了晶体体积.Li空位缺陷使L12-Al3Li的硬度增加,延展性降低,德拜温度值升高.Al反位缺陷降低了晶体的硬度,增加了延展性,降低了德拜温度值.在德拜温度以下,Li空位缺陷减小了L12-Al3Li的热容,而Al反位缺陷使晶体热容增大.晶格畸变对L12-Al3Li晶体的热力学性能有重要影响.
The effects of Li atom vacancy and Al atom anti-position defect in L12-Al3Li intermetallic compound on the thermodynamic properties of Al3Li were studied by the plane wave pseudopotential method based on the first principle. The results show that Al anti-defect is easy to form local Covalent bond, the crystal volume increases, while the Li vacancy defects reduce the volume of the crystal.Li vacancy defects make the hardness of L12-Al3Li increase, the ductility decreases, Debye temperature value increases.Al anti-defects reduce the crystal The ductility decreases, the Debye temperature decreases, and below the Debye temperature, Li vacancies reduce the heat capacity of L12-Al3Li, whereas the Al anti-flaw increases the heat capacity of the crystal. The thermodynamic properties of L12-Al3Li crystals have important implications.