摘要
运用第一性原理研究了Mg-Sb合金中典型沉淀相α-Mg3Sb2的几何、电子结构和力学性能.结构优化得到的晶格常数和形成能与实验值符合很好.电子结构分析表明,具有半导体性质的α-Mg3Sb2带隙为0.303eV,是间接带隙半导体.通过计算得到了α-Mg3Sb2的弹性常数,进而得到模量、泊松比等力学参数,对力学参数进行分析发现,α-Mg3Sb2有很好的延展性而塑性相对较差.通过对α-Mg3Sb2施加应变前后态密度的变化分析,发现对于六角结构的α-Mg3Sb2,与剪切模量相关的C11+C12,C33/2和与体模量相关的C11+C12+2C13+C33/2对体积变化不保守,而(C11-C12)/4和C44对体积变化保守.
First principles calculations have been carded out to investigate the electronic structure and the mechanical properties of α-MgaSb2. The optimized structural parameters and formation energy are in good agreement with the experimental values. The electronic structure is also given, indicating that α-Mg3Sb2 is indirect-semiconductor. The obtained energy band gap of α-Mg3 Sb2 is 0.303 eV. The elastic constaint C11 of a-Mg3Sb2 has been calculated, then the mechanical parameters such as moduli, Possion＇s ratio, etc are abtained. By analysizing the mechanical parameters it is found that α-Mg3Sb2 has good ductility and relatively poor plasticity. In the end, the volume conservation of α-Mg3Sb2 is discussed in terms of the total density of states before and after deformations. From the results, it can be seen that the shears corresponding to （ C11 - C12 ）/4 and C44 are almost volume conserving whereas the shears corresponding to C11 ＋ C12, C33/2 and the bulk modulus related to Ca ＋ C12 ＋ 2 C13 ＋ C33/2 are not volume conserving.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第F06期216-223,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:50861002)
湖南省自然科学基金(批准号:08JJ6001)
材料设计与制备技术湖南省重点实验室开放课题(批准号:KF0803)
广西大学科研基金(批准号:X071117)资助的课题~~
