FIRST-PRINCIPLES STUDY OF ELECTRONIC STRUCTURAL,ELASTIC, AND THERMODYNAMIC PROPERTIES OF Sn-Bi ALLOYS

[摘要] Structural, electronic, elastic and the r modynamic properties of the SnxBi(16-x) (x=7 , 9 , 10 ,12 , 13 , 14 , 1515) solid solution alloys with tetragonal structure were investigated by meansof first principles calculations within the framework of density functional theory. T heresults of enthalpies of formation and cohesive energy show that the stability of the alloys increases with the decrease of the content Bi The electronic structure was furtherinvestigated to understand the underlying mechanism of the structural stability of theSnxBi(16-x) alloys. The single crystal elastic constants were calculated, showing that theSnxBi(16-x) alloys are mechanically stable structure. Then the bulk modulus B, Young’s modulus E, shear modulus G and Poison’s ratio  were estimated for polycrystalline SnxBi(16-x) alloys from the elastic constants. The ductility and plasticity of SnxBi(16-x) alloys w ere improved with decrease of the content of Bi. The elastic anisotropy was also furtherdiscussed in details. TThe substitution of Sn atoms by Bi makes the SnxBi(16-x) alloys elastically more isotropic for the {001} shear plane along the < direction . Finally,thermodynamic properties such as the Debye temperatures, the specific heat, and melting temperature for the SnxBi(16-x) alloys were estimated from elastic properties properties.

[学科分类] 生物技术

[关键词] SnxBi(16-x) alloys;First principles calculations;Elastic properties;The;r modynamic properties