Theoretical prediction of the structural and electronic properties of pseudocubic X3As4 (X=C, Si, Ge and Sn) compounds

✍ Scribed by Z. Charifi; H. Baaziz; B. Hamad

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 444 KB
• Volume: 404
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2009.01.043

✦ Synopsis

The structural and electronic properties of X 3 As 4 (X ¼ C, Si, Ge and Sn) compounds were investigated using density functional theory (DFT) calculations. We employed both the generalized-gradient approximation (GGA), which is based on exchange-correlation energy optimization to calculate the total energy and the Engel-Vosko (EV-GGA) formalism, which optimizes the corresponding potential for band structure calculations. The calculated lattice constant, bulk modulus and electronic band structure of pseudocubic X 3 As 4 (X ¼ C, Si, Ge and Sn) compounds are in good agreement with other theoretical results. The analysis shows that the hardest material is C 3 As 4 compound with a bulk modulus B 0 ¼ 106.5 GPa, while Si 3 As 4 , Ge 3 As 4 and Sn 3 As 4 have almost the same bulk modulus ranging from 51 to 68.5 GPa. Also we have presented the results of cohesive energies and we have given a detail discussion of the bond lengths and bond angles in the pseudocubic phase of group IV arsenides. Furthermore, band structure and density of states calculations show that Si 3 As 4 , Ge 3 As 4 and Sn 3 As 4 exhibit a semiconductor behavior with indirect gaps while C 3 As 4 exhibit a metallic behavior using both GGA and EV-GGA.