Structural, Mechanical, Anisotropic, and Thermal Properties of AlAs in oC12 and hP6 Phases under Pressure
AbstractThe structural, mechanical, anisotropic, and thermal properties of oC12-AlAs and hP6-AlAs under pressure have been investigated by employing first-principles calculations based on density functional theory. The elastic constants, bulk modulus, shear modulus, Young’s modulus, B/G ratio, and Poisson’s ratio for oC12-AlAs and hP6-AlAs have been systematically investigated. The results show that oC12-AlAs and hP6-AlAs are mechanically stable within the considered pressure. Through the study of lattice constants (a, b, and c) with pressure, we find that the incompressibility of oC12-AlAs and hP6-AlAs is the largest along the c-axis. At 0 GPa, the bulk modulus B of oC12-AlAs, hP6-AlAs, and diamond-AlAs are 76 GPa, 75 GPa, and 74 Gpa, respectively, indicating that oC12-AlAs and hP6-AlAs have a better capability of resistance to volume than diamond-AlAs. The pressure of transition from brittleness to ductility for oC12-AlAs and hP6-AlAs are 1.21 GPa and 2.11 GPa, respectively. The anisotropy of Young’s modulus shows that oC12-AlAs and hP6-AlAs have greater isotropy than diamond-AlAs. To obtain the thermodynamic properties of oC12-AlAs and hP6-AlAs, the sound velocities, Debye temperature, and minimum thermal conductivity at considered pressure were investigated systematically. At ambient pressure, oC12-AlAs (463 K) and hP6-AlAs (471 K) have a higher Debye temperature than diamond-AlAs (433 K). At T = 300 K, hP6-AlAs (0.822 W/cm·K−1) has the best thermal conductivity of the three phases, and oC12-AlAs (0.809 W/cm·K−1) is much close to diamond-AlAs (0.813 W/cm·K−1). View Full-Text
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Zhang, W.; Chai, C.; Song, Y.; Fan, Q.; Yang, Y. Structural, Mechanical, Anisotropic, and Thermal Properties of AlAs in oC12 and hP6 Phases under Pressure. Materials 2018, 11, 740.
Zhang W, Chai C, Song Y, Fan Q, Yang Y. Structural, Mechanical, Anisotropic, and Thermal Properties of AlAs in oC12 and hP6 Phases under Pressure. Materials. 2018; 11(5):740.Chicago/Turabian Style
Zhang, Wei; Chai, Changchun; Song, Yanxing; Fan, Qingyang; Yang, Yintang. 2018. "Structural, Mechanical, Anisotropic, and Thermal Properties of AlAs in oC12 and hP6 Phases under Pressure." Materials 11, no. 5: 740.
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