Mechanical properties, anisotropy and hardness of group IVA ternary spinel nitrides

作者：Ding Ying Chun^*; Chen Min

来源：Molecular Physics, 2013, 111(20): 3054-3066.

DOI：10.1080/00268976.2013.766370

• elastic property
• intrinsic hardness
• Debye temperature

In this work, new ternary cubic spinel structures are designed by the substitutional method. The structures, elasticity properties, intrinsic hardness and Debye temperature of the cubic ternary spinel nitrides are studied by first principles based on the density-functional theory. The results show that -CSn2N4, -SiC2N4, -GeC2N4 and -SnC2N4 are not mechanically stable. The elastic constants C-ij of these cubic spinel structures are obtained using the stress-strain method. Derived elastic constants, such as bulk modulus, shear modulus, Young's modulus, Poisson coefficient and brittle/ductile behaviour are estimated using Voigt-Reuss-Hill theories. The B/G value, the Poisson's ratio and anisotropic factor are calculated for eight ternary stable crystals. Based on the microscopic hardness model, we further estimate the Vickers hardness of all the stable crystals. From the calculated hardness of the stable group IVA ternary spinel nitrides by Gao's and Jiang's methods, it is observed that the stable group IVA ternary spinel nitrides are not superhard materials except for -CSi2N4. Furthermore, the Debye temperature for the eight stable crystals is also estimated.

• 出版日期2013-10-31
• 单位成都信息工程大学