Mechanical and thermophysical properties of actinide monocarbides

摘要

This paper describes the mechanical and thermophysical properties of actinide monocarbides AnCs (An=Np and Cm) as a function of temperature and crystallographic direction. The temperature-dependent second- and third-order elastic constant (SOECs and TOECs) have been computed first using Coulomb and Born-Mayer potential up to second nearest neighbor. SOECs have been applied to find out mechanical constant such as bulk modulus, shear modulus, tetragonal modulus, Poisson's ratio and Zener anisotropy for the prediction of futuristic performance of the NpC and CmC. We also found the value of G/B 0.59 for the chosen materials, which indicates that NpC and CmC have brittle nature. The computed elastic constants are further applied directly to indirectly find out the ultrasonic velocity, Gruneisen parameters, pressure derivative, Debye temperature, micro-hardness, Breazeale's nonlinearity parameter, thermal relaxation time and thermal conductivity. These evaluated parameters were finally used to compute ultrasonic attenuation of the NpC and CmC along 100 , 110 and 111 directions at room temperature. The behavior of the obtained results of this investigation has been compared with similar type of materials.