Elastic and thermal properties of carbides of U, Pu, and Am. (October 2019)

• Record Type: Journal Article
• Authors: Verma, Alok Kumar; Kaushik, Shivani; Singh, Devraj; Yadav, Raja Ram
• Is Part Of: Journal of physics and chemistry of solids. Volume 133(2019)
• Page Start: 21
• Page End: 27
• Publication Date: 2019-10
• Subjects: Actinide monocarbide -- Elastic property -- Mechanical property -- Thermal property -- Ultrasonic property; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2019.05.006
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: In this study, we investigated the behaviors of three representative actinide monocarbides (AnCs, where An = U, Pu, and Am) in terms of their superior mechanical and thermo-elastic properties. Coulomb and Born–Mayer potentials were used to calculate the temperature-dependent second order and third order elastic constants up to the second nearest neighbor. The Voigt–Reuss–Hill approximation was employed to compute the values of Young's modulus (Y), Zener anisotropy ratio (A), shear modulus (G), bulk modulus (B), Poisson's ratio (σ), and Pugh's indicator (B/G) using second order elastic constants. The Born stability criteria and Vicker's hardness parameter ( H ν ) were analyzed to determine the strength and nature of the materials. The Debye average velocities and Breazeale's nonlinearity parameters were calculated in the temperature range from 100 to 500 K. Thermal properties such as the lattice thermal conductivity, thermal relaxation time, crystal energy density, and acoustic coupling constant were computed at different temperatures and along various directions. The longitudinal and shear components of ultrasonic attenuation were evaluated along the three crystallographic directions comprising <100>, <110>, and <111>. The temperature- and direction-dependent ultrasonic properties were correlated with other thermo-physical properties to extract important information such as the material strength and thermal conductivity in order to assess the microstructural quality and nature of the materials, which are useful for industrial applications. Highlights: Superior elastic and mechanical properties of UC compared with PuC and AmC. AnCs satisfy Born stability criteria. AnCs exhibit brittle behavior and non-central nature of interaction potential. Strong dependence of ultrasonic attenuation on crystallographic direction.