Atomistic simulation on the site preference and mechanical properties of Th3Co4+xAl12−x and U3Co4+xAl12−x

An atomistic study is presented on the phase stability, site preference and lattice constants of the actinide intermetallic compounds Th3Co4+xAl12−x and U3Co4+xAl12−x. Calculations are based on a series of interatomic pair potentials related to the actinides and transition metals, which are obtained by a strict lattice inversion method. The lattice constants of Th3Co4+xAl12−x and U3Co4+xAl12−x are calculated for different values of x. The site preference of Co atoms at Al sites is also evaluated and the order is given as 6h, 4f, 2b and 12k for Th3Co4+xAl12−x, and 6h, 4f, 12k and 2b for U3Co4+xAl12−x. In addition, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for the actinide compounds with complex structures.