Mechanical and magnetic properties of CeAuGa3 from first-principles calculations

Abstract:

In this paper, the structural properties and the mechanical stability of Ce-based intermetallic CeAuGa3 are studied based on the first-principles calculations. The full sets of elastic constants, the associated macroscopic elastic parameters (bulk, shear and Young’s moduli, Poisson ratio), and phonon dispersion have been determined, indicating that the I4mm structure is both mechanically and dynamically stable. By calculating the spin exchange interaction between cerium ions, we have analyzed several possible ordered spin states of CeAuGa3, and found that the ground state of CeAuGa3 prefers to be ferromagnetic ordering. The positive (ferromagnetic) exchange coupling between the first and second nearest neighbors within each ab layer plays a dominant role, while the third nearest neighbour ferromagnetic interaction between adjacent ab layers of Ce ions is relatively weak.