Ab initio studies of Electronic Structure and magnetic properties of RAl(Mg)3 (R= Ce, Pr, Nd, Sm and Gd) alloys

Abstract

We report the magnetic behaviour of RAl3 and R(Mg)3 (R= Ce, Pr, Nd, Sm and Gd) alloys studied through ab initio calculations based on density functional theory (DFT). The magnetic moments obtained from the all electron full potential calculations suggest strong magnetic instability in Ce compounds. The compounds with heavier rare earths (Pr, Nd, and Gd) exhibit local moment with high orbital moment, consistent with crystal field splitting of the 4fn ground state. The results obtained for SmAl3 and SmMg3 suggest possible valence fluctuation. Our calculated magnetic moments closely agree with experimental results reported in literature. We have also calculated the magnetic hyperfine field and its spin and orbital contributions. While, the total hyperfine field is dominated by the contribution from orbital magnetic moment, the Fermi contact contribution to the hyperfine field is found to scale with the spin projection factor (gJ−1)J. The calculated hyperfine field values are found to show good agreement with available experimental results.