Electronic structures and magnetic properties of R B4 (R=Yb,Pr,Gd,Tb,Dy)

Abstract

Most rare-earth tetraborides R B4 have antiferromagnetic ground states except for Yb B4 and Pr B4. We have investigated the electronic structures and magnetic properties of R B4 (R=Yb,Pr,Gd,Tb,Dy) employing the first-principles total energy band method. It is found that Yb B4 has the paramagnetic ground state, while the other tetraborides are in the magnetic ground state, which is in agreement with experiments. We have obtained the spin and orbital magnetic moments and discussed the importance of the spin-orbit interaction and the on-site Coulomb repulsion (U) in these systems. © 2009 American Institute of Physics.