Magnetism and Magnetocrystalline Anisotropy in Low-Dimensional Rh and Ir

We report the ab initio calculations for angle resolved anisotropy in spin and orbital moment for zigzag chains of Rh and Ir. We present the site specific information about the spin and orbital moment in Rh and Ir zigzag chains. We observed a significant magnetocrystalline anisotropy energy (MAE) up to 17.5 meV/atom for Ir chains. We show that at the angles off the principal axes, orbital (L) and spin (S) angular momenta have different dynamics. We found a strong non-collinearity in the direction of spin and orbital moments in the plane perpendicular to the axis of the chains. The maximum orbital moments for the chains are along the axis of the chains. A ferromagnetic coupling has been observed in the zigzag chains of Rh as well as Ir. A key feature of the study is the alteration of the occupation states on changing the direction of magnetization vector, which results in switching the direction of MAE.