Sm cluster on hexagonal boron nitride supported by Ir(111): Formation of magnetic cluster superlattice Sm13[formula omitted]h-BN[formula omitted]Ir(111)

Abstract

The goal toward the ultimate density limit of magnetic information storage is now focused on the creations of identical magnetic clusters as well as their arrangements on a template surface for obtaining an equidistant, monodisperse and equally oriented pattern. To achieve this goal, the combination of rare-earth (RE) cluster and specific template is a viable route, e.g., h-BN monolayer on Ir(111) surface within a corrugated moiré structure (h-BN|Ir(111)) can act as a promising template to steer the intrinsically magnetic RE cluster in a well-defined orientation. Combining abinito molecular dynamic (AIMD) simulation and spin–orbital coupling density function theory (DFT) calculations, we report that magnetic Sm13 cluster can be stably deposited at the pore region of h-BN|Ir(111) template. The low-lying moiré region potential of h-BN|Ir(111) template, stable icosahedron structure of Sm13 cluster, and strong hybridization of Sm-5d6s orbitals with B/N-sp orbitals, play the synergetically roles to form Sm13@h-BN|Ir(111) cluster superlattice. The local magnetic moments of Sm atoms in Sm13 cluster are found to be robust against the structural configuration, localized site and inter-atom magnetic coupling, because their highly localized 4f states hybridize less with the spd states. Nevertheless, different deposition orientations and consequently the altered bonding interactions between Sm atoms and h-BN monolayer lead to different magnetic orders among Sm atoms. The appearances of large magnetic moment and giant magnetic anisotropy energy (MAE) of Sm13 cluster as well as its high deposition stability render Sm13@h-BN|Ir(111) for potential application of magnetic storage.