Tunable magnetic anisotropy of Os-Ru dimer on 2D transition metal chalcogenides substrates

The precise manipulation of atoms enables the creation of distinct materials from the bottom up to construct devices with breakthrough performance, especially in the field of quantum technologies. A large magnetic anisotropy energy (MAE) is important to realize bit storage of information in magnetic memory devices. As the smallest magnetic nanostructure, substrate-supported transition metal dimers are potential atomic-scale storage medium to obtain large MAEs. Using high-throughput first-principles calculations, we have performed a systematic investigation of the MAE of 76 heterodimensional systems consisting of zero-dimensional Os-Ru dimer and experimentally synthesized two-dimensional transition metal dichalcogenides (TMDs). Huge MAEs in the range of 102.09–247.69 meV were found in 13 of these heterodimensional systems. In particular, the Os-Ru@T-ZrSe2 with the largest MAE of 247.69 meV corresponds to a theoretical blocking temperature (67 K) in terms of a relaxation time of 10 years and a storage density of 281 Tb·inch−2. The underlying mechanism for the significant enhancement of MAE is attributed to the rearrangement of the in-plane molecular orbitals near the Fermi level, which is closed relative to the electron transfer capability between the Os-Ru dimer and the TMD substrates. In addition, we have also constructed a heat map for TMD-supported Os-Ru dimer, showing the degree of correlation between MAEs and feature descriptors. Our work not only suggests an effective way to improve MAE of transition metal dimers but also extracts relatively simple rules for substrate selection.