Harnessing Colossal Magnetic Anisotropy in Sandwiched 3d²-Metallocenes

Abstract

Single-molecule magnets are gaining attention in recent years with the growing focus on achieving higher barriers of magnetization reversal. Metallocenes, owing to their unique sandwiched structure, assure themselves as plausible molecular systems for the development of novel single-molecule magnets (SMMs). Here in this work, we have explicitly investigated metallocenes of firstrow transition elements, along with their one-electron-oxidized (cationic) and -reduced (anionic) analogues, for their magnetic anisotropies by adopting multireference ab initio calculations. Herein, we report a high magnetic anisotropy for 3d 2 systems among all 3d-metallocenes.

Unravelling the robustness of magnetic anisotropy of a nickelocene molecule in different environments: a first-principles-based study

“…Our conclusion agrees well with the previous reports. 76,79 Based on the above data we can obtain the final MAE values of Nc in Nc/Cu(100) and Nc/Cu/Cu(100) composites as D = 3.34, E = 0 and D = 3.51, E = 0, respectively. Such a minor difference in the MAE is consistent with the experimental changes found for D for Nc on the surface and on the tip.…”

“…[52][53][54][55][56][57] These apparent discrepancies are largely attributed to the adopted density functional approximations suffering severely from the static correlation error, which cannot capture the obvious multireference character of the low-energy spin excitations among the nearly degenerate TM d orbitals. 74,75 On the other hand, highlevel quantum chemistry methods, such as the CASSCF method can predict MAE of kinds of organometallic molecules more reliably, [76][77][78][79] but their applications are limited to isolated molecules because of the high computational cost if applied in molecule-substrate composite systems. To reveal how the spin and MAE of Nc are preserved in different environments, we adopt the embedding method which combines the DFT and CASSCF methods to evaluate the MAE of Nc in the Nc/Cu (100) and Nc/Cu/Cu(100) composites.…”

Impact of Spin-Phonon Coupling on Magnetic Relaxation of a Co(II) Single-Molecule Magnet

“…The magnetic anisotropy of such complexes is strongly dependent on the symmetry as well as the surrounding environment around the central metal. 41 Hence, it becomes crucial to look into the electronic structure of the system in order to have a comprehensive understanding of the origin of slow relaxation of magnetization. [42][43][44] Into the bargain, Gereka and co-workers have explained the impact of the distortion of the coordination sphere on the slow relaxation for Co II N 6 trigonal prismatic cationic complexes.…”

Single-Molecule Magnetism in Linear Fe(I) Complexes with Aufbau and Non-Aufbau Ground States

“…To overcome these ligand field effects, the low-coordinate complexes (coordination number <4) renewed the interest of researchers, since they favor degenerate ground states resulting in minimal quenching of orbital angular momentum. To this end, linear or quasi-linear two-coordinate complexes emerge as the choicest complexes for mitigating these effects and eventually resulting in large anisotropic energy barriers. − The stability and isolation of these low coordinated complexes necessitate sterically encumbered ligands. A copious number of two- and three-coordinate complexes featuring the Fe­(II) center are already reported with intriguing magnetic properties. ,,− Nearly, all these complexes anchorage sterically bulky ligands.…”