Unraveling the Contributions to Spin-Lattice Relaxation in Kramers Single-Molecule Magnets.
Sourav MondalAlessandro LunghiPublished in: Journal of the American Chemical Society (2022)
The study of how spin interacts with lattice vibrations and relaxes to equilibrium provides unique insights into its chemical environment and the relation between electronic structure and molecular composition. Despite its importance for several disciplines, ranging from magnetic resonance to quantum technologies, a convincing interpretation of spin dynamics in crystals of magnetic molecules is still lacking due to the challenging experimental determination of the correct spin relaxation mechanism. We apply ab initio spin dynamics to a series of 12 coordination complexes of Co 2+ and Dy 3+ ions selected among ∼240 compounds that largely cover the literature on single-molecule magnets and well represent different regimes of spin relaxation. Simulations reveal that the Orbach spin relaxation rate of known compounds mostly depends on the ions' zero-field splitting and little on the details of molecular vibrations. Raman relaxation is instead found to be also significantly affected by the features of low-energy phonons. These results provide a complete understanding of the factors limiting spin lifetime in single-molecule magnets and revisit years of experimental investigations by making it possible to transparently distinguish Orbach and Raman relaxation mechanisms.
Keyphrases
- single molecule
- living cells
- atomic force microscopy
- magnetic resonance
- systematic review
- room temperature
- magnetic resonance imaging
- computed tomography
- single cell
- molecularly imprinted
- gene expression
- molecular dynamics simulations
- simultaneous determination
- solid phase extraction
- transition metal
- liquid chromatography