Magnetic anisotropy of dysprosium encapsulated metallofullerene molecules: a theoretical study

A series of metallofullerene single-ion magnets embedded with [DyO]⁺ and [DyO₂]^- fragments were designed to probe the magnetic anisotropies and magnetic relaxation mechanisms using complete-active-space self-consistent field (CASSCF) calculations. CASSCF calculations showed that fullerenes with different diameters exert marginally varying influences on both the quantum tunneling of magnetization and energy level splitting, ultimately causing changes in energy barriers. Notably, [DyO]⁺ encapsulated in the fullerenes of C₈₀ shows the best behavior. For [DyO₂]^-, however, the largest C₁₀₀ is preferable due to the presence of the largest O-Dy-O angle. If the O-Dy-O angle is increased to 180°, the energy barrier of [DyO₂@C₁₀₀]^- would reach the highest value up to 4075.9 cm^-1.