First-Principles Calculations of Magnetic Moment Modulation of 3d Transition Metal Atoms Encapsulated in C60/C70 Cages on Si(100) Surfaces: Implications for Spintronic Devices

Manipulations of single atoms or molecules at the nanoscale have significant potential for applications in microelectronic devices. Magnetic materials are widely used in the fields of information storage and spintronics. Here, we study the controllability of the moment of 3d transition metal (TM) atoms adsorbed on the Si(100) surface using first-principles calculations. The TM atoms lose their magnetic moment due to hybridization with the substrate. If the TM atoms are encapsulated in a C-60 or C-70 cage, the magnetic moments can be preserved due to the shielding effect. The cages can isolate the atoms from direct hybridization with the substrate. Interestingly, we found that C-70 has a stronger protecting effect, even with an impurity level located above the Fermi level. Based on the Anderson impurity model, this exotic phenomenon can be attributed to the presence of linear dispersion around the Fermi level. This work provides an experimental strategy for modulating the magnetic moments in nanoscale systems, which is also beneficial for the design of silicon-based spintronic devices.

Automated summary

The controllability of magnetic moments of 3d transition metal atoms adsorbed on the Si(100) surface was studied using first-principles calculations. It was found that encapsulating the TM atoms in C-60 or C-70 cages can preserve their magnetic moments, isolating them from direct hybridization with the substrate. The presence of linear dispersion around the Fermi level was attributed to the stronger protecting effect of C-70.