Position-dependent spin-dynamics in cobalt-substituted graphene nanoflakes
Yiming Zhang1,2,3, Shuai Xu2,4,5, Jing Liu6
1School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Physical Chemistry Chemical Physics : PCCP
|August 7, 2025
Summary
Placing cobalt atoms near zigzag edges of graphene nanoflakes (Co/GNF) significantly speeds up spin-flip processes. This atomic positioning enhances spin dynamics for next-generation spintronics.
Area of Science:
- Computational materials science
- Quantum chemistry
- Spintronics
Background:
- Ultrafast spin dynamics are crucial for spintronic devices.
- Graphene nanoflakes (GNFs) offer tunable electronic properties.
- Substitutional doping with magnetic atoms, like cobalt (Co), can modify spin behavior.
Purpose of the Study:
- To investigate the influence of cobalt dopant position on ultrafast spin dynamics in rhombic graphene nanoflakes (Co/GNF).
- To understand the mechanisms behind position-dependent spin-flip efficiency.
- To establish design principles for optimizing spin dynamics in graphene-based spintronic systems.
Main Methods:
- Ab initio quantum chemical calculations were employed.
- Systematic investigation of spin-flip processes in Co/GNF structures.
- Analysis of the impact of dopant placement (edge vs. central) on spin dynamics.
Main Results:
- Cobalt dopants near zigzag boundaries (N-type) enable spin-flip processes ~40% faster (0.55 ps) than central doping.
- Boundary-mediated exchange interactions enhance spin-flip efficiency via hybridized orbitals.
- Central doping results in slower spin-flip processes with reduced interaction with edge states.
Conclusions:
- Zigzag edge geometry critically governs spin dynamics in Co/GNF systems.
- Atomic-scale positioning of dopants is a viable strategy for enhancing spintronic device performance.
- The findings are extendable to other nanostructures and pave the way for next-generation spintronics.
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