Magnetic Transition in the Polymerized Fullerene Matrix

Abstract

A mechanism of the ferromagnetism in the polymerized fullerene phase is proposed. We show that non‐magnetic defects and impurities give rise to a magnetic transition in the polymerized fullerene matrix. In our model, C₆₀ molecules acquire spin and charge and become magnetically active due to the spin and charge transfer from non‐magnetic dopants. The interaction between magnetic moments of the arising paramagnetic species (C₆₀ ^± ions or C₆₀ R radical adducts) dispersed in the polymeric network is inspected by using ab initio Hartree‐Fock and B3LYP hybrid density functional methods. It is revealed that the interaction is ferromagnetic and large enough for creating the high‐T _c magnetism.

Keywords:

• Polymerized fullerenes
• ferromagnetism
• ab initio calculations
• spin and charge transfer
• paramagnetic impurities
• hydrogen
• fluorine
• hydroxyl group

Acknowledgments

The work is supported by the RFBR (Projects 03‐02‐17557, 05‐02‐17779), Swedish Research Council and Royal Swedish Academy of Sciences, European FP6 project “Ferrocarbon.”