Change of magnetic behaviour of nitrogenated carbon nanotubes on chlorination/oxidation

Abstract

The magnetic effects of chlorine and oxygen functionalised NCNTs have been studied. The diamagnetic behaviour of non-functionalised NCNTs changes to paramagnetic behaviour on Cl-functionalisation; on O-functionalisation NCNTs become ferromagnetic. A prominent cusp-like behaviour is observed at around ≈45 K in M FC and M ZFC measurements, further confirming the ferromagnetic behaviour of O-functionalised NCNTs; but Cl-functionalised NCNTs do not shows any cusp-like behaviour indicating formation of paramagnetic behaviour. The change of magnetic behaviour occurs owing to formation of different bonding with carbon/nitrogen and/or Fe-catalyst atoms that is verified with theoretical calculation. The initial computational results show that the differential bonding patterns of the Cl-functionalised and the O-functionalised NCNTs are the main cause for the different magnetic behaviour in these systems.