Tuning the magnetic properties of beryllium chains
Résumé
In this work we explore the effect of confining beryllium chains inside carbon nanotubes. Linear Be n systems are characterized by two states originating from the presence of edge orbitals localized at the chain extremities. The two spins occupying these orbitals are, in gas phase, an-tiferromagnetically coupled, with the magnetic coupling J decaying exponentially as a function of the increasing length of the chain. When inserted into narrow carbon nanotubes, the linear geometry is found to be more stable than the more compact cluster conformation favored for the isolated case: the lack of space inside the cavity prevents the chain to fold. Most importantly, the presence of the surrounding nanotube does not only preserve the linear structure of Be n , but it affects its magnetic properties too. In particular it was found that the magnetic coupling between the ground and the first excited state can be modulated according to the nanotube diameter as well as chain length, and our calculations suggest a possible direct relationship between these parameters and J. This behavior can be exploited to engineer a composite Be n @CNT system with a magnetic coupling tuned by construction, with interesting potential applications.
Domaines
Chimie théorique et/ou physique
Origine : Fichiers produits par l'(les) auteur(s)
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