Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source

TL;DR

This paper investigates the use of gas-mixing techniques in an ECR ion source to reduce fullerene destruction, demonstrating that helium mixing effectively preserves fullerene molecules during plasma processing.

Contribution

It introduces a gas-mixing method, particularly with helium, to improve the yield of endohedral fullerenes in ECR plasma sources, addressing a key challenge in fullerene synthesis.

Findings

Helium gas mixing reduces fullerene dissociation in plasma.

Mass spectra show higher intact fullerene ion yields with helium.

Helium is more effective than Ar or Xe in preserving fullerenes.

Abstract

A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.