Carbon-coated YC2 nanocapsules synthesized by arc-discharge in methane

Carbon-coated YC2 nanocapsules were prepared by arc-discharging bulk yttrium in methane. The core/ shell structure was obtained, where a polyhedral crystalline YC2 core was coated by defective graphite shell with size of 1–3 nm. The hydrolyzing of the zero-dimensional superconductors YC2 was controlled by the shell. The magnetic properties of the carbon-coated YC2 nanocapsules show that the dimensional effect has a very small influence on its superconducting transition temperature. The Raman spectrum of the carbon-coated YC2 nanocapsules shows that the shell is defective graphite and also suggests that the aberrance structure of the carbon shell is related to the zone-edge vibration of the YC2 core.