1Shandong Institute of Commerce and Technology, Jinan 250103 2Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 3School of Physics, Shandong University, Jinan 250100
Abstract:The magnetism of highly oriented pyrolytic graphite (HOPG) induced by ion implantation is investigated with electron spin resonance (ESR) spectroscopy and magnetization measurements. The results indicate that the ESR spectra of the HOPG sample correlate with ion species, incident energy and dose of implantation. The correlation of the ESR spectra and magnetism of the HOPG sample with $^{12}$C$^{+}$ ion implantation and H$^{+}$ ion implantation are studied in detail. The ferromagnetism of the HOPG sample is likely related to the asymmetric L1 line, which may be attributed to the interaction between localized defects and itinerant electrons occupied in the 'impurity' band induced by ion implantation.