1999 年 48 巻 6Appendix 号 p. 110-115
In this study, we examined the correlation among the crystal structure, the unpaired electron, and the magnetism of carbon fine particles. From the result of X-ray diffraction, it is determined that the saturation magnetization of the carbon fine particles is influenced by degree of crystallinity, when the degree of crystallinity is 3.62%. The saturation magnetization is 8.5×10-7Wb·m/kg. The saturation magnetization of carbon fine particles increases with decreasing grain size, and the grain size of the carbon fine particles having the highest Ms of 8.5×10-7Wb·m/kg is 19nm. From the ESR spectrum, the g-factor of the carbon fine particles is found to be 2.0023. The magnetism of carbon fine particles may be due to the electron spin. Electron spin density of the carbon fine particles is 1.6×1022kg-1 and it is observed that the electron spin density increases by 1.5 times as compared with graphite. From the temperature dependence of ESR, it is found that the linewidth of the ESR increased with decreasing temperature, and the spin-spin relation time T2 decreased with decreasing temperature.
