摘要
An attempt was made to prepare nanographite with uniform size by pyrolysis of 4-methyl pyridine (MPy), which is the structure-directing agent for the formation of GaPO4-LTA single crystals, in the GaPO4-LTA frame-work at 760 ℃. The as-prepared nanographite has been examined by Raman spectroscopy, transmission electron microscopy (TEM), electron spin resonance (ESR) and magnetization characterizations. The TEM image shows that the size of individual nanographite particles is about 7 nm, and it is proved that there are spins of sp2-type (π-type) radical electrons localized on the zigzag edge sites of the nanographite. The magnetic susceptibility of the nanographite shows crossover from a high-temperature diamagnetic to a low-temperature paramagnetic behavior, in good agreement with the theoretical expectation.
An attempt was made to prepare nanographite with uniform size by pyrolysis of 4-methyl pyridine (MPy), which is the structure-directing agent for the formation of GaPO4-LTA single crystals, in the GaPO4-LTA frame-work at 760 ℃. The as-prepared nanographite has been examined by Raman spectroscopy, transmission electron microscopy (TEM), electron spin resonance (ESR) and magnetization characterizations. The TEM image shows that the size of individual nanographite particles is about 7 nm, and it is proved that there are spins of sp2-type (π-type) radical electrons localized on the zigzag edge sites of the nanographite. The magnetic susceptibility of the nanographite shows crossover from a high-temperature diamagnetic to a low-temperature paramagnetic behavior, in good agreement with the theoretical expectation.
基金
Project supported by the National Natural Science Foundation of China (No. 20331010) and the Education Ministry of China.
