【摘要】 通过化学气相沉积法直接在SiO2衬底上750℃裂解乙炔制备出直径约为3～5μm,具有层状结构并含有大量缺陷的相互连接的石墨基碳微米球。结果表明:碳微米球除了表现出通常的抗磁性外,还表现出由于本征缺陷导致的未配对自旋而引起的顺磁性;这些缺陷提供自旋为1/2的磁矩;通过布里渊函数拟合得到,大约平均每1 000个碳原子贡献出1.1μB的未配对自旋磁矩;1/xp-T曲线表明这些未配对自旋之间并没有相互作用,样品表现出典型的居里型顺磁。更多还原

【Abstract】 Interconnected carbon micro-spheres(CMSs) with diameters in the range of 3~5 μm were synthesized by acetylene pyrolysis at 750 ℃ on a SiO2 substrate.The CMSs have a graphitic structure with many intrinsic defects.Results indicate that the CMSs show both diamagnetic and paramagnetic behavior.Intrinsic defects have magnetic moments with spin 1/2.Approximately every 1,000 carbon atoms contribute 1.1 μB unpaired spins.The unpaired spins have no interactions with each other and show typical Curie-like paramagnetic behavior.更多还原