【作者】 顾民； 王素芹； 吴坚； 冯端；

【Author】 Min Gu Suqing Wang Jian Wu Duan Feng National Laboratory of Solid State Microstructures,Nanjing University,Nanjing 210093,P.R.China,

【机构】 南京大学物理系,固体微结构物理实验室；

【摘要】 我们用高压 NO 和 O₂气体对 C₆₀固体进行掺杂,发现两种分子能够扩散进入 C₆₀固体的八面体间隙．室温下,掺 NO 和 O₂的 C₆₀固体样品的¹³C NMR MAS 谱上除了在143．7ppm 处显示出主共振峰以外,还有多个次级共振峰,分别位于主峰低场端,并各自呈等间距排列．次级峰化学位移的大小与 C₆₀周围的客体分子数目成正比,这个现象归因于顺磁性分子与 C₆₀上的¹³C 发生 Fermi 接触作用．接着,我们用变温高分辨¹³C 核磁共振方法分别从210K 到300K 测量不同温度下的¹³C 核磁谱,并分别作各次级峰相对主峰的化学位移与温度倒数的关系（见图1 和图2）,发现满足线性关系,但截距等于一个常数0．13 ppm 或该常数的整数倍．扣除该截距,为一过原点的直线,满足居里定律．根据在高温极限截距不等于零的事实,我们认为主客体分子问存在电荷转移,客体分子上的部份电荷转移到主体 C₆₀分子上,经计算转移量约为0．06e,e 为电子电荷．该结果与从介电法测得结果相符．这个实验结果揭示了极性分子和非极性分子与 C₆₀分子之间都存在微量的电荷转移．更多还原

【Abstract】 Solid C₆₀ was stored in NO and O₂ under high pressure and the gas molecules NO and O₂ were found to diffuse into the octahedral interstitial sites in its fcc crystal lattice.Their ¹³C NMR MAS spectra composed of a primary resonance at 143.7 ppm, accompanied by several minor peaks shifted downfield respectively.The spectra at various temperatures from 210 to 300 K have been measured,and the chemical shifts of the minor peaks referenced to the primary resonance versus 1/T shows straight lines. But,the lines do not go through zero,and their intercepts are equal to 0.13 ppm or its multiple.Due to a non-zero intercept at high-temperature limit,we proposed that there is a charge transfer from NO and O₂ to C₆₀.The quantity of the charge transferred has been calculated,that is about 0.06e（e is electric charge of an electron）.更多还原