Cluster formation of endohedral metallofullerenes with Y, Gd, and Ho in a solution and on a solid surface

The formation of endohedral metallofullerene clusters with Y, Gd, and Ho in an $N,N$-dimethylformamide solution and on a mica substrate surface has been investigated using static and dynamic light scattering and atomic force microscopy, respectively. It has been found that the size distribution of the clusters depends on the concentration of endohedral metallofullerenes and on the exposure time of the solution. It has been shown that the clusters are resistant to high temperatures and ultrasound effects. The concentration of endohedral metallofullerenes at which only single clusters are formed in the solutions has been determined. It has been established that an increase in the concentration of endohedral metallofullerenes leads to the agglomeration of single clusters. The fractal dimension has been estimated, and the zeta potential of endohedral metallofullerene clusters has been measured.