The recent history of nanocarbon materials has been dominated by the spectacular rise of graphene and its myriad applications [1].in this phase of rapid development, it is easy to overlook the central role played by fullerenes in the evolution of modern nanoscience that followed the pioneering work of Kroto at the University of Sussex, and Curl and Smalley at Rice University [2,3].Fullerene research remains a vibrant field, with much attention focusing on the ability of these bali-like molecules to encapsulate other atoms during vapour-phase synthesis processes [4].The resulting endohedral fullerenes often display unique properties arising from the interactions between the caged atom or cluster of atoms and the carbon framework.More than two decades of research into lanthanide-containing endohedral metallofullerenes,for example, has unearthed an abundance of rich chemistry and physics, notably in the areas of magnetism and electron transport phenomena.Important recent developments include observations of single-molecule magnet behaviour-effectively magnetic hysteresis originating at the level of individual molecules rather than cooperatively across extended domains-in metallofullerenes containing anisotropic lanthanides, particularly dysprosium and terbium [5].The low-symmetry structures of some metallofullerenes can also, in principle, promote bistability in other physical properties, such as the electric dipole moment,therefore forming a theoretical blueprint for ferroelectricity at the single-molecule level.The synthesis of such a molecular electret, a term originating from the fusion of “electricity” with “magnet”, would furnish a potential gateway to innovative new types of nanoscale information storage devices.