A single molecule magnet (SMM) can maintain its magnetization direction over a long period of time [1,2]. It consists in a low number of atoms that facilitates the understanding and control of the ground state, which is essential in future applications such as high-density information storage or quantum computers [3,4]. Endohedral fullerenes realize robust, nanometer sized, and chemically protected magnetic clusters that are not found as free species in nature. Here we demonstrate how adding one, two, or three dysprosium atoms to the carbon cage results in three distinct magnetic ground states. The significantly different hysteresis curves demonstrate the decisive influence of the number of magnetic moments and their interactions. At zero field the comparison relates tunneling of the magnetization, with remanence, and frustration. The ground state of the tridysprosium species turns out to be one of the simplest realizations of a frustrated, ferromagnetically coupled magnetic system.
@article{arxiv.1310.5040,
title = {Tunneling, Remanence, and Frustration in Dysprosium based Endohedral Single Molecule Magnets},
author = {Rasmus Westerström and Jan Dreiser and Cinthia Piamonteze and Matthias Muntwiler and Stephen Weyeneth and Karl Krämer and Shi-Xia Liu and Silvio Decurtins and Alexey Popov and Shangfeng Yang and Lothar Dunsch and Thomas Greber},
journal= {arXiv preprint arXiv:1310.5040},
year = {2014}
}