Intriguing electric field effect on magnetic spin couplings in dielectron clathrate hydrates

Clathrate hydrates have appeared as promising icy materials as the radical, high-spin molecule, and even electron clathrate hydrates are found. In particular, dielectron clathrate hydrates are expected to develop as structural units for a novel class of icy magnetic materials because of not only possible spin coupling interaction, but also very sensitive response to electric field of the loosely bound electrons. However, electric field responses concerning the magnetic properties of such hydrates have not been reported so far. In this work, three representative dielectron clathrate hydrate model clusters (e₂@4⁶6⁸BB, e₂@5¹²6²BB, and e₂@4⁶6⁸AB) were considered for the exploration of their magnetic spin coupling properties, electron distributions, and energy responses to applied electric field. The results calculated at the density functional theory level show that the energies and electron spin coupling properties of these dielectron clathrate hydrate clusters are quite sensitive to applied electric field, presenting intriguing variations. Most importantly, applied electric field can regulate the strength of spin coupling between two trapped electrons, and even could realize the magnetic interconversion of such dielectron cluster structures between antiferromagnetic and paramagnetic or diamagnetic characteristics. Clearly, the intriguing variations should be attributed to the diffuse character, special mobility and polarizable properties of such trapped electrons, and especially the susceptible redistributions of two electrons (including the electron cloud shape and distance between two electron centers) to the electric field. This work opens up the possibility of designing novel icy magnetic materials with sensitive electric field responses of the magnetic properties.