Strong ferroelectricity in one-dimensional materials self-assembled by superatomic metal halide clusters

Cluster-assembled materials have long been pursued as they can create some unprecedented and desirable properties. Herein, we assemble a class of one-dimensional (1D) ReNX4 (X = F, Cl, Br and I) and MF5 (M = V, Nb and Ta) nanowires by covalently linking their superatomic clusters. These assembled 1D nanowires exhibit outstanding energetic and dynamic stabilities, and hold sizable spontaneous polarization, low ferroelectric switching barriers and high critical temperature. Their superior ferroelectricity is originated from d0-configuration transition metal ions generated by the hybridization of empty d orbitals of metal atoms and p orbitals of non-metal atoms. These critical insights pave a new avenue to fabricate 1D ferroelectrics toward the development of miniaturized and high-density electronic devices using building blocks as cluster with precise structures and functionalities.