A valuable strategy to improve ferroelectric performance significantly via metallic ion doping in the lattice nodes of metal–organic frameworks

Abstract

Metal–organic frameworks (MOFs) with polar space groups in crystallography represent a class of potential molecular-based ferroelectrics; however, the rational design and enhancement of the performance of MOF-based ferroelectrics is a great challenge. In this work, a series of mixed-metal MOFs deriving from Mg²⁺ ions doped into the lattice nodes of the parent-MOF (Ni-MOF) are synthesized by an in situ solvothermal method. Taking advantage of Mg²⁺ ions doped in the Ni-MOF, the doped-MOFs (Mg/Ni-MOFs) appear to have a significant lattice distortion and noteworthy dipole asymmetry in the crystals. It is found that the obtained doped-MOFs show a significant enhancement of ferroelectricity compared with that of the parent-MOF. This study opens up a new landscape to explore possibilities for controlling ferroelectric performance in MOF-based ferroelectrics.