Ferroelectricity and phase transition of halide solid-solution dabcoH(BrxI1−x)

Abstract

The temperature and composition dependence of the ferroelectric and structural phase transition behaviours of hydrogen-bonding molecular relaxor dabcoHX (X = Br, I) were investigated using a halide solid-solution, dabcoH(Br_xI_1−x). A typical relaxor ferroelectric type polarisation-electric field relationship was observed with increases in temperature and Br-content. In addition, the phase transition temperature depends on the composition, and the structure of I-rich solid-solutions changed reversibly back to a hydrogen-bonded hexagonal phase after heating. These results demonstrated the tuning of relaxor ferroelectrics by tuning the ratio of Br and I ions in the one-dimensional dabco-based hydrogen bonding system.