Synthesis and characterization of low density polyethylene with multiferroic bismuth ferrite nanocomposite

A novel low density polyethylene (LDPE) with multiferroic bismuth ferrite (BiFeO₃) nano-dielectric was successfully prepared via a solution-melt blending method. The structure, thermal, magnetic, as well as dielectric properties of the nano-dielectric were examined. The microstructures of LDPE/BiFeO₃ were characterized by Fourier transform infrared, X-ray diffraction, and scanning electron microscopy. Microstructural analysis indicated that BiFeO₃ nanoparticles were well dispersed in the LDPE matrix and the structure of LDPE was unchanged even after doping with BiFeO₃ nanoparticles. The differential scanning calorimetry data of the thermal properties revealed that melting temperature has decreased and crystallinity has increased. The reason was that amount of nucleation agents was increased and crystal propagation rate was changed. The corresponding magnetic and dielectric properties were measured using vibrating sample magnetometer and broadband dielectric spectrometer. The results showed that the magnetization behaviour of diamagnetic LDPE was transformed due to the antiferromagnetism of BiFeO₃. In addition, the dielectric permittivity and loss of LDPE/BiFeO₃ increased with increasing BiFeO₃ filler concentrations in the LDPE matrix due to different response mechanisms.