Preparation and properties of BiFeO3/LDPE nanocomposite

BiFeO₃/LDPE nano-dielectric films of different BiFeO₃ nanoparticles percentages including 0.5%, 1%, and 2% have been successfully prepared using solution-melt blending method in the spiral double pole rheometer. The BiFeO₃/LDPE nanocomposite films were characterized by SEM (scanning electron microscopy), FT-IR (Fourier transform infrared), and XRD (X-ray diffraction). The dielectric properties were tested by the broadband dielectric spectrometer. The experimental results show that BiFeO₃ nanoparticle fillers are homogeneous dispersion in LDPE matrix and the structure of LDPE has not been changed even after doping with BiFeO₃ nanoparticles. It can be seen that dielectric constants of all samples have small extent of variation with frequency from 10⁰ to 10⁵ Hz. Except 0.5 wt.%, dielectric constants are increase with increased of contents of BiFeO₃, and dielectric constant increases up to 2.6 which is increased 16% than that of the pristine LDPE. The dielectric loss of BiFeO₃/LDPE nanocomposites indicate that they have a low dielectric loss in the range of 10⁰ to 10⁵ Hz and the variation of dielectric loss is very small even when contents of BiFeO₃ with 0.5 wt.% and 1 wt.% than pristine LDPE, but a increase was obversed when content of BiFeO₃ nanoparticles reached 2 wt.%. The variation tendency is because of different polarization mechanisms.