In situ synthesis and characterization of LiNi0.5La0.08Fe1.92O4–polyaniline core–shell nanocomposites

Core–shell-structured LiNi0.5La0.08Fe1.92O4–polyaniline (PANI) nanocomposites with magnetic behavior were synthesized by in situ polymerization of aniline in the presence of LiNi0.5La0.08Fe1.92O4 nanoparticles. The structure, morphology and magnetic properties of samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV–vis absorption, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) technique. The results of spectroanalysis indicated that there was interaction between PANI chains and ferrite particles. TEM study showed that LiNi0.5La0.08Fe1.92O4–PANI nanocomposites presented a core–shell structure with a magnetic core of 30–50 nm diameter and an amorphous shell of 10–20 nm thickness. The nanocomposites under applied magnetic field exhibited the hysteresis loops of the ferromagnetic nature. The saturation magnetization and coercivity of nanocomposites decreased with decreasing content of LiNi0.5La0.08Fe1.92O4. The polymerization mechanism and bonding interaction in the nanocomposites have been discussed.