Synthesis and characterization of La-doped Fe3O4-polyaniline magnetic response nanocomposites

Lanathum (La)-doped Fe3O4 magnetic nanoparticles were prepared in aqueous solution at room temperature, then La-doped Fe3O4-polyaniline (PANI) nanocomposites containing a dispersion of La-doped Fe3O4 nanoparticles were synthesized via in-situ polymerization of aniline monomer. The structure and properties of the synthesized samples were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometry (ICPAES), and a vibrating sample magnetometer (VSM). The resulting particles of La-doped Fe3O4 and La-doped Fe3O4-PANI were almost spherical with diameters ranging from 15 to 25 nm and 25 to 85 nm, respectively. The La-doped Fe3O4-PANI composite presented core-shell structures; polyaniline covered the La-doped Fe3O4 completely. The specific saturation magnetization of La-doped Fe3O4-PANI depended on the starting material of La-doped Fe3O4. It increased with increasing amounts of La and Fe3O4 content.