Multifunctional Fe₃O₄/ZnO Nanocomposites with Magnetic and Optical Properties

Multifunctional Fe₃O₄/ZnO nanocomposites were successfully synthesized through two-step solution-based methods. Fe₃O₄ nanoparticles were used as seeds for the deposit and growth of ZnO nanocrystals. Transmission electron microscopy (TEM) images, X-ray diffraction (XRD) patterns, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were employed to observe the morphology, size, structure, and crystalline phase of the nanocomposites and confirm their chemical composition. The results of magnetization curves, resonant Raman scattering, and photoluminescence spectra revealed that the nanocomposites simultaneously possessed the superparamagnetism of Fe₃O₄ and the multiphonon resonant Raman scattering and photoluminescence (PL) properties of ZnO. Compared with that of pure Fe₃O₄, the saturation magnetization of the Fe₃O₄ component within the nanocomposites was enhanced. The Raman spectroscopic fingerprint of ZnO component was preserved, and the fluorescent background was efficiently reduced. The interfacial effect was found to play an important role in modulating or improving the properties of the nanocomposites.