Investigation of microwave absorption property of the core-shell structured Li sub(0.4)Mg sub(0.6)Fe sub(2)O sub(4)/TiO sub(2) nanocomposite in X-band region

Initially, we have synthesized a magnetic spinel-type ferrite, Li sub(0.4)Mg sub(0.6)Fe sub(2)O sub(4) (LMF) by a simple chemical coprecipitation method. The LMF particles of different sizes were formed, and the most populated size range is 45-75 nm. Further, the LMF was coated by titanium di-oxide (TiO sub(2)) via the sol-gel process, and examined the microwave absorption property of TiO sub(2) coated LMF (TiMF) in the X-band region. The formation of both LMF and TiMF was supported by analysing the materials through different analytical techniques such as X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared (FTIR) spectroscopy. The core-shell morphology of TiMF was confirmed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. The result indicates that the average shell thickness is around 40-50 nm. The optical and magnetic property was studied by UV-VIS spectroscopy and SQUID analysis. TiMF showed excellent microwave absorption property under the thermoplastic polyurethane (TPU) matrix. The maximum reflection loss (-41.6 dB) was measured with the help of Vector Network Analyzer, and the mechanism of absorption was explained by considering the relative complex permittivity and permeability of the prepared materials. The matching of both the dielectric loss (initiated by TiO sub(2)) and magnetic loss (initiated by LMF) is the main reason for remarkable microwave absorption property of TiMF.