Dielectric and Magnetic Studies of LaFeO3-Polyvinyl Alcohol Composite Films and Their Subsequent Use in Microwave Antennas

Ceramic LaFeO3 (LFO) nanoparticles were synthesized by solid state reaction method. The composite films of this ceramic with polyvinyl alcohol (PVA) were prepared by solution casting method. These composite films were characterized by vibrating sample magnetometer (VSM) and dielectric spectroscopy. From VSM data, these samples show a weak ferromagnetic nature. Further, the various magnetic parameters, like corrosive field (Hc) and saturation magnetization (Ms), were calculated and show a variation with the LFO concentrations in the polymer composites. The dielectric constant decreases with a rise in the applied frequencies. Also, with ceramic doping, a decrease in the dielectric properties was observed. It was observed that the real and imaginary parts of the dielectric constant follow the universal dielectric response. Using these composites as a dielectric substrate, a multi-substrate patch antenna was also designed and fabricated. These fabricated patch antennas resonate at 2626 MHz (for pure RT duroid substrate) and from 2626 to 2639 MHz (for RT duroid/LFO-PVA composite films), therefore indicating a tuning range of approximately 13 MHz. The current properties shown by this material project its possible applications in microwaves.