Microwave absorbing properties of the core-shell structured LaFeO3-NiO nanocomposites

This work investigates the microwave (MW) absorbing properties of the ferrite based core-shell (x)LaFeO3 - (100-x)NiO; x = 0, 25, 50, 75, & 100 nanocomposites. X-ray diffraction (XRD) patterns confirm the formation of phase pure composites. The energy dispersive spectroscopy (EDS) analysis was employed to examine the chemical composition and the elemental mapping of the prepared samples. The complex permittivity (epsilon* = epsilon '-i epsilon '') and permeability (mu* = mu '-i mu '') measurements were carried out on a vector network analyser (VNA) over a frequency range of 2-18 GHz. The reflection loss (R-L)/MW absorption of the samples were calculated using the transmission line theory. 50LFO/50NiO (x = 50) nanocomposite sample displays a strong MW absorption of about 99.92 % (minimum reflection loss = -31.90 dB) at 13.4 GHz frequency. The frequency bandwidth for a reflection loss < -10 dB of similar to 6 GHz is observed at a sample thickness of 2.3 mm in 50LFO/50NiO sample. The co-existence of broad-bandwidth and strong MW absorption in the 50 LFO/50NiO sample makes it a promising material for the designing of futuristic MW absorbing devices.