Facile synthesis of hierarchical A-site cation deficiency perovskite LaxFeO3-y/RGO for high efficiency microwave absorption

Wafer biscuit structure like hierarchical A-site cation deficiency perovskite at carbon and RGO hybrid composites-LaxFeO3-y/RGO are fabricated by a simple one-pot route. The quantitative ratios of A-site cation deficiency are designed, and was represented by x = 1.0, 0.8, 0.6, 0.4 and 0.2, respectively. Besides the morphology and phase structure, but the chemical composition, especially the O vacancy induced by the deficiency, was also studied by X-ray photoelectron spectroscopy (XPS) data. The electromagnetic microwave absorption capabilities of these composites were further studied. Accompanying with the appearance of A-site cation deficiency, the reflection loss (RL) was optimized instinctively. The minimum RL of La0.8FeO3-y/RGO reaches 36.23 dB with an effective band (RL <= 10dB) width of 3.92 GHz from 11.68 to 15.60 GHz at the matching thickness 2.00 mm, which was demonstrated the domain role of dielectric loss ascribed to the polarization of dipoles between O vacancy and Fe4+. When the deficiency increased, the band widths reached 4.72 GHz with the synergistic effect of magnetic and dielectric phase.