Accessory ligand strategies for hexacyanometallate networks deriving perovskite polycrystalline electromagnetic absorbents

The controllable adjustment of electromagnetic (EM) properties for high-efficiency EM absorbents are indispensable, nonetheless, rare in crystals engineering regulation. Herein, for the first time, regulated amount of sodium citrate was employed as accessory ligand of cobalt cation in aqueous solution to kinetically assist the controllable fabrication of Prussian blue analogs (PBAs) and corresponding lanthanide perovskite hybrid CoFe alloy polycrystals. Especially, the multi-phase features were analyzed based on Rietveld refinement of XRD patterns, illustrating the existence of distortions, defects and heterogeneous interfaces in resultant polycrystals. Benefited to the dielectric and magnetic adjustment, polycrystalline absorbents achieved excellent impedance matching and EM attenuation, as the minimum reflection loss of CoFe/LaFeO₃ and CoFe/LaFeO₃/La₂O₃ reached -44.13 and -33.95 dB, ranking broadest effective bands up to 4.88 and 3.36 GHz. The validity of the strategy provided a novel sight into the controllable fabrication of high-performance magnetic semiconductor polycrystalline devices.