Enhanced microwave absorption in GaFeO3 coated CoFe2O4 nano-hollowsphere

As a multiferroic material with substantial magnetoelectric coupling, gallium ferrite (GaFeO3, GFO) has been intensively studied in recent years. Cobalt ferrite (CoFe2O4, CFO) nano-hollowsphere (NHS), on the other hand, is found to be an efficient material for electromagnetic (EM) wave absorption. In this work, a composite consisting of magnetostrictive CFO NHS coated with GFO nanoparticles [(1−x)CoFe2O4 – xGaFeO3, for x = 0.0, 0.9, 0.7, 0.5, 0.3, and 1.0] is prepared as an effective strategy to develop highly efficient microwave material. The EM wave absorption properties of the samples are thoroughly investigated across a widely used frequency range of 1–20 GHz. Remarkable performance of the x = 0.7 composite is evident by its effective bandwidth of approximately 3 GHz and a minimum reflection loss of approximately −63.26 dB. Moreover, the excellent impedance matching, with |Zin/Z0| ≅ 1.00, observed in the aforementioned composite, satisfies well with the required characteristics for a superior microwave absorber. Therefore, a core–shell nanostructure consisting of CFO NHS as core and GFO with optimized shell thickness can be used successfully in microwave devices.