High performance γ-Fe ₂ O ₃ decorated rGO–polyaniline core–shell tubes demonstrated exceptional EMI shielding which could be an ultimate choice for future building block material in EMI SE applications.

There is an increased interest in the development of high performance microwave shielding materials against electromagnetic pollution in recent years. Barium ferrite decorated reduced graphene oxide (BaFe₁₂O₁₉@RGO) nanocomposite was synthesized by a high energy ball milling technique and its electromagnetic properties were investigated in the frequency range of 12.4–18 GHz (Ku band). The results showed that barium ferrite (BaFe₁₂O₁₉) nanoparticles with an average particle size of 20–30 nm were well distributed and firmly anchored onto the surface of the reduced graphene oxide sheets. The obtained nanocomposite exhibited a saturation magnetization of 18.1 emu g⁻¹ at room temperature. The presence of BaFe₁₂O₁₉ nanoparticles in the nanocomposite enhances the space charge polarization, natural resonance, multiple scattering and the effective anisotropy energy leading to a high electromagnetic interference shielding effectiveness of 32 dB (∼99.9% attenuation) at a critical thickness of 3 mm. The results suggested that the as-prepared BaFe₁₂O₁₉@RGO nanocomposite showed great potential as an effective candidate for a new type of microwave absorbing material.

The present paper reports the synthesis of a high-performance microwave absorbing material using a simple, cost-effective and scalable method by encapsulating barium strontium titanate (BST) and expanded graphite (EG) in a polyaniline (PANI) matrix. One of the formulations (higher content of BST) shows shielding effectiveness due to absorption of more than 50 dB (>99.9999% attenuation) with minimum reflection loss (≤1 dB) in the Ku-band (12.4–18 GHz) frequency range. Another formulation (higher content of EG) shows a total shielding effectiveness of more than 81 dB with a reflection loss of 10 dB. In order to probe the relationship between the observed shielding response and the electromagnetic attributes, dielectric and permeability parameters have been calculated from the measured scattering parameters (S₁₁, S₂₂, S₁₂, S₂₁) using the Nicolson–Ross–Weir algorithm. The synthesised formulations were characterized thoroughly using XRD, FTIR, TGA, UV, Raman spectroscopy, SEM and HRTEM.