Triphasic Inter-Dimensional WS2/Magnetic Lithium Iron Oxide Nanocomposite for Electromagnetic Interference Shielding

The widespread use of wireless devices and telecommunication networks has given rise to electromagnetic interference (EMI) pollution that can cause data corruption, critical device failure, and detrimental effects on wildlife and human health. Developing EMI shielding materials can block these harmful electromagnetic waves. This study explores inter-dimensional composite systems composed of dielectric and magnetic phases (WS2/biphasic lithium iron oxide) for EMI shielding applications. WS2 is a 2D material with unique dielectric properties and flake-like morphology that enhances surface effects. In contrast, biphasic magnetic lithium iron oxide nanocomposites have grain-like morphology with greater magnetic losses. The formation of interfaces between these two phases with different morphologies and dimensionalities leads to enhanced interfacial polarization loss. This work demonstrates that by carefully controlling the weight percentage of the two phases, and thereby the interfaces, the EMI shielding properties can be significantly enhanced. An optimum phase composition is determined that exhibits maximum shielding efficiency (SET ≈55.6 dB at 12.4 GHz) with high absorption shielding (SEA ≈48.8 dB at 12.4 GHz), and an absorption coefficient more than 100% higher than either end member. The studied nanocomposites, with their tunable absorption and reflection capabilities, are suitable for a wide range of EMI shielding applications.