Theoretical and Experimental Observations on Empowered EMI Shielding of Rare Earth Ion Infused α-MnO 2 Nano-rods

Abstract

Abstract In this communication, for the first time rare earth elements like Gd3+ and Er3+ ions are impregnated into the α-MnO2 tunneled structure involving the modified chemical synthesis route followed by hydrothermal technique. X-ray diffraction patterns and Raman spectroscopy confirm the proper phase formation without any impurity. A theoretical in-depth DFT study for the electronic bands and variation of density of states with the infusion of rare earth elements into the host structure confirms the experimental findings and depicts the suitability of the material towards the EMI shielding application. The novel synthesis technique helps to achieve uniform nanorod formation with a high specific surface area. Doping-induced defects, high surface-to-volume ratio, Maxwell-Wagner–Siller interfacial polarization, etc lead to achieving high dielectric response with moderate tangent loss at frequency range 40Hz to 1MHz. Temperature-dependent dielectric behavior indicates the paramagnetic to ferromagnetic transition at 120 \(℃\) and 70 \(℃\) for the Gd- and Er-doped α-MnO2 samples respectively. The electromagnetic interference (EMI) shielding effectiveness (SE) has achieved a maximum of − 43 dB at 15.3 GHz and − 46 dB at 15.3 GHz for Gd- and Er-doped α-MnO2 thin layer of thickness ∼600 µm respectively. Higher dipolar polarization, loss tangent, conductive pathways, and defects inside the crystal lead to attaining a high EMI shielding efficiency. This result reveals > 99.999% EMI SE against the hazardous electromagnetic waves in the microwave/GHz frequency region.