Enhancement of Electromagnetic Wave Attenuation through Polarization Loss Induced by Hybridization of Rare-Earth 4f and Mo-4d Orbitals in Liquid Plasma

The incorporation of large-sized rare earth (RE) elements with high coordination characteristics into transition metal dichalcogenide (TMD) absorbers while preserving a high 1T phase content during post-processing poses a significant challenge. To address this, a novel strategy involving the confinement of RE elements within the 1T-MoS₂ lattice via liquid plasma assistance, is proposed. This approach effectively mitigates the environmental impact on the 1T phase of MoS₂, yielding a remarkable 1T phase content of 82.69% for Ce20-D7 (20 wt.% Cerium trinitrate and 7 kV applied voltage). Combining experimental and theoretical investigations reveals that the multi-orbital characteristics of RE elements facilitate hybridization between the RE-4f and Mo-4d orbitals on the MoS₂ surface, leading to the occupation of weakly bound electrons in bonding orbitals with short-distance motion, enhanced inter-orbital electron-electron interactions, and induced polarization loss. Notably, the results demonstrate that the Pr15-D7 sample (15 wt.% praseodymium nitrate and 7 kV applied voltage) exhibits an effective absorption bandwidth (EAB) of 7.12 GHz at 2.6 mm, with a minimum reflection loss of -52.02 dB while the Ce20-D7 sample achieves an EAB of 6.96 GHz at 2.7 mm. These findings provide valuable insights for the rational design and development of high-performance TMD absorbers leveraging RE-modified materials.