A strategy for modulation of permittivity in manganese doping to induce lattice distortion

Abstract The modulation of electromagnetic parameters is crucial for tuning the dielectric and magnetic properties of materials. In this work, the concentration of oxygen vacancies ( V _O ) and the degree of lattice distortion in spinel oxides were successfully regulated by implementing a heteroatom doping strategy, which enhanced the structural stability as well as the optimization of the permittivity. However, the description of the polarization mechanisms in spinel structures is currently unclear. Therefore, carbon cloth (CC) surface was constructed with modified spinel structure to form nanosheet arrays (C@NMC). Localized electronic reconfiguration and altered spinel configurations were achieved by modulating manganese (Mn) substitution at specific metal sites. The lattice distortion activated dipole polarization, which increased the permittivity of the CC material to twice its original value. As a result, Mn–doped C@NMC samples (C@NMC–0.2) demonstrate a reflection loss (RL) of −63.40 dB (2.06 mm) and an effective absorption bandwidth (EAB) of 4.80 GHz. This work achieves precise regulation of dielectric properties through atomic–level defect engineering, while establishing a synergistic model between structural stability and polarization paths at the experimental level. This research provides a new perspective for an in–depth understanding of the electromagnetic loss mechanism of spinel oxides. image