Enhancing microwave absorption of double perovskite La2CoMnO6 via nitrogen-doped carbon interface engineering

The growing concern over electromagnetic pollution has intensified attention on the double perovskite La 2 CoMnO 6 (LCMO) microwave absorbing material with high dielectric constant. However, its practical microwave absorption is constrained by inherent impedance mismatch and attenuation capability. To overcome these limitations, we propose a simple interface engineering strategy based on a polydopamine-derived nitrogen-doped carbon (NC) layer on LCMO surface. The NC layer not only enhances conductive loss by constructing a conductive network but also induces the generation of oxygen vacancies to enrich polarization centers, and induces the exchange coupling of Mn 4 + , Mn 3+ , Co 3+ , Co 2+ to increase magnetic loss. The controlled thickness of the NC layer makes it possible to construct heterointerfaces with good impedance matching. The optimal NC layer on LCMO (LCMO@NC‑5) achieved a minimum reflection loss (RL min ) of −56.15 dB and an effective absorption bandwidth (EAB) of 3.55 GHz at a matched thickness of 3.8 mm. This study confirms that precise interface engineering using ultrathin NC coatings provides an effective route and design strategy to unleash the potential of perovskite-based absorbing materials.