Microcapacitor-Network-Enabled multiple relaxation in ultrathin ferroelectric ceramics for high-performance electromagnetic absorption and intelligent sensing

Ferroelectrics hold great promise for electromagnetic (EM) absorption owing to intrinsic spontaneous polarization. However, high‑efficiency absorption in thin‑layer configurations is severely limited by a single dominant relaxation mechanism. Herein, a microcapacitor-network strategy is developed to synergistically unlock multiple relaxation pathways in ferroelectrics, enabling high‑efficiency EM absorption at ultrathin thicknesses. A “jujube-cake”-architected ferroelectric composite ceramic is presented, featuring an integrated La 0.7 Sr 0.3 MnO 3 -BiFeO 3 -La 0.7 Sr 0.3 MnO 3 (LSMO‑BFO‑LSMO) microcapacitor network. The microcapacitor orchestrates dynamic accumulation‑compensation of interfacial polar charges under EM excitation, thereby generating transient dipoles that significantly intensify interfacial polarization. Meanwhile, BFO ferroelectric domains tailored by interfacial ion diffusion enhance their intrinsic polarization response to EM waves, further reinforcing the microcapacitor-driven interfacial polarization. Empowered by LSMO-tuned continuous microcapacitor networks that amplify this synergy, the optimized BFO/LSMO2 composite delivers robust absorption over an ultrathin 1.2–1.6 mm thickness, with an average RL of -33.9 dB and a minimum RL of -65.8 dB at 1.3 mm. Furthermore, the EM metamaterial designed from this composite exhibits full-band absorption across the entire X-band. Notably, leveraging its pronounced thickness sensitivity, an intelligent pressure-sensing array is validated for rapid battery safety monitoring and response. This study establishes a novel paradigm to high-performance integrated multifunctional EM materials and devices. A microcapacitor-guided paradigm is established in BFO/LSMO ceramics. Synergistic coupling of interfacial charge accumulation with domain-engineered ferroelectricity transcends the single-relaxation bottleneck, enabling high-performance ultrathin electromagnetic absorption and intelligent pressure sensing.