Domain engineering via AlN compositing in high-entropy ferroelectric ceramics for synergistic electro-thermal regulation

Ferroelectrics enable active thermal management via electric-field switching, but low thermal conductivity and switching ratio limit practical use. Our work demonstrate domain engineering in high-entropy PZT ceramics by AlN compositing via two-step sintering. AlN addition refines the matrix grain size, induces lattice strain, and forms pyrochlore phase at high contents. PFM reveals reduced domain wall density and enlarged domains due to interfacial defect-induced internal bias field.Electrically, P r decreases, while E c and T c exhibit non-monotonic evolution-reflecting a transition from domain wall pinning to leakage and internal field regimes.Thermally, enhanced thermal conductivity competes with reduced switching ratio; a critical composition (x = 0.06) where maximized interfacial phonon scattering yields a localized improvement in thermal switching efficiency. AlN incorporation enables synergistic control of ferroelectric stability and thermal transport through grain refinement, internal field, and domain restructuring. Our work provides fundamental insights into the domain-electrothermal coupling in ferroelectric composites.