Design tunable materials: Ferroelectric-antiferroelectric composite with core-shell structure

Permittivity, tunability, and ferroelectric properties can be tailored to meet specific requirements for applications by combining ferroelectric (BaTiO3-BT) and antiferroelectric (La0.04Pb0.96Ti0.1Zr0.9O3-PLZT) and by exploiting interdiffusion and grain size effects at nanoscale. The dielectric properties, dc-tunability, and P(E) loops of ferroelectric-antiferroelectric nanostructured composites produced from mechanically mixed powders (PLZT-BT) and from core-shell particles (PLZT@BT) were comparatively analyzed. Interdiffusion accompanied by local composition gradients occurred during sintering of PLZT@BT composites and caused a thermally stable permittivity. Permittivity was reduced below 1000 in both cases (900 for PLZT-BT and 290 for PLZT@BT), while preserving tunability to 1.2–1.4 (E = 40 kV/cm), with a linear field dependence.