Enhanced dielectric and ferroelectric properties in NaTNO/PVDF nanocomposites: a new flexible material for capacitor application

Abstract

Polymer nanocomposites (PNC) showing improved physical properties are emerging as novel functional materials because of their adaptable physical properties for technological applications. We synthesized a new PNC system composed of an insulating ferroelectric poly-vinylidene fluoride (PVDF) host and a high dielectric semiconducting Na_xTi_yNi_1−x−yO (Na and Ti co-doped NiO with x = 0.05, 0.15 and y = 0.02) oxide of variable particle sizes (∼0.5–0.6 μm to ∼80–90 nm) as filler. The PNC system exhibited excellent ferroelectric behavior as well as tensile strength with a low percolation threshold (f_c). The observed large enhancement of room temperature effective dielectric permittivity (ε_eff ∼ 600–750 about 60–75 times that of host PVDF matrix) along with a very low dielectric loss of ≤0.18 at 1 kHz, high dielectric breakdown voltage (>140 kV mm⁻¹) and saturation polarization (∼10 μC cm⁻²) near f_c distinguished these PNC films as suitable candidates for capacitor applications in devices.