Large room-temperature magnetodielectric effect in polyvinylidene fluoride-trifluoroethylene/La0.7Sr0.3MnO3 (0-3) nanocomposite thin films

We observe large room-temperature magnetodielectric effect (nearly 12% suppression of dielectric constant under ∼20 kOe field) as well as its remarkable field-driven switch – from positive to negative – in polyvinylidene fluoride-trifluoroethylene/La0.7Sr0.3MnO3 (PVDF-TrFE/LSMO) thin films (0–3 connectivity) containing 7.5 volume% LSMO. The magnetodielectric effect is mapped with the volume fraction of the LSMO nanoparticle across 5-20 volume%. It reveals a close correlation among the LSMO nanoparticles volume fraction, their distribution pattern within the PVDF-TrFE matrix, uniformity in the magnetic domain size (imaged by magnetic force microscopy), and the magnetodielectric effect. The observed 20% jump in the intrinsic bulk capacitance at a critical magnetic field HC ∼10 kOe can be exploited to develop smart nanoscale magnetoelectric devices.