Electrostatic coupling driven dielectric enhancement of PZT/BTO multilayer thin films

In this study, PbZr0.52Ti0.48O3/BaTiO3 (PZT/BTO) multilayers with varying layer fractions were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process. The films were characterized by X-ray diffraction and scanning electron microscopy (SEM). The result shows that there exists a dielectric enhancement when the BTO layer fraction x is around 0.5, and at this fraction, the dielectric constant of PZT/BTO is 590 at 100 kHz, which is far more than that of monolithic PZT or BTO films (478 and 284, respectively). The thermodynamic analysis shows that the measured dielectric constant is close to the simulation values when x closes to 0.5, otherwise it better consists with the series connection calculation values. The result indicates that the internal field resulting from the polarization mismatch between two ferroelectric layers contributes to the enhancement of PZT/BTO heterogeneous thin films.

Morphology-induced dielectric enhancement in polymer nanocomposites

The mechanism of the recently discovered enhancement of dielectric properties in dilute polymer-nanoparticle composites is investigated by experiments and computer simulations. We show that the weakening of the hydrogen bonds...