Preparation of polyimide/BaTiO3?nanocrystal hybrid thin films and their dielectric property
High dielectric constant is highly desirable in capacitors and memory devices. In this work, oleic acid (OA)?capped BaTiO3 nanocrystals were synthesized by a two?phase approach. Polyimide (PI)/BaTiO3?nanocrystal composite thin films with high dielectric constant have been successfully fabricated. The morphologies and dielectric properties of the hybrid films were exploited. The results showed that BaTiO3 nanocrystals can be uniformly dispersed in the PI thin films owing to the surface modification of OA?capped BaTiO3 nanocrystals. It was found that the dielectric constant of composite film varies with the volume fraction of BaTiO3 nanocrystals and sintering temperatures and reaches a maximum value of 44.1, which is around 13 times higher than that of pristine PI thin film (3.2). These results demonstrated that PI/BaTiO3?nanocrystal composite films have considerable application potential in microelectronic fields.