Fabrication of Nanodielectric BaTiO3 Composites Exhibiting Stable Capacitor Functions in the High Frequency (>100 MHz) Through Interfacial Polarization Interactions

We report fabrication of two different nanodielectric composites comprising a uniform blend of inorganic-organic and inorganic-inorganic dielectric materials by a simple and single-step method of electron-beam-assisted vapor-phase codeposition. The fabrication method allowed ambient temperature (similar to 35 degrees C) generation of well-crystallized ultra-fine (similar to 5 nm) to relatively larger (similar to 150 nm) barium titanate BTO nanoparticles in lithium fluoride (LiF) and poly(methylmethacrylate) (PMMA) dielectric matrices. No high temperature sintering was performed. The fabricated nanodielectric composites showed unique nanometric interfacial polarization properties that resulted in very promising high-frequency (>100 MHz) capacitor functions. The challenges of ferroelectric losses in the high-frequency were overcome and attributed to the possible interplay of polarization mechanisms contributed by the dielectric elements of nanostructured composites that allowed a frequency-independent capacitor performance. The best capacitor performance was achieved from as-deposited BTO-LiF nanodielectric systems that exhibited a flat capacitance density of about 10 nF/cm(2) with the self resonance frequency occurring at around 150 MHz along with a low loss tangent of about 0.1 at 100 MHz, thus verifying the high-quality of the device structures. The fabricated nanodielectric composites may be suitable for a variety of high-frequency applications in miniaturized electronic systems.