Percolative BaTiO₃/Carbon-Nanotube Composite Films Employing Aerosol Deposition

Percolative BaTiO₃/multiwalled carbon nanotube (MWNT) composite thick films were developed using an aerosol deposition (AD) process at room temperature. Well-dispersed mixed powders with various volume ratios were utilized as the starting powders for AD, and dense BaTiO₃/MWNT composite thick films were successfully fabricated with the starting mixed powders with 0.01 vol % MWNTs. The existence of MWNTs in the composite films was confirmed using Raman spectroscopy. The composite films show a high relative dielectric constant (657 at 1 kHz), which is approximately 7 times larger than that (91 at 1 kHz) of the BaTiO₃ films. In addition, the strong frequency dispersion of the dielectric constant in the low-frequency range was confirmed for the composite films. The dielectric properties of the composite films were investigated using the dielectric mechanism used in percolative composites.