Preparation and Dielectric Properties of 3D Barium Titanate Colloidal Sphere Array
Barium titanate (BaTiO3) colloidal sphere array was prepared by meniscus method using capillary force between particles from slurry. To pack particles closely, well-dispersed slurry was obtained using electric double layer. From SEM observation, it was confirmed that the colloidal sphere array had point contact or plane contact. Dielectric permittivity of prepared colloidal sphere array was measured at 1 MHz by impedance analyzer. An obtained sample with point contact showed about the same dielectric permittivity as that of simulation by finite element method (FEM) using closed packed model. However, colloidal sphere arrays with plane contact showed lower permittivity than a sample with point contact. From XRD measurement of these samples, it was suggested that the low permittivity was originated from lattice strain or smallness of particle size.
Keiichi Katayama, Kazumi Kato, Tadashi Takenaka, Masasuke Takata and Kazuo Shinozaki
A. Yazawa et al., "Preparation and Dielectric Properties of 3D Barium Titanate Colloidal Sphere Array", Key Engineering Materials, Vol. 320, pp. 127-130, 2006