Papers by Author: Tian Wang

Abstract: (1-X)BaTiO3-XCaCu2.94Mn0.06Ti4O12 (BTO-CCMTO) composite ceramics with X =0.1 and 0.2 were prepared through solid state reaction route. X-ray diffraction (XRD) analyses showed that a co-existence structure of BTO and CCMTO phase can be realized when the sample was sintered at 950°C. Furthermore, influences of CCMTO on the dielectric behaviors of the BTO-CCMTO composite ceramics were investigated. The results showed that the dielectric permittivity of the BTO-CCMTO composite ceramics increases with increasing amounts of CCMTO and the Curie peak of the pure BTO ceramics is greatly suppressed due to the addition of CCMTO. The dielectric loss of the BTO-CCMTO composite ceramics can be kept in the same magnitude order as that of the BTO ceramics.

Abstract: Ultrafine-grained ceramics based on nano-scale barium titanate for BME-MLCC applications have been prepared. Relationships of milling time, microstructures and dielectric properties have been investigated. With processing selected carefully, the present ceramics show ultrafine grain size (180nm) and homogeneous microstructures, well with high dielectric constant (ε25=2550), low dielectric loss (<0.02), high resistivity, high breakdown field and X7R temperature specifications, which would be promising materials for the next generation BME-MLCC applications.

Abstract: Dielectric characteristics of strontium titanate based ceramics doped with samarium were investigated within temperature range from –60oC to 150oC. XRD was used to identify the phase compositions of the ceramics and the microstructures were characterized by SEM. Good temperature coefficient of capacitance (TCC) was observed: TCC = +18% ~ −11% with high dielectric constant of 18000 and relative low dielectric loss. After further modification, the present ceramics might be promising candidates for the multilayer ceramic capacitors applications at high temperature.