Papers by Author: Wei Hsing Tuan

Abstract: In the present study, the BaTiO3/Ni composites were prepared by using the pressureless sintering technique. The ferroelectric and ferromagnetic properties of the composites are measured. The composites exhibit ferroelectric properties only when the Ni content is as low as 1 vol.%. Nevertheless, the saturated magnetization of the BaTiO3/Ni composites increases with the increase of Ni content. The BaTiO3/Ni composites exhibit multiferroic characteristics.

Abstract: In the present study, several principles are introduced as the guidelines to design multi- phased materials. Each phase in the multiphase material can offer one function or property to the material. The functions contributed from the phases within the multiphase material can interact with each other. Such interactions can be tailored by suitable microstructure design. The Al2O3-ZrO2-Ni multiphase material is used to demonstrate the applications of the design principles.

Abstract: Manganese oxide powders were prepared by spray pyrolysis from manganese acetate solution with various pyrolysis temperatures and directly collected via high-voltage electrostatic deposition technique (ESD). The as-prepared powders were coated onto graphite substrates by electrophoretic deposition technique (EPD). The as-prepared powders and/or coatings were examined by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and etc. XRD data determined the phase of the as-prepared powders as nanocrystalline Mn3O4 phase, manganese hydroxide and residual acetate. In addition, the electrochemical characteristics of the resulting powder mixtures were examined by cyclic voltammetry and charge/discharge cycling in electrolyte for redox supercapacitor applications.

Abstract: In the present study, the processing-properties relationships of the ZrO2/(Ni+Al2O3) composites are examined. Dense composites were prepared either by pulse electrical current sintering (PECS) at 1350C for 5 minutes or by pressureless sintering (PLS) at 1600C for 1 h. The size of Ni particles is as small as 30 nm to 50 nm. Though the size of ZrO2 grains in the matrix increases as alumina and nickel particles are added, the strength of the ZrO2/(Ni+Al2O3) composites is significantly higher than that of monolithic ZrO2.