Masako Toda

Novel Soft Chemical Synthesis Methods of Ceramic Materials

We report novel soft chemical synthesis method, solid hydratethermal reaction (SHR) method as a new soft chemistry. This method is very simple and can synthesize the ceramic materials just by storing the mixture of raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, nanosize YVO4 (under 100 nm in diameter) was obtained using the SHR method.

Determination of the crystal structure and photoluminescence properties of NaEu1−xGdx(MoO4)2 phosphor synthesized by a water-assisted low-temperature synthesis technique

A single-phase red-emitting NaEu(MoO4)2 phosphor with nanosized particles was synthesized using a water-assisted solid state reaction (WASSR) method, a new low-temperature synthesis method developed by our group. NaEu(MoO4)2 exhibits a monoclinic structure with a space group C2/c (no. 15), which is composed of a Na/EuO8 dodecahedron with the site occupancy of Na/Eu = 1 : 1 and an MoO4 tetrahedron. To enhance the emission intensity of the NaEu(MoO4)2 phosphor, Gd3+ was doped into the Eu3+ sites and NaEu1−xGdx(MoO4)2 (0 0.30. This indicates that the optimum composition of the phosphor for achieving a high emission intensity that is ∼3.8 times higher than that of the NaEu(MoO4)2 (x = 0) phosphor is NaEu0.70Gd0.30(MoO4)2. These phosphors exhibit a granular particle morphology with the particle size of the phosphor being ∼200 nm.

Nanophosphors synthesized by the water-assisted solid-state reaction (WASSR) method: Luminescence properties and reaction mechanism of the WASSR method

ABSTRACT Ceramic materials have been widely used in various applications and are significantly important in our daily life. The various methods for synthesizing ceramics powder materials have been already reported, and the synthesis method is known to considerably affect the characteristics and particle morphology of ceramic powder materials. We have recently developed a novel soft chemical synthesis method, named water-assisted solid-state reaction (WASSR) method, which can be synthesized at low temperatures below 100°C. We further demonstrated the effect and availability of this method on the synthesis process for ceramic oxide materials. In this paper, we review some results for the nanophosphors synthesized by the WASSR method and discuss the reaction mechanism of this method.

Development of Water Assisted Solid State Reaction for the Ceramic Materials

We report a novel soft chemical synthesis method, water assisted solid state reaction (WASSR) method. This method is very simple and can synthesize many ceramic materials just by storing or mixing raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, well-crystalline SrMoO4 was obtained using the WASSR method.