Lithium (Li) is a key resource driving the rapid growth of the electric vehicle industry globally, with demand and prices continually on the rise. To address the limited reserves of major lithium sources such as rock and brine, research is underway on seawater Li extraction using electrodialysis and Li-ion selective membranes. Lithium lanthanum titanate (LLTO), an oxide solid electrolyte for all-solid-state batteries, is a promising Li-ion selective membrane. An important factor in enhancing its performance is employing the powder synthesis process. In this study, the LLTO powder is prepared using two synthesis methods: sol-gel reaction (SGR) and solid-state reaction (SSR). Additionally, the powder size and uniformity are compared, which are indices related to membrane performance. X-ray diffraction and scanning electron microscopy are employed for determining characterization, with crystallite size analysis through the full width at half maximum parameter for the powders prepared using the two synthetic methods. The findings reveal that the powder SGR-synthesized powder exhibits smaller and more uniform characteristics (0.68 times smaller crystal size) than its SSR counterpart. This discovery lays the groundwork for optimizing the powder manufacturing process of LLTO membranes, making them more suitable for various applications, including manufacturing high-performance membranes or mass production of membranes.

Boron nitride nanotubes (BNNTs) are receiving great attention because of their unusual material properties, such as high thermal conductivity, mechanical strength, and electrical resistance. However, high-throughput and highefficiency synthesis of BNNTs has been hindered due to the high boiling point of boron (~ 4000℃) and weak interaction between boron and nitrogen. Although, hydrogen-catalyzed plasma synthesis has shown potential for scalable synthesis of BNNTs, the direct use of H2 gas as a precursor material is not strongly recommended, as it is extremely flammable. In the present study, BNNTs have been synthesized using radio-frequency inductively coupled thermal plasma (RF-ITP) catalyzed by solid-state ammonium chloride (NH4Cl), a safe catalyst materials for BNNT synthesis. Similar to BNNTs synthesized from h-BN (hexagonal boron nitride) + H2, successful fabrication of BNNTs synthesized from h-BN+NH4Cl is confirmed by their sheet-like properties, FE-SEM images, and XRD analysis. In addition, improved dispersion properties in aqueous solution are found in BNNTs synthesized from h-BN +NH4Cl.

We synthesized YOF(yttirum oxyfluoride) powders through solid state reactions using Y2O3 and YF3 as raw materials. The synthesis of crystalline YOF was started at 300 oC and completed at 500 oC. The atmosphere during synthesis had a negligible effect on the synthesis of the YOF powder under the investigated temperature range. The particle size distribution of the YOF was nearly identical to that of the mixed Y2O3 and YF3 powders. When the synthesized YOF powders were used as a raw material for the suspension plasma spray(SPS) coating, the crystalline phases of the coated layer consisted of YOF and Y2O3, indicating that oxidation or evaporation of YOF powders occurred during the coating process. Based on thermogravimetric analysis, the crystalline formation appeared to be affected by the evaporation of fluoride because of the high vapor pressure of the YOF material.

In this study, green barium strontium silicate phosphor (BaSrSiO4:Eu3+, Eu2+) was synthesized using a solid-statereaction method in air and reducing atmosphere. Investigation of the firing temperature indicates that a single phase of BaSrSiO4is formed when the firing temperature is higher than 1400oC. The effect of firing temperature and doping concentration onluminescent properties are investigated. The light-emitting property was the best when the molar content of Eu2O3 was 0.025mol. Also, the luminescent brightness of the BaSrSiO4 fluorescent substance was the best when the particle size of the bariumwas 0.5µm. BaSrSiO4 phosphors exhibit the typical green luminescent properties of Eu3+ and Eu2+. The characteristics of thesynthesized BaSrSiO4:Eu3+, Eu2+ phosphor were investigated using X-ray diffraction (XRD) and scanning electron microscopy.The maximum emission band of the BaSrSiO4:Eu3+, Eu2+ was 520nm.

Nanocrystalline powder could be synthesized by solid-state reaction using the mixture which was prepared by a high energy milling process in a bead mill for and nanocrystalline powders mixture. Effect of the milling time on the powder characteristic of the synthesized powder was investigated. Nanocrystalline with a particle size of 50 nm was obtained at . High tetragonal powder with a tetragonality(=c/a) of 1.009 and a specific surface area of was acquired after heat-treatment at for 2 h. High energy ball milling was effective in decreasing the reaction temperature and increasing the tetragonality.

The effect of BaF2 flux in Y3Al5O12:Ce3+(YAG:Ce) formation was investigated. Phase transformation ofY3Al5O12(YAG) was characterized by using XRD, SEM, and TEM-EDS, and it was revealed that the sequential formation ofthe Y4Al2O9(YAM), YAlO3(YAP) and Y3Al5O12(YAG) in the temperature range of 1000-1500oC. Single phase of YAG wasrevealed from 1300oC. In order to find out the effect of BaF2 flux, three modeling experiments between starting materials(1.5Al2O3−2.5Y2O3, Y2O3−BaF2, and Al2O3−BaF2) were done. These modeling experiments showed that the nucleationprocess occurs via the dissolution-precipitation mechanism, whereas the grain growth process is controlled via the liquid-phasediffusion route. YAG:Ce phosphor particles prepared using a proposed technique exhibit a spherical shape, high crystallinity,and an emission intensity. According to the experimental results conducted in this investigation, 5% of BaF2 was the bestconcentration for physical, chemical and optical properties of Y3Al5O12:Ce3+(YAG:Ce) that is approximately 10-15% greaterthan that of commercial phosphor powder.

Solid-state processing via the bulk mechanical alloying enables us to directly fabricate Mg2X semi-conductive material performs. Precise control of chemical composition leads to investigation on the dilution and enrichment of X in Mg2X. Two types of solid-state reactivity are introduced: e.g. synthesis of Mg2Si from elemental mixture Mg – Si is nucleation-controlled process while synthesis of Mg2Sn from Mg – Sn, diffusion-controlled process. Thermoelectricity of these Mg2X is evaluated for discussion on the validity and effectiveness of this new PM route as a reliable tool for fabrication of thermoelectric compounds.

Abstract Direct solid state synthesis by hot pressing has been applied in order to produce high efficiency bulk specimens. Single phase with 98.5% of theoretical density was successfully produced by direct hot pressing of elemental powders containing 1.2 at.% excess Zn. Thermoelectric properties as a function of temperature were investigated from room temperature to 600 K and compared with results of other studies. Transport properties at room temperature were also evaluated. Thermoelectric properties of single phase materials produced by direct synthesis were measured and are comparable to the published data. Direct solid state synthesis by hot pressing provides a promising processing route in this material