2023, Vol.33, No.1

Journal of the Korean Crystal Growth and Crystal Technology 2023 KCI Impact Factor : 0.19

pISSN : 1225-1429 / eISSN : 2234-5078
https://journal.kci.go.kr/jkcgct

A non-rare earth-based strontium-aluminate red light emitting phosphor was synthesized by a solid-state reaction method and the effect of synthesis temperature and Mn4+ activator concentration on the photoluminescence characteristics of the phosphor was studied. The synthesized SrAl2O4:Mn4+ phosphor showed broad band absorption characteristics in the near-ultraviolet and blue regions with peaks at wavelengths of near 330 and 460 nm, and a triple band deep red emission consisted of three peaks at near 644, 658, and 673 nm. The SrAl2O4:Mn4+ phosphor synthesized at a temperature 1600°C and a Mn4+ activator concentration of 0.5 mol% showed the strongest PL emission intensity, and concentration quenching was observed at concentrations higher than 0.7 mol%. FE-SEM and DLS particle size distribution analysis showed that the synthesized SrAl2O4:Mn4+ phosphor had a particle size distribution of 2~6.4 µm and an irregular spherical shape with an average particle size of ~4 µm.

Forty Viscosity data of glass bottles fabricated in a glass bottle manufacturing plant for 4 years were calculated using Lakatos model. The relationship between the glass bottle compositions and viscosities at log η of 3, 6.6, 10 and 12.3 Pa·s was analyzed. MgO that was a component of the glass bottle showed the maximum coefficient of variation of 0.89, but it gave a very small change in the viscosity. CaO that was another component of the glass bottle lowered theisokom temperature because it tended to reduce the number of non-bridging oxygen at temperature below a softening point.

To prepare zinc oxide powder, three types of sodium-based alkali precipitants such as NaOH, Na₂CO₃, NaOH/NaHCO₃ were compared to the differences in the manufacturing process of zinc oxide powder from zinc precipitate products like intermediates with the consideration of thermodynamic reaction. The prepared zinc precipitate products by the reaction with the sodium-based alkali precipitant were confirmed to respectively hydroxy zinc chloride (Zn5(OH)8Cl₂·H₂O) and zinc carbonate hydroxide (Zn5(OH)6(CO₃)₂·H₂O) from XRD analysis. Zinc oxide particles were compared in heat treatment at 800°C according to sodium-based alkali precipitants. The mixed NaOH and NaHCO₃ of alkali precipitant reaction was contributed to synthesize the more uniform zinc oxide particles.