Do Youp Kim

Morphology Control of Gd2O3:Eu Phosphor Particles with Cubic and Monoclinic Phases Prepared by High-Temperature Spray Pyrolysis

Gd2O3:Eu phosphor particles with cubic and monoclinic phases were directly prepared by high-temperature spray pyrolysis from aqueous, polymeric precursor and colloidal solutions. The colloidal solution with nanosized silica was effective for the preparation of Gd2O3:Eu phosphor particles with a cubic phase, a high photoluminescence intensity and a good morphology. The phosphor particles prepared from colloidal solutions with nanosized silica obtained by hydrolysis had a small size, a narrow size distribution, a spherical shape and a filled morphology. The optimum doping concentration of nanosized silica particles was 0.5 wt % of the product particles. The phosphor particles prepared by spray pyrolysis from colloidal solutions at temperatures below 1580 °C had the photoluminescence spectrra of the cubic phase and a maximum photoluminescence intensity at a temperature of 1560 °C.

The Characteristics of Fine-Sized LiMn(12-X)/6Alx/6O4(0.05≤x≤2) Powders Prepared by Spray Pyrolysis

The series of partially Al-substituted lithium manganese oxides were prepared by spray pyrolysis process from spray solutions with citric acid and ethylene glycol. The as-prepared particles obtained from spray solution with citric acid and ethylene glycol turned to fine-sized LiMn(12- x)/6Alx/6O4(0.05≤x≤2) particles with regular morphology after post-annealing. The discharge capacities of the particles post-annealed at temperature of 800oC changed from 128 to 84 mAh/g when the x of the LiMn(12-x)/6Alx/6O4 particles was changed from 0 to 2. The Al-doped LiMn2O4 fine particles prepared by spray pyrolysis from spray solution with citric acid and ethylene glycol had good cycle properties.