In this study, a spray dryer is used to make granules of Y2O3 and YF3, and then Y5O4F7 is synthesized following heat treatment of them under Ar gas atmosphere at 600 oC. Single and binary monomer mixtures are compared and analyzed to optimize photocurable monomer system for DLP 3D printing. The mixture of HEA and TMPTA at 8:2 ratio exhibits the highest photocuring properties and low viscosity with shear thinning behavior. The optimized photocurable monomer and synthesized Y5O4F7 are therefore mixed and applied to printing process at variable solid contents (60, 70, 80, & 85 wt.%) and light exposure times. Under optimal light exposure conditions (initial exposure time: 1.2 s, basic exposure time: 5 s), YOF composites at 60, 70 & 80 wt.% solid contents are successfully printed. As a result of measuring the size of the printed samples compared to the dimensions of the designed bar type specimen, the deviation is found to increase as the YOF solid content increases. This shows that it is necessary to maximize the photocuring activity of the monomer system and to optimize the exposure time when printing using a high-solids ceramic slurry.

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.

A3-2x/3Al1-zInzO4F: Eux3+ (A=Ca, Sr, Ba, x=-0.15, z=0, 0.1) oxyfluoride phosphors were simply prepared by thesolid-state method at 1050oC in air. The phosphors had the bright red photoluminescence (PL) spectra of an A3-2x/3Al1-zInzO4Ffor Eu3+ activator. X-ray diffraction (XRD) patterns of the obtained red phosphors were exhibited for indexing peak positionsand calculating unit-cell parameters. Dynamic excitation and emission spectra of Eu3+ activated red oxyfluoride phosphors wereclearly monitored. Red and blue shifts gradually occurred in the emission spectra of Eu3+ activated A3AlO4F oxyfluoridephosphors when Sr2+ by Ca2+ and Ba2+ ions were substituted, respectively. The concentration quenching as a function of Eu3+contents in A3-2x/3AlO4F:Eu3+ (A=Ca, Sr, Ba) was measured. The interesting behaviors of defect-induced A3-2x/3Al1-zInzO4-αF1-δphosphors with Eu3+ activator are discussed based on PL spectra and CIE coordinates. Substituting In3+ into the Al3+ positionin the A3-2x/3AlO4F:Eu3+ oxyfluorides resulted in the relative intensity of the red emitted phosphors noticeably increasing byseven times.