In this research, a precipitation method was used to synthesize β-Ga2O3 powders with various particle morphologies and sizes under varying precipitation conditions, such as gallium nitrate concentration, pH, and aging temperature, using ammonium hydroxide and ammonium carbonate as precipitants. The obtained powders were characterized in detail by XRD, SEM, FT-IR, and TG-DSC. From the TG-DSC result, GaOOH phase was transformed to β-Ga2O3 at around 742˚C, and weight loss percent was about 14 % when NH4OH was used as a precipitant. Also, β-Ga2O3 formed at 749˚C and weight loss percent was about 15 % when (NH)2CO3 was used as a precipitant. XRD results showed that the obtained Ga2O3 had pure monoclinic phase in both cases. When (NH)2CO3 was used as a precipitant, the particle shape changed and became irregular. The range of particle size was about 500nm-4μm based on various concentrations of gallium nitrate solution with NH4OH. The particle size was increased from 1-2μm to 3-4μm and particle shape was changed from spherical to bar type by increasing aging temperature over 80˚C.

Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) 조성을 갖는 치밀한 관형 분리막은 압출 성형 방법으로 제조하였다. Ba0.5Sr0.5Co0.8Fe0.2O3-δ 관형 분리막의 구조적 특성은 x-선 회절분석기 (XRD)와 전자 주사 현미경 (SEM)을 이용하여 분석하였으며, 상대밀도는 94.10%를 보였다. 산소투과량 분석은 700~950℃ 범위에서 공급 측과 투과 측의 운전조건에 따라 측정되었다. 공급 측과 투과 측에서 대기 중 공기와 진공펌프를 사용할 경우, Ba0.5Sr0.5Co0.8Fe0.2O3-δ 관형 분리막의 산소투과량은 900℃에서 1.37 mL/min·㎠로 높게 나타났다.