열 화학적 환원 처리를 이용한 절연체 12CaO · 7Al2O3의 전도체로의 전환
Transition of 12CaO · 7Al2O3 electrical insulator to the permanent semiconductor using via thermo-chemical reduction treatment
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초록
마이크로 웨이브 연소합성법(microwave-assistant combustion method)를 이용하여 12CaO·7Al2O3(C12A7) 분말을성공적으로 제작하였고, H2 가스 분위기에서의 후열처리를 통하여 C12A7:H 제작에 성공하였다. 분말의 합성 여부 와 결정성 확인 및 분말 하소 시 온도에 따른 반응 분석을 위하여 X-ray diffraction(XRD) 및 TG-DSC 분석을 시행하였다. 또한, 후열처리 후 C12A7 cage 내부의 자유산소 이온이 수소 이온으로 치환되었는지 확인하기 위하여 TG-MS 분석을 시행하였고,289.5oC에서 H와 H2 가스가 방출되는 것이 확인되었으므로, H 이온이 cage 내부로 치환된 것을 확인시켜준다. 성공적으로치환된 C12A7:H 를 홀 측정기(Hall measurement)를 이용하여 전도성을 측정하여 본 결과 1000oC, Ar/H = 8 : 2의 분위기에서 8 h 이상 처리된 C12A7:H의 경우 상온(300 K)에서 102Ω·cm의 비저항 값을 나타내었다.
Abstract
The 12CaO · 7Al2O3(C12A7) powders were successfully synthesized using combustion method with microwaveassistant and C12A7:H were fabricated by post-annealed process in Ar/H atmosphere. X-ray diffraction patterns and TGDSC were used for investigating to the precursors of crystalline and reaction depending on temperature. C12A7:H that was treated post-annealed process were investigated TG-MS and Hall-measurement for confirming H ions doping and checking electrical resistivity of C12A7:H. H ion substituted to O 2− ions in the C12A7 cages were confirmed at 289.5oC by TG-MS and C12A7:H calcined at 1000oC in Ar/H = 8 : 2 atmosphere for 8~10 h has low electrical resistivity about 102Ω · cm at room temperature.
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