암모늄 알루미늄 탄산염(hhCH)의 열분해에 의한 α-알루미나 나노분말 제조 |
오용택, 신동찬, 김상우1 |
조선대학교 신소재공학과 1KIST 재료연구부 나노재료연구센터 |
Fabrication of α-Alumina Nanopowders by Thermal Decomposition of Ammonium Aluminum Carbonate Hydroxide (AACH) |
Yong-Taeg O, Dong-Chan Shin, Sang-Woo Kim1 |
Department of Advanced Materials Engineering, Chosun University 1Nano-Materials Research Center, Korea Institute of Science and Technology |
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ABSTRACT |
[ ${alpha}-Al_2O_3$ ] nanopowders were fabricated by the thermal decomposition and synthetic of Ammonium Aluminum Carbonate Hydroxide (AACH). Crystallite size of 5 to 8 nm were fabricated when reaction temperature of AACH was low, $8^{circ}C$, and the highest $[NH_4{^+}][AlO(OH)_n{(SO_4){^-}}_{3-n/2}][HCO_3]$ ionic concentration to pH of the Ammonium Hydrogen Carbonate (AHC) aqueous solution was 10. The phase transformation fem $NH_4Al(SO_4)_2$, rhombohedral $(Al_2(SO_4)_3)$, amorphous-, ${theta}-,;{alpha}-Al_2O_3$ was examined at each temperature according to the AACH. A Time-Temperature-Transformation (TTT) diagram for thermal decomposition in air was determined. Homogeneous, spherical nanopowders with a particle size of 70 nm were obtained by firing the 5 to 8 m crystallites, which had been synthesized from AACH at pH 10 and $8^{circ}C,;at;1150^{circ}C$ for 3 h in air.Ԁ䭃䑎䷗ᜓ੯5㐰㬅K䍄乍 |
Key words:
Ammonium Aluminum Carbonate Hydroxide (AACH), PH, {\alpha}-Al_2O_3$, Nanopowders, TTT diagram |
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