出版日期：2002-01-01 00:00:00

著者：Yu, Hsuan-fu; Huang, Kao-chao

單位：淡江大學化學工程與材料工程學系

出版者：New York: Cambridge University Press

著錄名稱、卷期、頁數：Journal of materials research 17(1), pp.199-203

摘要：Ultrafine BaFe12O19 powder with crystallite sizes less than 200 nm was prepared via a citric acid precursor method. Citric acid was added into an aqueous solution, containing nitrates of Ba2+ and Fe3+ in a stoichiometric ratio to form barium ferrite, to chelate metallic ions in the solution. The pH of aqueous solutions was adjusted with NH4OH. After ethylene glycol was added into the solution and the system temperature was raised, esterification and dehydratation led to the formation of solid ester precursor. The distribution and contents of metallic ions in the ester are affected by the [citric acid]/[metallic ions] molar ratio used and the pH of starting solutions. When the ester-precursor obtained at pH = 9 with [citric acid]/[metallic ions] = 1.5 was used, crystalline BaFe12O19 appeared at temperatures as low as 923 K, and pure barium ferrite was obtained at 1073 K. According to the experimental results obtained, the reaction mechanism involved in the pyrolysis of esters is proposed and discussed.

語言：en

ISSN：2044-5326 0884-2914

期刊性質：國外

收錄於：SCI EI

通訊作者：Yu, Hsuan-fu

國別：USA

出版型式：紙本 電子版