The gamma-irradiation-induced chemical change from beta-FeOOH to Fe3O4

The reactions of gamma-irradiation on 5 mm beta-FeOOH in the presence of is opropanol and water have been investigated. In the initial stage of the gam ma-irradiation, beta-FeOOH turned into alpha-FeOOH. With the gamma-irradiat ion continued, alpha-FeOOH was slowly reduced to Fe3O4. After the gamma-irr adiation with a dose of 64.3 kGy, all the beta-FeOOH and alpha-FeOOH disapp eared and the product was a single phase of Fe3O4, which had an average par ticle size of 54 nm. The process of this reaction is discussed. The gamma-i rradiation of beta-FeOOH should be a new method of preparing magnetite. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.