THE HIGH-TEMPERATURE PROPERTIES OF TIN-DOPED MAGNETITE

Materials of composition Fe3-xSnxO4 (x = 0.1 and 0.2) have been prepar ed. The Sn-119 Mossbauer spectra show a magnetic hyperfine field demon strating an interaction between Fe3+ ions on the tetrahedral A sites a nd Sn4+ ions on the octahedral B sites of Fe3O4. Fe-57 Mossbauer spect roscopy shows the Curie temperatures of the materials to be lower than those of magnetite and related titanomagnetites, The Fe-57 and Sn-119 Mossbauer spectra also show the exsolution of tin from the tin-doped magnetite after prolonged treatment at elevated temperatures. (C) 1996 Academic Press, Inc.