The magnetic disaccommodation in aluminium ferrites

The domain wall stabilization processes in aluminium substituted magnetite is investigated by means of disaccommodation techniques. The time evolution of the initial magnetic susceptibility after sample demagnetization is measured for polycrystalline specimens with nominal composition AlxFe3-xO4, 0 less than or equal to x less than or equal to 1, around room temperature. We show that the presence of Al3+ ions in this structure involves the splitting of the original process III found in vacancy-doped magnetite in many similar processes, according to the different arrangements for the Al3+ ions inside the spinel structure. (C) 1999 Elsevier Science B.V. All rights reserved.