Aging and rejuvenation effects in bismuth ferrite micro-cubes

The slow dynamics of magnetization manifesting in the effects of ageing and rejuvenation was studied in bismuth ferrite BiFeO₃ multiferroic micro-cubes obtained by means of microwave assisted Pechini process. It was found that in the low temperature range, the samples exhibited irreversible magnetization vs. temperature or magnetic field and the aging and rejuvenation effects. The power-law dependence of magnetic moment decay indicated that the reconformations and/or pinning of walls of weak ferromagnetic domains make a more plausible explanation of magnetic properties of BiFeO₃ multiferroic than the canonical spin-glass mechanism.