The influence of particle interactions on the superparamagnetic relaxation time has been studied by Mossbauer spectroscopy in samples of maghemite (gamma-Fe2O3) particles with different particle sizes and particle separations. It is found that the relaxation time decreases with decreasing particle interactions. A new model for the influence of interactions on the superparamagnetic relaxation has been derived and it is shown that this model can explain the observations.
Physical Review Letters, 1994, Vol 72, Issue 20, p. 3278-3281
PEAK; SUSCEPTIBILITY PHENOMENA; SYSTEM; MOSSBAUER-SPECTRA; GLASS; DEPENDENCE; TEMPERATURE