Superparamagnetism and relaxation effects in granular Fe-Al₂O₃ thin films

The magnetic and electric properties of Fe-Al2O3 superparamagnetic granular films studied by various techniques, (resistivity, magnetoresistance, ac susceptibility, magnetization, γ and FM resonance) are briefly summarized. The frequency dependence of the temperature of the susceptibility maximum, TB, corresponding to the blocking of superparamagnetic particles, is discussed and compared with that of spin glasses. © 1980.