Alternating current (ac) magnetic susceptibility was measured as a function of frequencies (1 Hz–1 kHz) and temperatures (5–300 K) in nominal Ni‐SiO2 granular films for zero field cooled samples. When temperature is well below and well above the blocking temperature Tb, the real part of the susceptibility, χ′, remains independent of frequency, while the imaginary part of the susceptibility, χ″, is essentially zero within the experimental error. Near Tb, however, both χ′ and χ″ were found to be greatly enhanced, and χ′ decreases with increasing frequency following log(f ) dependence. A scaling method was applied for χ′(f,T) to determine the distribution of energy barriers and that of particle size. © 1996 American Institute of Physics.