Particle size distribution in FeAg granular alloy

A combination of Langevin and hyperbolic tangent functions weighted by a log-normal particle size distributions were used to fit the magnetization curves of Fe10Ag90 granular alloys, produced by a sol–gel process under different chemical conditions. The fitting technique allows one to get both the superparamagnetic and the blocked particle size distributions. The average size of the Fe particles obtained from the fit were in good agreement with those obtained by X-ray diffraction. The correlation between the coercive field and the particle distribution was also investigated. Zero-field cooling dc magnetic susceptibility measurements were fitted using a similar technique to that used for fitting the magnetization curves. The saturation magnetization and mean Fe particle size values obtained from the two fittings were in good agreement.