Interacting superparamagnetic nanoparticles in the Cu–1%Co single crystal

The results of experimental and theoretical magnetic studies performed for the Cu–1%Co single crystal containing the magnetic Co nanoparticles embedded in the non-magnetic Cu matrix are presented and discussed. The shape of the hysteresis loop measured at room temperature was analysed within the frame of the interacting superparamagnetic particles formalism. The original theoretical model was improved, taking into account the response of each nanoparticle to the mean interaction field. To check the validity of the applied theory, the theoretical magnetization curve was calculated and compared with the experimental data. Additionally, the apparent size distribution of the Co nanoparticles was determined. To obtain the true size distribution of the Co nanoparticles, the scaling procedure including the relation between the interaction field and the characteristic temperature was applied. The result of the scaling was compared with the Co nanoparticles size distribution known from the previous TEM analysis leading to satisfactory agreement between both sets of data. - Highlights: ► We study the magnetic interactions between Co nanoparticles in the non-magnetic Cu matrix. ► We use the interacting superparamagnetic particles model and calculate the magnetization curve. ► The true nanoparticles size distribution is determined. ► The scaling procedure related to the interaction field is introduced. ► Good correlation between the theoretical and experimental data validates the applied model