Magnetic properties of ferrocolloids

Abstract The influence of interparticle magneto-dipole interactions and the disperse composition of ferrocolloids upon their static and dynamic magnetic properties is investigated. It is found that both factors make commensurable contributions to the formation of static properties. Comparison of the experimental results with the predictions of various exactly soluble theoretical models accounting for interparticle interactions allows one to give preference to so-called mean-spherical model. The dynamic properties of ferrocolloids are determined mainly by the particles' dispersedness. The temperature, concentration, frequency and field dependences of the magnetization can be described quantitatively without involving any hypotheses about phase transitions of ferrocolloids into a magnetically ordered state or into a dipole glass state.