Size dependence of magnetic characteristics measured on separate nickel particles

摘要

Interference electron microscopy was applied to measure the coercive force, the magnetic saturation and the residual magnetization of separated nickel particles. Nickel particles with perfect sphericity and radius from 10 to 100 nm were produced directly in the interference electron microscope by means of wire explosion caused by the passage of an electric current pulse through it. We find a decrease of the magnetic saturation and an increase of the coercive force with decreasing size of the separate particles. If there are neighbouring particles, with decreasing the distance to them coercive force is characterized by more smooth size dependence and has less absolute value. This observation shows the contribution of the interparticle interaction.