Influence of long-range interactions on the switching behavior of particles in an array of ferromagnetic nanostructures

Abstract

The interaction of Co/Pt nanodots is studied by means of the anomalous Hall-effect. On purpose the system of four dots is driven into a state of instability by applying a magnetic field perpendicular to the easy axis of magnetization. The dots become susceptible to thermal excitation and correlated switching is observed over large distances. The experimental finding is supported by theoretical simulations that reveal the importance of correlations and their influence at large length scales. This unexpected result sheds light on the general behavior of ensembles of systems with small energy barriers like superparamagnetic ensembles or switching of high density bit pattern media around the switching field.

Keywords

• magnetism
• interaction
• patterned media
• magnetization dynamics
• nanoparticle
• nanodot