Inscription and stabilization of ferromagnetic patterns on arrays of magnetic nanocylinders

Magnetic Nanocylinders (MNs) result axially parallel and forming triangular arrays immersed in the membrane used to produce them. As the individual magnetization points along each cylinder axis either inward or outward of the membrane plane, the net magnetization of the set is nil. However, a localized and strong enough magnetic field applied over such MNs array can revert the magnetization of individual MNs. This fact opens the possibility to inscribe ferromagnetic patterns (FPs) over the membrane surface as an alternative way to store fixed information. Patterns with different geometrical shapes and also letters under the arial font were tested. In this frame we have studied the total energy per cylinder for FPs within a circular membrane containing a huge amount of MNs. To prevent spontaneous magnetization reversion, with the consequently information lost, we propose a simple stabilization mechanism.