حسین رعنایی

In this thesis, the effect of external field direction on the mechanism of magnetization evolution of a Permalloy triangular nanoparticle has been investigated by using OOMMF soft ware. Magnetic patterns and also hysteresis loops depend on the external field direction. The magnetic transition is usually performed throughout the C state. This transition occurs at the switching field. If the more switching field numbers appear, then the more durability of the middle states happens. However, the variation of exchange energy also reflects the durability of the middle states. The coercivity field varies with the field rotation and therefore the soft and hard magnets can be defined via this rotation