We explain the effect of inter/intra granular exchange coupling and thermal activation on the switching behavior of nano-scale granular magnetic materials. For an ideal, non-interacting granular system, the minimum switching field occurs at 45 from the easy axis of the grains. We show through simulation and measurements, using a CoCrPt oxide-segregated granular film as a model system, that there is a clear shift in the angle of applied field at which the minimum switching field occurs. This arises solely due to incoherent reversal induced by inter-granular exchange coupling or incoherency within larger grains, rather than thermal activation. © 2011 American Institute of Physics.
- chromium compounds
- cobalt compounds
- exchange interactions (electron)
- granular materials
- magnetic switching
- magnetic thin films
- perpendicular magnetic recording