Anti-ferromagnetic coupling effects on energy barrier and reversal properties of recording media

Analytical solutions for coercivity H/sub CM1/, H/sub CM2/, effective (Mrt)/sub eff/, energy-barrier and effective thermal stability factor as a function of coupling constant J and other film parameters have been derived for two coupled ferromagnetic layers (FM-FM layer) with different magnetic properties for the first time. The condition for reduced effective (Mrt)/sub eff/ is analyzed. These results are valuable for laminated antiferromagnetically coupled media design. This may open up a channel to raise thermal stability significantly while maintaining lower noise for longitudinal recording media.