Title :
Recording potential of anti-ferromagnetically coupled longitudinal media
Author :
Richter, H.J. ; Girt, Er.
Author_Institution :
Seagate Recording Media, Fremont, CA, USA
fDate :
7/1/2001 12:00:00 AM
Abstract :
A rigorous calculation of the switching fields and the energy barriers of anti-ferromagnetically coupled (AFC) grains is reported. It is found that the field dependence of the energy barrier for an AFC grain differs slightly from that of a grain reversing by coherent rotation, which implies that the dynamic coercivity curves also differ slightly. It is estimated that AFC media can gain 0.5 to 1 dB SNR by virtue of the flattening of the dynamic coercivity curve, and an additional 0.5 dB due to reduced demagnetizing fields. It is also found that dynamic effects can facilitate switching of AFC media at high speeds
Keywords :
RKKY interaction; antiferromagnetic materials; coercive force; demagnetisation; free energy; magnetic hysteresis; magnetic multilayers; magnetic recording; magnetic switching; superparamagnetism; thermal stability; Gibbs free energy; RKKY-like interaction; antiferromagnetically coupled grains; antiferromagnetically coupled longitudinal media; curve flattening; dynamic coercivity curves; energy barriers; field dependence; hysteresis loops; recording potential; reduced demagnetizing fields; superparamagnetic effect; switching fields; synthetic antiferromagnet; thermal decay; thermal stability; Anisotropic magnetoresistance; Antiferromagnetic materials; Automatic frequency control; Coercive force; Energy barrier; Magnetic anisotropy; Magnetic recording; Magnetic switching; Perpendicular magnetic anisotropy; Saturation magnetization;
Journal_Title :
Magnetics, IEEE Transactions on
