Title :
Large Exchange Coupling in Synthetic Antiferromagnet With Ultrathin Seed Layer
Author :
Fukumoto, Yoshiyuki ; Honjo, Hiroaki ; Igarashi, Chuji ; Nagase, Toshihiko ; Ishiwata, Nobuyuki ; Ikegawa, Sumio ; Yoda, Hiroaki ; Tahara, Shuichi
Author_Institution :
Syst. Devices Res. Labs., NEC Corp., Kanagawa
Abstract :
Insertion of an ultrathin (les6 Aring) Ta-seed layer into the bottom NiFe layer of a synthetic antiferromagnet (SAF) grown on the AlO and MgO barriers of magnetic tunnel junctions (MTJs) significantly increased the crystal orientation of the SAF. This led to improvements of the strength and thermal robustness of the antiferromagnetic coupling (AFC) in the SAF. The magnetic properties of the films and MTJs using the SAFs were investigated. A low anisotropy field with a large AFC of the Ta-seed SAF reduced the writing field of toggle MRAMs
Keywords :
aluminium compounds; antiferromagnetic materials; iron alloys; magnesium compounds; magnetic anisotropy; magnetic storage; magnetic tunnelling; nickel alloys; random-access storage; tantalum; AlO; MgO; NiFe-Ta; antiferromagnetic coupling; crystal orientation; large exchange coupling; magnetic random access memory; magnetic tunnel junctions; synthetic antiferromagnet; ultrathin seed layer; Amorphous magnetic materials; Antiferromagnetic materials; Automatic frequency control; Couplings; Magnetic anisotropy; Magnetic properties; Magnetic tunneling; Perpendicular magnetic anisotropy; Saturation magnetization; Writing; Crystal orientation; exchange coupling; magnetic tunnel junction (MTJ); synthetic antiferromagnet (SAF); toggle MRAM;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.878864
