Title :
Large Exchange Bias and High Blocking Temperature of MgO-Barrier-MTJs With L12-Ordered Mn3Ir
Author :
Komagaki, Koujiro ; Yamada, Kouji ; Noma, Kenji ; Kanai, Hitoshi ; Kobayashi, Kazuo ; Uehara, Yuji ; Tsunoda, Masakiyo ; Takahashi, Migaku
Author_Institution :
Fujitsu Ltd., Nagano
Abstract :
We examined the magnetic properties of CoFeB/MgO/CoFeB based magnetic tunnel junctions (MTJs) with L12(ordered)-Mn3Ir or gamma(disordered)-Mn75Ir25 as an antiferromagnetic (AFM) layer. Both of them showed tunnel magnetoresistance (TMR) ratio of about 160% after 350degC annealing. The exchange bias field (Hex) of the MTJs with L12-Mn3 Iris significantly larger than that with gamma-MnIr. The blocking temperature (TB) of the MTJ film with L12-Mn3Ir is about 50degC higher than that with gamma-MnIr. These results prove that L12-Mn3Ir is a great candidate as AFM in MgO-barrier-MTJs and makes them improve in exchange bias properties.
Keywords :
annealing; boron alloys; cobalt alloys; exchange interactions (electron); iron alloys; magnesium compounds; magnetic tunnelling; magnetoresistance; tunnelling magnetoresistance; CoFeB-MgO - Interface; antiferromagnetic layer; blocking temperature; exchange bias; magnetic tunnel junctions; tunnel magnetoresistance ratio; Annealing; Antiferromagnetic materials; Iron; Magnetic properties; Magnetic sensors; Magnetic tunneling; Sputtering; Substrates; Temperature sensors; Tunneling magnetoresistance; Blocking temperature; L1$_{2}$(ordered)-Mn$_{3}$Ir; MgO barrier; exchange bias; tunnel junction; tunnel magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2007.893695
