Title :
Transport Properties of Magnetic Tunnel Junctions Comprising NiFeSiB/CoFeB Hybrid Free Layers
Author :
Cho, Ji Ung ; Kim, Do Kyun ; Tan, Reasmey P. ; Isogami, Shinji ; Tsunoda, Masakiyo ; Takahashi, Migaku ; Kim, Young Keun
Author_Institution :
Dept. of Mater. Sci. & Eng., Korea Univ., Seoul
fDate :
6/1/2009 12:00:00 AM
Abstract :
We report on the magneto-transport measurements of MgO magnetic tunnel junctions (MTJs) composed of NiFeSiB/CoFeB as the free layer for two different structures (top-type and bottom-type pinning). The magneto-transport properties of these MTJs were investigated by varying the thickness of the amorphous NiFeSiB layer for a fixed CoFeB thickness. The tunnel magnetoresistance (TMR), measured in both type of structures, exhibit the same or a higher amplitude (up to 230% measured at room temperature in the case of top-type device), comparing to the case of a single CoFeB free layer. These results suggest that hybrids free layers can be used as good candidates for MTJs with reduced saturation magnetization while keeping a high TMR ratio.
Keywords :
amorphous magnetic materials; boron alloys; cobalt alloys; iron alloys; magnetic multilayers; magnetisation; nickel alloys; silicon alloys; tunnelling magnetoresistance; MgO-NiFeSiB-CoFeB; TMR; amorphous layer; hybrid free layers; magnetic tunnel junctions; magnetotransport properties; room temperature; saturation magnetization; temperature 293 K to 298 K; tunnel magnetoresistance; Amorphous; NiFeSiB; hybrid free layer; magnetic tunnel junction;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2009.2018574
