Title :
Structural and microscopic analyses of (α-Fe2O3/Co(NiFe)/Cu/Co(NiFe)) bottom GMR spin valves
Author :
Bae, Seongtae ; Egelhoff, William F. ; Chen, P.J. ; Judy, Jack H.
Author_Institution :
MINT, Minnesota Univ., Minneapolis, MN, USA
fDate :
9/1/2000 12:00:00 AM
Abstract :
The structural and microscopic analyses of Si/α-Fe2 O3/Co(NiFe)/Cu/Co(NiFe) bottom GMR spin valves with Co or NiFe free and pinned layers were performed from the point of view of material characteristics. The input sputtering power, substrate bias, and sputtering power source (RF, or DC magnetron) were used as experimental variables. It was confirmed that the crystal structure of α-Fe2O3 related to the antiferromagnetic crystalline anisotropy, the surface roughness associated with coupling field (bias field) between the free and the pinned layers through the nonmagnetic Cu layer, and the interdiffusion were crucial factors in determining the GMR performance of Si/α-Fe2O3/Co(NiFe)/Cu/Co(NiFe). The increase of Ni-Cu intermixing region due to the Cu interdiffusion was shown to be a much more dominant factor as compared to the interfacial surface roughness in reduction of GMR ratio in α-Fe2O 3 bottom spin valve
Keywords :
Auger electron spectra; X-ray diffraction; atomic force microscopy; chemical interdiffusion; cobalt; copper; crystal structure; giant magnetoresistance; interface roughness; iron alloys; iron compounds; magnetic multilayers; nickel alloys; spin valves; sputter deposition; sputtered coatings; surface topography; α-Fe2O3/Co(NiFe)/Cu/Co(NiFe) bottom; AES; AFM; Fe2O3-Co-Cu-Co; Fe2O3-NiFe-Cu-NiFe; GMR performance; GMR spin valves; XRD; antiferromagnetic crystalline anisotropy; bias field; coupling field; crystal structure; free layers; input sputtering power; interdiffusion; interfacial roughness; intermixing region; material characteristics; microscopic analysis; pinned layers; sputtering power source; structural analysis; substrate bias; surface roughness; Antiferromagnetic materials; Crystalline materials; Crystallization; Magnetic materials; Microscopy; Performance analysis; Rough surfaces; Spin valves; Sputtering; Surface roughness;
Journal_Title :
Magnetics, IEEE Transactions on
