Title :
Exchange anisotropy in epitaxial Mn1-xPtx-NiFe bilayers
Author :
Kume, T. ; Nagae, E. ; Sugiyama, Y. ; Kato, T. ; Iwata, S. ; Tsunashima, S.
Author_Institution :
Dept. of Electron., Nagoya Univ., Japan
fDate :
9/1/2002 12:00:00 AM
Abstract :
Exchange anisotropy was investigated for Mn1-xPtx (x=0.05-0.25)-NiFe and NiFe-Mn1-xPtx bilayers grown by the MBE method on MgO[111] substrates. The bilayer whose NiFe layer was deposited on the MnPt layer exhibits exchange anisotropy only after annealing at 200°C. The exchange coupling constant J shows a maximum value of 0.08 [erg/cm2] at x=0.16. On the other hand, the bilayer whose MnPt layer was deposited on the NiFe layer shows large J without post annealing. In both cases, diffraction peaks from ordered phase of MnPt were not observed in the reciprocal space map measured by X-ray diffraction. The origin of the exchange anisotropy is attributed to the antiferromagnetic spin arrangements of the MnPt layer with a disordered face-centered cubic structure.
Keywords :
X-ray diffraction; annealing; antiferromagnetic materials; coercive force; exchange interactions (electron); interface magnetism; iron alloys; magnetic epitaxial layers; magnetic hysteresis; manganese alloys; molecular beam epitaxial growth; nickel alloys; platinum alloys; 200 degC; MBE method; MgO; MgO[111] substrates; Mn1-xPtx-NiFe; X-ray diffraction; annealing; antiferromagnetic spin arrangements; disordered face-centered cubic structure; epitaxial Mn1-xPtx-NiFe bilayers; exchange anisotropy; exchange coupling constant; reciprocal space map; Anisotropic magnetoresistance; Annealing; Antiferromagnetic materials; Heat treatment; Iron alloys; Magnetic films; Molecular beam epitaxial growth; Spin valves; Substrates; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.803115
