Structure analysis and local magnetic parameters of magnetoresistance tunnel junctions

• Autorzy: Kim C. , Kim C. O. , Hu Y. , Kanak J. , Stobiecki T. , Ogata S. , Tsunoda M. , Takahashi M.
• Języki publikacji: EN

Abstrakty

EN

The Magnetoresistance Tunnel Junctions (MTJ) were deposited by DC magnetron sputtering method in the following layer sequence: Ta(50A)/Cu(100A)/Ta(50A)/Ni80Fe20(20A)/Cu(50A)/Mn75Ir25(100A)/Co70Fe30(25A)/Al-O/Co70Fe30(25A)/Ni80Fe20(t) /Ta(50A)/, with t = 0A, 100A and 1000A. X-ray diffraction analysis revealed that highly oriented fcc-(111) of IrMn3, Cu, Ni80Fe20 and Co70Fe30 crystal planes are stacked parallel to the substrate plane. The improvement of (111) texture and crystallinity was observed after annealing. The tunneling magnetoresistance ratio of patterned junction with electrode layer of Ni80Fe20 (t = 1000A), deposited on the free layer of Co70Fe30 (25A) exceeds 40% at room temperature after annealing at 200°C in magnetic field 1kOe. The local hysteresis loops were measured using the magneto-optical Kerr effect system. The relatively irregular variations of coercive force Hc and unidirectional anisotropy field Hua in as-deposited sample are revealed. After 200°C annealing Hc decreases but Hua increases with smooth local variations. Two-dimensional plots of Hc and Hua show the symmetric saddle shapes with their axes aligned with the pinned layer. The distribution of surface roughness is symmetric with respect to the center of MTJ. Correlation between surface roughness and the variation of Hua suggests that the Hua variation of the free layer is well described by dipole interactions in the form of socalled Néel "orange peel" coupling.

Słowa kluczowe

EN

coercive force; exchange coupling; TMR; XRD; MOKE; surface roughness

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Materials Science
• Rocznik: 2003
• Tom: Vol. 21, No. 1
• Strony: 9--23
• Opis fizyczny: Bibliogr. 25 poz.

Twórcy

autor

Kim C.

• Department of Materials Engineering, Chungnam National University, Taejon, Korea

autor

Kim C. O.

• Department of Materials Engineering, Chungnam National University, Taejon, Korea

autor

Hu Y.

• Department of Materials Engineering, Chungnam National University, Taejon, Korea

autor

Kanak J.

• Department of Electronics, University of Mining and Metallurgy, 30-059 Krakow, Poland

autor

Stobiecki T.

• Department of Electronics, University of Mining and Metallurgy, 30-059 Krakow, Poland

autor

Ogata S.

• Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan

autor

Tsunoda M.

• Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan

autor

Takahashi M.

• Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan

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