Sharp Angular Dependence of Free Layer Coercivity in Spin Valves with Ferromagnetic Interlayer Coupling

Abstract:

The dependence of free layer coercivity on the angle between easy axis and applied magnetic field was studied on [Ta, (Ni₈₀Fe₂₀)₆₀Cr₄₀]/ Ni₈₀Fe₂₀/Co₉₀Fe₁₀/Cu/Co₉₀Fe₁₀/Mn₇₅Ir₂₅/Ta spin valves with various interlayer coupling. Sharp decrease on the angle was observed for ferromagnetically coupled spin valves. The coercivity was reduced down to tenth of Oersted without any decrease of GMR-effect by forming nearly parallel anisotropy configuration. The angles at which the transition from hysteretic to anhysteretic magnetic reversal takes place are detected by analyses of the angle dependence of coercivity. Interpretation of experimental data is based on Stoner-Wohlfarth coherent rotation approach.

• Periodical: Solid State Phenomena (Volume 215)
• Pages: 474-479
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.215.474
• Online since: April 2014
• Authors: Larisa I. Naumova*, M.A. Milyaev, N.G. Bebenin, Tatyana A. Chernyshova, Vyacheslav V. Proglyado, Tatiana P. Krinitsina, Nataly S. Bannikova, Ivan Yu. Kamensky, V.V. Ustinov
• Keywords: Coercivity, Free Layer Anisotropy, Interlayer Coupling, MnIr, Spin Valve

References

[1] J. C. S. Kools, Exchange-Biased Spin-Valves for Magnetic Storage, IEEE Trans. on Magn. 32 (1996) 3165-3184.

DOI: 10.1109/20.508381

[2] C.H. Marrows, F.E. Stanley, B.J. Hickey, Angular dependence of characteristic fields in spin valves, Sensors and Actuators 81 (2000) 49 – 52.

DOI: 10.1016/s0924-4247(99)00114-4

[3] M. Labrune, J.C.S. Kools, A. Thiaville, Magnetization rotation in spin-valve multilayers, J. Magn. Magn. Mater. 171 (1997) 1-15.

DOI: 10.1016/s0304-8853(97)00085-1

[4] J.P. King, J.N. Chapman, J.C.S. Kools and M.F. Gillies, On the free layer reversal mechanism of FeMn-biased spin-valves with parallel anisotropy, J. Phys. D: Appl. Phys. 32 (1999) 1087–1096.

DOI: 10.1088/0022-3727/32/10/303

[5] Th.G.S.M. Rijks, W.J.M. de Jonge, W. Folkerts, J.C.S. Kools and R. Coehoorn, Magnetoresistance in Ni80Fe20/Cu/ Ni80Fe20/Fe50Mn50 spin valves with low coercivity and ultrahigh sensitivity, Appl. Phys. Lett. 65 (1994) 916 – 918.

DOI: 10.1063/1.112202

[6] A. De Morais and A.K. Petford-Long, Spin valve structures with artificial antiferromagnets, J. Appl. Phys. 87 (2000) 6977 – 6979.

DOI: 10.1063/1.372905

[7] R. Coehoorn Giant Magnetoresistance and Magnetic Interactions in Exchange-Biased Spin-Valves, in: K.H.J. Buschow (Ed. ), Handbook of magnetic materials, V. 15, Elsevier B.V., Amsterdam, 2003, p.1 – 199.

DOI: 10.1016/s1567-2719(03)15001-9

[8] V.V. Ustinov, M.A. Milyaev, L.I. Naumova, V.V. Proglyado, N.S. Bannikova, and T.P. Krinitsina, High-sensitive hysteresisless spin valve with a composite free layer, Phys. Met. Metallogr. 113 (2012) 341 - 348.

DOI: 10.1134/s0031918x12040151

[9] V.V. Ustinov, T.P. Krinitsina, M.A. Milyaev, L.I. Naumova, V.V. Proglyado, Low hysteresis FeMn-based top spin valve, J Nanosci. Nanotechnol. 12 (2012) 7558-7561.

DOI: 10.1166/jnn.2012.6522

[10] M.A. Milyaev, L.I. Naumova, V.V. Proglyado, T.P. Krinitsina, A.M. Burkhanov, N.S. Bannikova and V.V. Ustinov, Giant changes in magnetic and magnetoresistive properties of CoFe/Cu multilayers at subnanosized variations in the thickness of the chromium buffer layer, Phys. Met. Metallogr. 112 (2011).

DOI: 10.1134/s0031918x11020232

[11] L.I. Naumova, M.A. Milyaev, N.G. Bebenin, T.A. Chernyshova, V.V. Proglyado, T.P. Krinitsina, N.S. Bannikova, V.V. Ustinov, Anhysteretic magnetic reversal in spin valves with strong and weak interlayer coupling, Phys. Met. Metallogr. 115 (2014).

DOI: 10.1134/s0031918x14040115