Magnetization Process and Interlayer Coupling in MnNi/Co/Ag(Cu)/Py High-Temperature Annealed Spin Valves
Main Article Content
Abstract
MnNi/Co/Ag/Py and MnNi/Co/Cu/Py spin valves, where Py is the symbol for permalloy Ni81Fe19, were prepared using magnetron sputtering followed by a high temperature annealing at Ta=300°C and 400°C for 30 minutes in high vacuum (~10-5 torr). The magnetization process and the magnetic coupling between ferromagnetic layers of these spin valves were investigated. The results show a weak magnetic coupling behavior, moreover, a weak positive exchange bias coupling between Co and Py layers, and a trend of an out-of-plane magnetic anisotropy in these spin valves. The origin of these features or behaviors are discussed in detailed. These results will be useful information for technological adjustments to achieve the expected properties for magnetic coupling and magnetic anisotropy of the spin valve devices.
Keywords
Spin valve, magnetization process, magnetic coupling, out-of-plane anisotropy, positive exchange biased coupling
Article Details
References
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[5] L. Jogschies, et al., Recent Developments of Magnetoresistive Sensors for Industrial Applications, Sensors 15 (2015) 28665-28689.
[6] T. Shinjo, Ch.1- Experiments of Giant Magneto-resistance, in Spin Dependent Transport in Magnetic Nanostructures, Eds. by S. Maekawa and T. Shinjo, CRC Press (LLC), Boca Raton-London-New York Washington, D.C., 2002.
[7] S.S.P. Parkin, R. Bhadra, K.P. Roche, Oscillatory Magnetic Exchange Coupling through Thin Copper Layers, Phys. Rev. Lett. 66 (1991) 2152-2155.
[8] C.-H. Chang, et al., Engineering the interlayer exchange coupling in magnetic trilayers; Sci. Rep. 5 (2015) 16844.
[9] A. Gayen, et al., Interlayer coupling in symmetric and asymmetric CoFeB based trilayer films with different domain structures: Role of spacer layer and tempe- rature, J. Magn. Magn. Mater. 462 (2018) 29-40.
[10] C.-G Lee, et al., Effects of annealing on the GMR and domain structure stabilization in a Py/Cu/Py/MnIr spin valve, J. Magn. Magn. Mater. 272-276 (2004) 1887- 1888.
[11] C. Chappert, P. Bruno; Magnetic anisotropy in metallic ultrathin films and related experiments on cobalt films, J. Appl. Phys. 64 (1988) 5736-5741.
[12] P. Bruno, J.-P. Renard; Magnetic Surface Anisotropy of Transition Metal Ultrathin Films, Appl. Phys. A 49 (1989) 499-506.
[13] P. Bruno, et al.; Magnetic hysteresis of cobalt ultrathin films with perpendicular anisotropy, J. Magn. Magn. Mater. 93 (1991) 605-608.
[14] Nguyen Anh Tuan, et al., Inverse MR and Dual-AMR Phenomena in Co/CoO/Ag/Co Sandwiches, J. Kore. Phys. Soc. 72 (2018) 786-794.
[15] F.J. Rachford, et al.; Magnetization and FMR studies of crystal-ion-sliced narrow linewidth gallium-doped yttrium iron garnet, J. Appl. Phys. 87 (2000) 6253- 6255.
[16] P. Miltenyi et al., Tuning exchange bias, Appl. Phys. Lett. 75 (1999) 2304-2306.
[17] J. Sort, et al., Exchange bias effects in Fe nanoparticles embedded in an antiferromagnetic Cr2O3 matrix, Nanotechnology 15 (2004) S211-S214.
[18] H.W. Chang, et al., Exchange bias in Co/MnPt polycrystalline films on Si(100)/SiO2 substrates with Ta underlayer, Thin Solid Films 660 (2018) 834-839.
[19] L. Sun, P. C. Searson, C. L. Chien, Asymmetrical hysteresis in exchange-biased multilayers with out-of- plane applied fields, Phys. Rev. B 71 (2005) 012417.
[20] D.E. Burgler, S.O. Demokkritov, P. Grunberg, M.T. Johnson, Ch.1: Interlayer exchange coupling in layered magnetic structures in Handbook of Magnetic Materials, Volume 13, 1st Edition, Ed. by K.H.J. Buschow, North Holland, Elsevier, 2001, 1-85.
[21] S. Brück, et al., Exploiting Length Scales of Exchange- Bias Systems to Fully Tailor Double-Shifted Hysteresis Loops, Adv. Mater. 17 (2005) 2978-2983.
[22] J.-V. Kim, et al., Angular dependence and interfacial roughness in exchange-biased ferromagnetic/anti- ferromagnetic bilayers, Phys. Rev. B 61 (2000) 8888- 8894.
[23] A.E. Berkowitz, K. Takano, Exchange anisotropy - A review, J. Magn. Magn. Mater. 200 (1999) 552-570.
[24] N.N. Phuoc, T. Suzuki; Perpendicular exchange bias mechanism in FePt/FeMn multilayers, J. Appl. Phys. 101 (2007) 09E501.