Electric and thermo spin transfer torques in Fe/Vacuum/Fe tunnel junction

Abstract

We present first-principle calculations of electric and thermo spin transfer torques (STT) in Fe/Vacuum(Vac)/Fe magnetic tunnel junctions (MTJs). Our quantitative studies demonstrate rich bias dependence of STT and tunnel magneto resistance (TMR) behaviors with respect to the interface roughness. Thermoelectric effects in Fe/Vac/Fe MTJs is remarkable. We observe larger ZT of 6.2 in 8 ML clean Vacuum barrier, where the heavily restrained thermal conductance should be responsible for. Thermo-STT in Fe/Vac/Fe MTJs show same order as that in Fe/MgO/Fe MTJs with similar barrier thickness.

Graphical abstract

Keywords

spin transfer torque / Fe/Vacuum/Fe tunnel junction / thermoelectric effect

References

[1] H. Kubota, A. Fukushima, K. Yakushiji, T. Nagahama, S. Yuasa, K. Ando, H. Maehara, Y. Nagamine, K. Tsunekawa, D. D. Djayaprawira, N. Watanabe, and Y. Suzuki, Quantitative measurement of voltage dependence of spin-transfer torque in MgO-based magnetic tunnel junctions, Nat. Phys., 2008, 4(1): 37

[2] J. C. Sankey, Y. T. Cui, J. Z. Sun, J. C. Slonczewski, R. A. Buhrman, and D. C. Ralph, Measurement of the spintransfer-torque vector in magnetic tunnel junctions, Nat. Phys., 2008, 4(1): 67

[3] A. M. Deac, A. Fukushima, H. Kubota, H. Maehara, Y. Suzuki, S. Yuasa, Y. Nagamine, K. Tsunekawa, D. D. Djayaprawira, and N. Watanabe, Bias-driven high-power microwave emission from MgO-based tunnel magnetoresistance devices, Nat. Phys., 2008, 4(10): 803

[4] D. C. Ralph and M. D. Stiles, Spin transfer torques, J. Magn. Magn. Mater., 2008, 320(7): 1190

[5] X. Jia, K. Xia, Y. Ke, and H. Guo, Nonlinear bias dependence of spin-transfer torque from atomic first principles, Phys. Rev. B, 2011, 84(1): 014401

[6] X. Jia, K. Xia, and G. E. W. Bauer, Thermal spin transfer in Fe/MgO/Fe tunnel junctions, Phys. Rev. Lett., 2011, 107(17): 176603

[7] Y. Ke, K. Xia, and H. Guo, Oxygen-vacancy-induced diffusive scattering in Fe/MgO/Fe magnetic tunnel junctions, Phys. Rev. Lett., 2010, 105(23): 236801

[8] C. Wang, Y. T. Cui, J. A. Katine, R. A. Buhrman, and D. C. Ralph, Time-resolved measurement of spin-transferdriven ferromagnetic resonance and spin torque in magnetic tunnel junctions, Nat. Phys., 2011, 7(6): 496

[9] S. Yuasa, T. Nagahama, A. Fukushima, Y. Suzuki, and K. Ando, Giant room-temperature magnetoresistance in singlecrystal Fe/MgO/Fe magnetic tunnel junctions, Nat. Mater., 2004, 3(12): 868

[10] J. C. Slonczewski, Current-driven excitation of magnetic multilayers, J. Magn. Magn. Mater., 1996, 159: L1

[11] L. Berger, Emission of spin waves by a magnetic multilayer traversed by a current, Phys. Rev. B, 1996, 54: 9353

[12] I. Theodonis, N. Kioussis, A. Kalitsov, M. Chshiev, and W. H. Butler, Anomalous bias dependence of spin torque in magnetic tunnel junctions, Phys. Rev. Lett., 2006, 97(23): 237205

[13] J. C. Slonczewski, Currents, torques, and polarization factors in magnetic tunnel junctions, Phys. Rev. B, 2005, 71(2): 024411

[14] J. Xiao, G. Bauer, and A. Brataas, Spin-transfer torque in magnetic tunnel junctions: Scattering theory, Phys. Rev. B, 2008, 77(22): 224419

[15] M. Wilczyński, J. Barnaś, and R. Świrkowicz, Free-electron model of current-induced spin-transfer torque in magnetic tunnel junctions, Phys. Rev. B, 2008, 77(5): 054434

[16] A. Manchon, N. Ryzhanova, A. Vedyayev, M. Chschiev, and B. Dieny, Description of current-driven torques in magnetic tunnel junctions, J. Phys.: Condens. Matter, 2008, 20(14): 145208

[17] S. Wang, Y. Xu, and K. Xia, First-principles study of spintransfer torques in layered systems with noncollinear magnetization, Phys. Rev. B, 2008, 77(18): 184430

[18] Z. Yuan, S. Wang, and K. Xia, Thermal spin-transfer torques on magnetic domain walls, Solid State Commun., 2010, 150(11-12): 548

[19] C. Heiliger and M. D. Stiles, Ab initio studies of the spintransfer torque in magnetic tunnel junctions, Phys. Rev. Lett., 2008, 100(18): 186805

[20] G. E. W. Bauer, A. H. MacDonald, and S. Maekawa, Spin caloritronics, Solid State Commun., 2010, 150(11-12): 459

[21] G. E. W. Bauer, E. Saitoh, and B. J. van Wees, Spin caloritronics, Nat. Mater., 2012, 11(5): 391

[22] M. Hatami, G. E. W. Bauer, Q. F. Zhang, and P. J. Kelly, Thermal spin-transfer torque in magnetoelectronic devices, Phys. Rev. Lett., 2007, 99(6): 066603

[23] M. Hatami, G. E. W. Bauer, Q. Zhang, and P. J. Kelly, Thermoelectric effects in magnetic nanostructures, Phys. Rev. B, 2009, 79(17): 174426

[24] H. Yu, S. Granville, D. P. Yu, and J. Ph. Ansermet, Evidence for thermal spin-transfer torque, Phys. Rev. Lett., 2010, 104(14): 146601

[25] J. C. Slonczewski, Initiation of spin-transfer torque by thermal transport from magnons, Phys. Rev. B, 2010, 82(5): 054403

[26] G. Autés, J. Mathon, and A. Umerski, Theory of tunneling magnetoresistance of Fe/GaAs/Fe(001) junctions, Phys. Rev. B, 2010, 82: 115212

[27] X. Jia and K. Xia, Thermal electric effects in Fe-GaAs-Fe tunnel junctions, AIP Advances, 2012, 2(4): 041411

[28] P. Vlaic, N. Baadji, M. Alouani, H. Dreysse, O. Eriksson, O. Bengone, and I. Turek, Calculated electronic and transport properties of Fe/GaAs/Fe(001) tunnel junctions, Surf. Sci., 2004, 566-568: 303

[29] V. Popescu, H. Ebert, N. Papanikolaou, R. Zeller, and P. H. Dederichs, Influence of spin-orbit coupling on the transport properties of magnetic tunnel junctions, Phys. Rev. B, 2005, 72(18): 184427

[30] P. X. Xu, V. M. Karpan, K. Xia, M. Zwierzycki, I. Marushchenko, and P. J. Kelly, Influence of roughness and disorder on tunneling magnetoresistance, Phys. Rev. B, 2006, 73: 180402(R)

[31] Y. Ke, K. Xia, and H. Guo, Disorder scattering in magnetic tunnel junctions: Theory of nonequilibrium vertex correction, Phys. Rev. Lett., 2008, 100(16): 166805

[32] I. Turek, V. Drchal, J. Kudrnovský, M. Śob, and P. Weinberger, Electronic Structure of roughnessed Alloys, Surfaces and Interfaces, Boston: Kluwer, 1997

[33] S. H. Vosko, L. Wilk, and M. Nusair, Accurate spindependent electron liquid correlation energies for local spin density calculations: A critical analysis, Can. J. Phys., 1980, 58(8): 1200

[34] H. van Houten, L. W. Molenkamp, C. W. J. Beenakker, and C. T. Foxon, Thermo-electric properties of quantum point contacts, Semicond. Sci. Technol., 1992, 7(3B): B215

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