International Journal of Advanced Materials Research
Articles Information
International Journal of Advanced Materials Research, Vol.1, No.2, May 2015, Pub. Date: May 28, 2015
Magnetoresistance in Ferromagnet/Wide Band Gap Polymer Structures
Pages: 64-72 Views: 1327 Downloads: 401
Authors
[01] A. N. Lachinov, Bashkir State Pedagogical University, Department of Applied Physics and Nanotechnologies, Ufa, Russia; Ufa Research Centre of Russian Academy of Sciences, Ufa, Russia.
[02] N. V. Vorob’eva, Bashkir State Pedagogical University, Department of Applied Physics and Nanotechnologies, Ufa, Russia.
[03] A. A. Lachinov, Bashkir State Pedagogical University, Department of Applied Physics and Nanotechnologies, Ufa, Russia; Institute of Molecule and Crystal Physics URC RAS, Ufa, Russia.
Abstract
The appearance of spintronics of polymeric materials is an important step in the development of spintronics. In the scope of this trend, it seems important to consider the possibilities of the non-traditional polymer functional materials – the polymers with a wide band gap. The results of study of the conductivity change in magnetic field for CPP (current perpendicular to the plane) geometry are presented in the current work with respect to the heterostructures containing a layer of such polymer material. Reversible electronic conductivity switching, driven by an external magnetic field, exists in the asymmetric system of Ni/polydiphenylenephthalide (film)/non-ferromagnetic metal. It is possible to change the sign of magnetoresistive phenomena by changing the magnitude of the external influence and (or) the initial electronic state of the polymeric material. The value of the threshold magnetic field for the switching of conductivity depends on the initial magnetic state of the charge-injecting ferromagnetic electrode. The phenomenon of the electronic conductivity switching of wide band gap polymer film, driven by an external magnetic field, has the character of resonance tunnelling and takes place providing that there is coincidence of the energy level of permitted states in the charge-injecting electrode and the thin energy band of coherent charge transfer in the middle of the band gap of the polymer film. The electronic conductivity switching is closely connected with partial spin polarization of current that is injected from the ferromagnet to the polymer. Evidence of spin transport is obtained in the symmetric structure of the CPP type of spin valve with polymeric spin-transport layer thickness no less than 800 nm. Theoretical models of these phenomena are discussed and the conclusion is drawn that the use of polymers with a wide band gap is certainly promising as the functional materials of spintronics.
Keywords
Polymer Electronics, Spintronics, Magnetism, Magnetic Materials, Conductivity Switching
References
[01] P.N. Hai, S. Ohya, M. Tanaka, S.E. Barnes and S. Maekawa, Electromotive force and huge magnetoresistance in magnetic tunnel junctions, Nature 458, 2009, 489-492.
[02] S.E. Barnes and S. Maekawa, Generalization of Faraday’s Law to include nonconservative spin forces, Phys. Rev. Lett. 98, 2007, 246601.
[03] J.-W. Yoo, H.W. Jang, V.N. Prigodin, C. Kao, C.B. Eom, A.J. Epstein, Tunneling vs. giant magnetoresistance in organic spin valve, Synth. Met. V 160, 2010, 216-222.
[04] P. Janssen, M. Cox, S.H.W. Wouters, M. Kemerink, M.M. Wienk and B. Koopmans, Tuning organic magnetoresistance in polymer-fullerene blends by controlling spin reaction pathways, Nature Communications 4, 2013, 2286, DOI: 10.1038/ncomms3286
[05] P. Janssen, Spins in organic semiconductors, Technische Universiteit Eindhoven, 2013.
[06] Y. Wu, Z.-Ha Xu, B. Hu and J. Howe, Tuning magnetoresistance and magnetic-field-dependent electroluminescence through mixing a strong-spin-orbital-coupling molecule and a weak-spin-orbital-coupling polymer, Phys. Rev. B 75, 2007, 035214.
[07] A.N. Lachinov, V.M. Kornilov, T.G. Zagurenko and A.Yu. Zherebov, On the high conductivity of nonconjugated polymers, JETP 102, 2006, 640-645.
[08] A.N. Lachinov and N.V. Vorob’eva, Electronics of thin wideband polymer layers, Physics-Uspekhi 49(12), 2006, 1223-1238.
[09] K. Gatner, A.N. Lachinov, M. Matlak, A. Slebarski, T.G. Zagurenko, arXiv:cond-mat/0503432v1 [cond-mat.str-el]
[10] V.O. Vas’kovskii, P.A. Savin, V.N. Lepalovskii, A.A. Ryazantsev, Multilevel interaction between layers in layered film structures, Physics of the Solid State 39 (12), 1997, 1958-1960.
[11] A.N. Lachinov, J. Genoe, N.V. Vorob’eva, A.A. Lachinov, F.F. Garifullina, V.M. Kornilov, Magnetoresistance phenomena in ferromagnetic/wide band gap polymer system, Synthetic Metals V 161, 2011, 642–645.
[12] А.N. Lachinov, N.V. Vorob’eva, A.А. Lachinov, Giant magnetoresistance in the polymer-ferromagnetic system, Mol. Cryst. Liq. Cryst. 467, 2007, 135-142.
[13] A.N. Lachinov, N.V. Vorob’eva, A.A. Lachinov, On the nature of giant magnetoresistance in a ferromagnet-polymer-nonmagnetic metal system, Tech. Phys. Letters 35, 2009, 349-351.
[14] Vonsovskii, S.V., Magnetism, Nauka, Moscow, 1971.
[15] P.C van Son, H. van Kempen, P. Wyder, Boundary resistance of the ferromagnetic-nonferromagnetic metal interface, Phys. Rev. Lett. 58 (21), 1987, 2271-2273.
[16] A.N. Lachinov, N.V. Vorob’eva, V.M. Kornilov, B.A. Loginov, V.A. Bespalov, On the role of spin polarization of electrons of giant injection magnetoresistance in the Ni-polymer-Cu system, Physics of the Solid State 50, 2008, 1502-1505.
[17] N.V. Vorob’eva, A.N. Lachinov, F.F. Garifullina, Influence of a metallic substrate’s magnetic state on the giant magnetoresistance of a ferromagnet–polymer structure, Bulletin of the Russian Academy of Sciences: Physics 74 (10), 2010, 1357–1359.
[18] Sze, S.M., Physics of Semiconductor Devices, Wiley-Interscience, 1981.
[19] A.N. Lachinov, N.V. Vorob’eva, and A.A. Lachinov, The role of the wide-band-gap polymer layer for the existence of conductivity switching in the valve structure, Physics of the Solid State 54 (2), 2012, 428–432.
[20] N.V. Vorob’eva, A.N. Lachinov, Huge magnetoresistance of structures based on nonferromagnetic wideband polymers, Bulletin of the Russian Academy of Sciences. Physics 77(10), 2013, 1238-1240.
[21] N. Kh. Useinov, Tunneling characteristics of a double-barrier magnetic junction, Physics of the Solid State 55 (3), 2013, 659-667.
[22] S.T. Carr, B.N. Narozhny, A.A. Neresyan, Effect of a Local Perturbation in a Fermionic Ladder, Phys. Rev. Lett. 106, 126805.
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