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. 2020 Mar 31;10(22):13006-13015.
doi: 10.1039/c9ra09003g. eCollection 2020 Mar 30.

Exploring room-temperature transport of single-molecule magnet-based molecular spintronics devices using the magnetic tunnel junction as a device platform

Pawan Tyagi  1 , Christopher Riso  1 , Uzma Amir  1 , Carlos Rojas-Dotti  2 , Jose Martínez-Lillo  2
Affiliations

Exploring room-temperature transport of single-molecule magnet-based molecular spintronics devices using the magnetic tunnel junction as a device platform

Pawan Tyagi et al. RSC Adv. .

Abstract

A device architecture utilizing a single-molecule magnet (SMM) as a device element between two ferromagnetic electrodes may open vast opportunities to create novel molecular spintronics devices. Here, we report a method of connecting an SMM to the ferromagnetic electrodes. We utilized a nickel (Ni)-AlO x -Ni magnetic tunnel junction (MTJ) with the exposed side edges as a test bed. In the present work, we utilized an SMM with a hexanuclear [Mn6(μ3-O)2(H2N-sao)6(6-atha)2(EtOH)6] [H2N-saoH = salicylamidoxime, 6-atha = 6-acetylthiohexanoate] complex that is attached to alkane tethers terminated with thiols. These Mn-based molecules were electrochemically bonded between the two Ni electrodes of an exposed-edge tunnel junction, which was produced by the lift-off method. The SMM-treated MTJ exhibited current enhancement and transitory current suppression at room temperature. Monte Carlo simulation was utilized to understand the transport properties of our molecular spintronics device.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Fig. 1
Fig. 1. 3D view of MTJ with exposed side edges (a) before and (b) after the bridging of SMM channels. (c) Magnified view of one SMM covalently bonded with two Ni electrodes. (d) SEM of a complete SMM-based MTJMSD. (e) View along the crystallographic [111] direction of the molecular structure of the SMM. H atoms and ethanol molecules of crystallization have been omitted for clarity. Color code: pink, Mn; yellow, S; red, O; blue, N; black, C.
Fig. 2
Fig. 2. (a) Representative I–V of a bare MTJ after 48 hours. (b) Variation in current of six MTJs at 50 mV after 48 hours. (c) AFM image showing topography of an MTJ. (d) AFM measurements of the cross-section of the junction along the dashed line in panel (c). (e) AFM measurements of the cross-section of top Ni electrode. (f) Stability of the top Ni electrode state subjected to alternating ±0.1 V in the bare state, after immersion in ethanol, and after immersion in SMM solution in ethanol solvent.
Fig. 3
Fig. 3. (a) Representative I–V of a bare MTJ. Inset shows that MTJs were submerged under SMM solution with two electrodes to apply ±100 mV. (b) Current vs. time spectra recorded between two electrodes placed in molecular solution on an MTJ. (c) Multiple I–V showing SMM effect on bare MTJ transport. (d) Histogram of 34 MTJs before and after hosting SMM channels along the edges.
Fig. 4
Fig. 4. SMM-MTJMSD showing (a) suppressed current state and (b) nA level suppressed current state transitioning to the high μA level high current state. The suppressed current level could be quite stable (c) or in an ultra-low current state (d) where only noise could be recorded. (e) Histogram of 11 MTJs showing the suppressed current state after hosting SMM channels between Ni ferromagnetic electrodes.
Fig. 5
Fig. 5. (a) SMM-MTJMSD showing magnetization's effect. (b) MFM of bare MTJ (c) FMR of an array of MTJ pillars before and after treating them with SMM.
Fig. 6
Fig. 6. Magnetization versus thermal energy (kT) graph for the 3D Ising model of the SMM-based MTJMSD when JSMM-T and JSMM-B are of same magnitude and with (a) the same sign and (b) the opposite sign.
See this image and copyright information in PMC

References

    1. Leuenberger M. N. Mucciolo E. R. Berry-phase oscillations of the kondo effect in single-molecule magnets. Phys. Rev. Lett. 2006;97(12):126601. doi: 10.1103/PhysRevLett.97.126601. - DOI - PubMed
    2. Bogani L. Wernsdorfer W. Molecular spintronics using single-molecule magnets. Nat. Mater. 2008;7(3):179–186. doi: 10.1038/nmat2133. - DOI - PubMed
    1. Affronte M. Troiani F. Ghirri A. Candini A. Evangelisti M. Corradini V. Carretta S. Santini P. Amoretti G. Tuna F. Timco G. Winpenny R. E. P. Single molecule magnets for quantum computation. J. Phys. D: Appl. Phys. 2007;40(10):2999–3004. doi: 10.1088/0022-3727/40/10/S01. - DOI
    2. Coronado E. Epsetin A. J. Molecular spintronics and quantum computing. J. Mater. Chem. 2009;19(12):1670–1671. doi: 10.1039/B901955N. - DOI
    3. Bartolome J., Luis F. and Fernandez J. F., Molecular Magnets: Physics and Applications, Springer, 2014
    1. Heersche H. B. de Groot Z. Folk J. A. van der Zant H. S. J. Romeike C. Wegewijs M. R. Zobbi L. Barreca D. Tondello E. Cornia A. Electron transport through single Mn-12 molecular magnets. Phys. Rev. Lett. 2006;96(20):206801. doi: 10.1103/PhysRevLett.96.206801. - DOI - PubMed
    1. Cinchetti M. Dediu V. A. Hueso L. E. Activating the molecular spinterface. Nat. Mater. 2017;16(5):507–515. doi: 10.1038/nmat4902. - DOI - PubMed
    2. Sanvito S. Molecular spintronics the rise of spinterface science. Nat. Phys. 2010;6(8):562–564.
    1. Tyagi P. Baker C. D'Angelo C. Paramagnetic Molecule Induced Strong Antiferromagnetic Exchange Coupling on a Magnetic Tunnel Junction Based Molecular Spintronics Device. Nanotechnology. 2015;26:305602. doi: 10.1088/0957-4484/26/30/305602. - DOI - PubMed
    2. Tyagi P. Friebe E. Large Resistance Change on Magnetic Tunnel Junction based Molecular Spintronics Devices. J. Magn. Magn. Mater. 2018;453:186–192. doi: 10.1016/j.jmmm.2018.01.024. - DOI