Speaker
Description
The discovery of graphene has opened novel exciting opportunities in terms of functionalities and performances for spintronics devices. It was recently shown that graphene could have a strong potential for Magnetic Tunnel Junctions (MTJs) with perspective of band filtering similar to MgO.[1][2][3][4] We present new venues where the spin filtering properties of graphene are greatly enhanced through proximity effects (a.k.a spinterface) and its integration in perp MTJs is tackled.[4][5][6]
We will show that a graphene passivation layer, integrated by low temperature catalyzed chemical vapor deposition (CVD), allows to preserve a highly sensitive surface spin current polarizer/analyzer behavior while adding enhanced spin filtering property. Indeed, the graphene layer prevents the oxidation of the ferromagnet. It thus enables the use of novel processes for spintronics devices.[4] We will illustrate this property by demonstrating efficient growth on perpendicular FM electrodes supporting potential for perpendicular anisotropy enhancement [5]. We will also demonstrate the use of ozone based ALD processes to fabricate efficient spin valves protected with graphene. Characterizations of complete spin valves making use of monolayer graphene grown by CVD will be presented. We will discuss the measured experimental spin signals in light of bulk band structure spin filtering effect,[2][3][4] but also highlight the role of interfacial hybridization for spin selection with ab-initio calculations in support.[6] The different presented experiments unveil promising uses of graphene for spintronics.
[1] Karpan et al. PRL 99, 176602 (2007)
[2] Dlubak et al. ACS Nano, 6, 10930 (2012)
[3] Martin et al. Appl. Phys. Lett. 107, 012408 (2015)
[4] Review: Piquemal-Banci et al. J. Phys. D : Appl. Phys. 50, 203002 (2017)
[5] Naganuma, VZ et al. APL, 116, 173101 (2020)
[6] Piquemal-Banci, VZ et al. Nature Comm. 11, 5670 (2020)
| Speaker Country | France |
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