Self-assembled monolayers based spintronics: from ferromagnetic surface functionalization to spin-dependent transport

Abstract

Chemically functionalized surfaces are studied for a wide range of applications going from medicine to electronics. Whereas non-magnetic surfaces have been widely studied, functionalization of magnetic surfaces is much less common and has almost never been used for spintronics applications. In this article we present the functionalization of La2/3Sr1/3MnO3, a ferromagnetic oxide, with self-assembled monolayers for spintronics. La2/3Sr1/3MnO3 is the prototypical half-metallic manganite used in spintronics studies. First, we show that La2/3Sr1/3MnO3 can be functionalized by alkylphosphonic acid molecules. We then emphasize the use of these functionalized surfaces in spintronics devices such as magnetic tunnel junctions fabricated using a nano-indentation based lithography technique. The observed exponential increase of tunnel resistance as a function of alkyl chain length is a direct proof of the successful connection of molecules to ferromagnetic electrodes. For all alkyl chains studied we obtain stable and robust tunnel magnetoresistance, with effects ranging from a few tens to 10 000%. These results show that functionalized electrodes can be integrated in spintronics devices and open the door to a molecular engineering of spintronics.

Surfactant-assisted synthesis of titanium nanoMOFs for thin film fabrication

“…Considering the size determined with HR-TEM, this value suggests the deposition of roughly one NP layer. 30 Furthermore, XRD shows the characteristic Bragg peaks of the MIL-125 structure with no significant change in their relative intensities (Figure 3c), thus confirming the crystallinity of the films and ruling out any preferential orientation of the NPs on the substrate. Finally, we measured the porosity of the film by means of Kr physisorption (Figure 3c, Figure S15), a very sensitive method to assess the porosity of thin films with small absolute surface areas.…”

Combined spin filtering actions in hybrid magnetic junctions based on organic chains covalently attached to graphene

“…Indeed, oxidation occurs at the surface and it is widely known to quench the emerging spin polarization. 51 Few technological solutions were investigated such as the use of oxide materials as electrodes, 52,53 surface pre-cleaning with an appropriate acid 23 or a parallel growth/surface reduction by electrochemistry. 22,54 Graphene protection was also shown to allow preserving a metallic interface in ambient conditions as demonstrated earlier.…”

Innovation of Materials, Devices, and Functionalized Interfaces in Organic Spintronics

“…As spin‐related devices develop rapidly, the interfaces associated with them are becoming a topic of great interest in organic spintronics. Regarding the significance of spinterfaces, studies on interfacial modification by self‐assembled monolayers (SAMs) and the interfacial properties of organic–inorganic hybrid magnetic electrodes [ 14,15,28,60–62 ] are important for interpreting the effects of different spinterfaces and adjusting device performances accordingly.…”

“…These studies mainly focused on the different molecular structures of the barriers, including alkanethiolate, alkyl phosphoric acid, and other analogous molecules with different functional groups. [ 60,62,178,179 ] Galbiati et al. utilized an LSMO electrode to fabricate LSMO/C 12 H 25 PO 3 H 2 /Co‐based nanometer‐scale devices (Figure 13b).…”