Probing the morphology of epitaxial Fe/MgO discontinuous multilayers by magnetometric technique

Discontinuous metal-insulator multilayers (DMIMs) are a special type of nanostructures with a layered arrangement of metallic particles sandwiched between continuous insulating layers. DMIMs exhibit moderate tunneling magnetoresistance (TMR) ratio but enhanced low-field sensitivity, which makes them promising candidates for magnetic field sensors. Recently we have grown epitaxial Fe/MgO DMIMs on MgO (0 0 1) single crystal substrates at different deposition conditions. Here, based on the analysis of magnetic isotherms in a broad temperature range, the effect of deposition temperature (TS) on microstructure of DMIMs is being studied and compared with the results of Transmission Electron Microscopy. It is shown that metallic layers consist of flat nanoparticles whose average size decreases, and their crystallinity improves with the increase of TS.
Portuguese team acknowledges Network of Extreme Conditions Laboratories-NECL and Portuguese Foundation of Science and Technology (FCT) support through the projects NORTE-01-0145-FEDER-022096, EXPL/IF/00981/2013 (G.N.K), and grant SFRH/BPD/81710/2011 (A.G.-G.). This work was partially supported by Spanish Ministerio de Economía y Competitividad through project MAT2017-82970-C2, and from regional Gobierno de Aragón through project E26 including FEDER funding.