Article ID Journal Published Year Pages File Type
1666400 Thin Solid Films 2013 5 Pages PDF
Abstract
Here we present a scanning tunneling microscopy study of electrical conductivity of (110)-oriented MgO ultrathin films grown on hexagonal close-packed Co(0001) surface by molecular beam epitaxy, being a good candidate for tunneling barrier for future-generation spintronic devices. Three-dimensional growth of the tunneling barrier, expected for compressive strains emerging at the Co/MgO interface, is demonstrated by reflection high-energy electron diffraction and atomic force microscopy. The 5 eV height of the full barrier of MgO is reached at a layer thickness of 4 nm. Thinner MgO layers exhibit randomly distributed spots of the high conductance on the tunneling current map. The current-voltage curves indicate the existence of vacancies in MgO crystal lattice, lowering the resistivity of the tunneling barrier.
Related Topics
Physical Sciences and Engineering Materials Science Nanotechnology
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