Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 33: Poster II

MA 33.95: Poster

Freitag, 26. März 2010, 11:00–14:00, Poster B1

Influence of roughness at interfaces on tunneling magnetoresistance in Fe/MgO/Fe — •Saeideh Edalati Boostan^1,2, Hosein Moradi², and Christian Heiliger¹ — ¹I. Physikalisches Institut, Justus Liebig University Giessen, D-35392, Germany — ²Department of Physics, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

We propose a theoretical model for magnetic tunnel junction devices with rough interfaces based on a single-band tight-binding approximation. The high tunneling magnetoresistance (TMR) for crystalline MgO barrier was observed at room temperature which is desirable for magnetic random access memory (MRAM) applications. In real junctions the Fe and MgO atoms are interdiffussed at interfaces and the numbers of diffused Fe and MgO atoms are not the same. The interface disorder is modeled by considering replacement of MgO sites by Fe atoms with a probability of n>0.5. The non-equilibrium Green's function formalism is used to calculate transport in Fe/MgO/Fe junctions. We investigate the voltage dependencies of TMR and current densities for parallel and anti-parallel configurations for majority and minority spins. The results show that the roughness decreases the TMR. The current density for the parallel (antiparallel) orientations of magnetizations decreases (increases) by including roughness at the interface.