DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MA: Fachverband Magnetismus

MA 55: Poster II

MA 55.21: Poster

Friday, April 4, 2014, 10:30–13:30, P2

Temperature dependent sign change in tunnel magnetoresistance of magnetic tunnel junctions with one magnetite electrode — •Luca Marnitz1, Karsten Rott1, Stefan Niehörster1, Christoph Klewe1, Daniel Meier1, Matthäus Witziok2, Andreas Krampf2, Olga Schuckmann2, Tobias Schemme2, Karsten Kuepper2, Joachim Wollschläger2, Günter Reiss1, and Timo Kuschel11Bielefeld University, Germany — 2Osnabrück University, Germany

Due to its high spin polarization and Curie temperature, magnetite (Fe3O4) is a promising material for room temperature applications in spintronics. Despite these promising features, MTJs using magnetite have not yet shown a large TMR value, the largest being -27% in CoFe/Al2O3/MgO/Fe3O4/Al2O3 (001) junctions[1]. Magnetite grown on MgO shows signs of an interdiffusion of Mg from the substrate through the magnetite at temperatures between 250 and 350C[2].

We have studied this effect by annealing CoFeB/MgO/Fe3O4/MgO (001) MTJs at different temperatures and observed a sign change from a negative TMR to a positive TMR. Additionally, MTJs with magnetite thin films treated by Ar etching showed a vastly increased TMR value of up to -12% for an annealing temperature of 230C from a starting value of about -1%. A good foundation for further research is provided, including MTJs with two magnetite electrodes with an additional NiO pinning layer and different barrier materials.

[1] T. Kado, Appl. Phys. Lett. 92, 092502 (2008)

[2] Y. Gao et al., J. Mater. Res. 13, 2003 (1998)

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2014 > Dresden