Tunnel magnetoresistance effect and interface study in magnetic tunnel junctions using epitaxial Fe2CrSi Heusler alloy electrode
Wang, Y.-P. Han, G.-C. Lu, H. Qiu, J. Yap, Q.-J. Ji, R. Teo, K.-L.
Wang, Y.-P.
Han, G.-C.
Lu, H.
Qiu, J.
Yap, Q.-J.
Ji, R.
Citations
Altmetric:
Alternative Title
Abstract
We report the studies of magnetic tunnel junctions (MTJs) using epitaxially grown Fe2CrSi (FCS) as a bottom electrode. A tunnel magnetoresistance (TMR) ratio of 2.5% was obtained for MTJ at room temperature. The low TMR ratio is attributed to the oxidation of FCS at the interface with MgO barrier. With the insertion of 0.3 nm Mg layer between the FCS and MgO barrier layers, the TMR ratio increases to 8.1%. X-ray Photoelectron Spectroscopy results show that the FCS film is most likely terminated at Fe and Si atomic layers, which is found to be bonded to oxygen at the interface, while Cr remains at metallic state. Post-annealing effect shows that TMR first increases with annealing temperature (Ta) due to improvement in crystalline structure of MgO and top electrode and then decreases due to oxidation of the bottom electrode. The TMR finally disappears due to the depinning of top electrode induced by Mn diffusion at high Ta. © 2013 AIP Publishing LLC.
Keywords
Source Title
Journal of Applied Physics
Publisher
Series/Report No.
Collections
Rights
Date
2013-07-07
DOI
10.1063/1.4812725
Type
Article