Magnetic, Electronic Structure And Interface Study Of Fe/MgO/Fe Multilayer

Jitendra Pal Singh1,6*, Sanjeev Gautam2, Braj Bhusan Singh3, Sujeet Chaudhary3, D. Kabiraj1, D. Kanjilal1,  K. H. Chae2, R. Kotnala4, Jenn-Min Lee5, Jin-Ming Chen5,  K. Asokan1*

1Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India

2Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 136-791, S. Korea

3Department of Physics, Indian Institute of Technology, New Delhi 110 016, India

4National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India

5National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan

6Department of Applied Physics, Krishna Engineering College, Ghaziabad, Uttar Pradesh 201007, India

Adv. Mater. Lett., 2014, 5 (7), pp 372-377

DOI: 10.5185/amlett.2013.105560

Publication Date (Web): Apr 27, 2014

E-mail: jitendra_singh2029@rediffmail.com, asokaniuac@gmail.com 

Abstract


MgO based magnetic tunnel junctions (MTJs) exhibit high tunneling magnetoresistance (TMR) and have potential applications in magnetic random access memories. This study addresses the role of interface in the Fe/MgO/Fe based MTJs. For present investigation, Fe/MgO/Fe multilayer stack on Si substrates is grown by electron beam evaporation method and has been investigated for structural, magnetic and electronic properties. All the layers in the stack were of polycrystalline in nature as evidenced from X-ray diffraction studies, and the magnetic measurements show the attributes perpendicular magnetic anisotropy. Results from near edge X-ray absorption spectra at Fe L-edges measured by total electron yield mode and X-ray reflectometry indicate the formation of FeOx at the Fe/MgO interface. These are associated with hybridization of Fe (3d)-O(2p) levels at Fe/MgO interface in the stack and thickness of layers in the stacks. Absence of magnetic de-coupling between top and bottom ferromagnetic layers has been attributed to interface roughness and oxidation at Fe/MgO interface. This study highlights the role of interface and oxidation that need to be considered for improving the TMR for devices.

Keywords

Magnetic multilayers, e-beam evaporation, X-ray absorption spectroscopy, X-ray reflectometry

Upcoming Congress

Knowledge Experience at Sea TM