| CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY |
|
|
|
|
Effects of Fe-Oxide and Mg Layer Insertion on Tunneling Magnetoresistance Properties of CoFeB/MgO/CoFeB Magnetic Tunnel Junctions |
| Yong-Le Lou1, Yu-Ming Zhang1, Hui Guo1**, Da-Qing Xu2, Yi-Men Zhang1 |
1School of Microelectronics, Xidian University, Xi'an 710071
2School of Electrical and Control Engineering, Xi'an University of Science and Technology, Xi'an 710054
|
|
| Cite this article: |
|
Yong-Le Lou, Yu-Ming Zhang, Hui Guo et al 2016 Chin. Phys. Lett. 33 118501 |
|
|
|
|
Abstract To study the influence of CoFeB/MgO interface on tunneling magnetoresistance (TMR), different structures of magnetic tunnel junctions (MTJs) are successfully prepared by the magnetron sputtering technique and characterized by atomic force microscopy, a physical property measurement system, x-ray photoelectron spectroscopy, and transmission electron microscopy. The experimental results show that TMR of the CoFeB/Mg/MgO/CoFeB structure is evidently improved in comparison with the CoFeB/MgO/CoFeB structure because the inserted Mg layer prevents Fe-oxide formation at the CoFeB/MgO interface, which occurs in CoFeB/MgO/CoFeB MTJs. The inherent properties of the CoFeB/MgO/CoFeB, CoFeB/Fe-oxide/MgO/CoFeB and CoFeB/Mg/MgO/CoFeB MTJs are simulated by using the theories of density functions and non-equilibrium Green functions. The simulated results demonstrate that TMR of CoFeB/Fe-oxide/MgO/CoFeB MTJs is severely decreased and is only half the value of the CoFeB/Mg/MgO/CoFeB MTJs. Based on the experimental results and theoretical analysis, it is believed that in CoFeB/MgO/CoFeB MTJs, the interface oxidation of the CoFeB layer is the main reason to cause a remarkable reduction of TMR, and the inserted Mg layer may play an important role in protecting Fe atoms from oxidation, and then increasing TMR.
|
|
|
Received: 20 May 2016
Published: 28 November 2016
|
|
| PACS: |
85.70.Ay
|
(Magnetic device characterization, design, and modeling)
|
| |
85.75.Dd
|
(Magnetic memory using magnetic tunnel junctions)
|
| |
75.70.Ak
|
(Magnetic properties of monolayers and thin films)
|
| |
68.55.-a
|
(Thin film structure and morphology)
|
|
|
| Fund: Supported by the National Defense Advance Research Foundation under Grant No 9140A08XXXXXX0DZ106, the Basic Research Program of Ministry of Education of China under Grant No JY10000925005, the Scientific Research Program Funded by Shaanxi Provincial Education Department under Grant No 11JK0912, the Scientific Research Foundation of Xi'an University of Science and Technology under Grant No 2010011, and the Doctoral Research Startup Fund of Xi'an University of Science and Technology under Grant No 2010QDJ029. |
|
|
|
| [1] | Vlaic P 2010 J. Magn. Magn. Mater. 322 1438 | | [2] | Miyazaki T and Tezuka N 1995 J. Magn. Magn. Mater. 139 L231 | | [3] | Moodera J S, Kinder L R and Wong T M 1995 Phys. Rev. Lett. 74 3273 | | [4] | Wei H X, Qin Q H and Ma M 2007 J. Appl. Phys. 101 09B501 | | [5] | Zhang Z Z and Zhao H 2006 Chin. Phys. Lett. 23 932 | | [6] | Han X F, Ali S S and Liang S H 2013 Sci. Chin.: Phys. Mech. Astron. 56 29 | | [7] | Djayaprawira D D, Tsunekawa K and Nagai M 2005 Appl. Phys. Lett. 86 092502 | | [8] | Tang J, Ma B and Zhang Z Z 2010 Chin. Phys. Lett. 27 077502 | | [9] | Marnitz L, Rott K and Nieh?rster S 2015 AIP Adv. 5 047103 | | [10] | Rumaiz A K, Jaye C and Woicik J C 2011 Appl. Phys. Lett. 99 222502 | | [11] | Vincent S, David M B and Matthew T M 2013 IEEE Trans. Magn. 49 4383 | | [12] | Li X J, Jiang S L and Zhang J Y 2016 Appl. Surf. Sci. 365 275 | | [13] | Stokbro K 2008 J. Phys.: Condens. Matter 20 064216 | | [14] | Stilling M and Stokbro K 2007 J. Comput.–Aided Mater. 14 141 | | [15] | Paulsson M, Frederisksen T and Brandbyge M 2005 Phys. Rev. B 72 201101 | | [16] | Chen G, Song C and Chen C 2012 Adv. Mater. 24 3515 | | [17] | Jeong J, Aetukuri N and Graf G 2013 Science 339 1402 | | [18] | Stilling M, Stokbro K and Flensberg K 2007 Mol. Simul. 33 557 | | [19] | Butler W H, Zhang X G and Schulthess T C 2001 Phys. Rev. B 63 054416 | | [20] | Marek F, Witold S and Maciej C 2015 J. Magn. Magn. Mater. 374 451 | | [21] | Tsunekawa K, Djayaprawira D D and Nagai M 2005 Appl. Phys. Lett. 87 072503 |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
