Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions

被引:2631
作者
Yuasa, S [1 ]
Nagahama, T
Fukushima, A
Suzuki, Y
Ando, K
机构
[1] Natl Inst Adv Ind Sci & Technol, Nanoelectr Res Inst, Tsukuba, Ibaraki 3058568, Japan
[2] Japan Sci & Technol Agcy, PRESTO, Kawaguchi, Saitama 3320012, Japan
关键词
D O I
10.1038/nmat1257
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The tunnel magnetoresistance (TMR) effect in magnetic tunnel junctions (MTJs)1,2 is the key to developing magnetoresistive random-access-memory (MRAM), magnetic sensors and novel programmable logic devices3-5. Conventional MTJs with an amorphous aluminium oxide tunnel barrier, which have been extensively studied for device applications, exhibit a magnetoresistance ratio up to 70% at room temperature6. This low magnetoresistance seriously limits the feasibility of spintronics devices. Here, we report a giant MR ratio up to 180% at room temperature in single-crystal Fe/MgO/Fe MTJs. The origin of this enormous TMR effect is coherent spin-polarized tunnelling, where the symmetry of electron wave functions plays an important role. Moreover, we observed that their tunnel magnetoresistance oscillates as a function of tunnel barrier thickness, indicating that coherency of wave functions is conserved across the tunnel barrier. The coherent TMR effect is a key to making spintronic devices with novel quantum-mechanical functions, and to developing gigabit-scale MRAM.
引用
收藏
页码:868 / 871
页数:4
相关论文
共 22 条
[1]   Large magnetoresistance in Fe/MgO/FeCo(001) epitaxial tunnel junctions on GaAs(001) [J].
Bowen, M ;
Cros, V ;
Petroff, F ;
Fert, A ;
Boubeta, CM ;
Costa-Krämer, JL ;
Anguita, JV ;
Cebollada, A ;
Briones, F ;
de Teresa, JM ;
Morellón, L ;
Ibarra, MR ;
Güell, F ;
Peiró, F ;
Cornet, A .
APPLIED PHYSICS LETTERS, 2001, 79 (11) :1655-1657
[2]   Spin-dependent tunneling conductance of Fe|MgO|Fe sandwiches -: art. no. 054416 [J].
Butler, WH ;
Zhang, XG ;
Schulthess, TC ;
MacLaren, JM .
PHYSICAL REVIEW B, 2001, 63 (05)
[3]   High tunnel magnetoresistance in epitaxial Fe/MgO/Fe tunnel junctions [J].
Faure-Vincent, J ;
Tiusan, C ;
Jouguelet, E ;
Canet, F ;
Sajieddine, M ;
Bellouard, C ;
Popova, E ;
Hehn, M ;
Montaigne, F ;
Schuhl, A .
APPLIED PHYSICS LETTERS, 2003, 82 (25) :4507-4509
[4]   STABILITY OF VACANCY DEFECTS IN MGO - THE ROLE OF CHARGE NEUTRALITY [J].
GIBSON, A ;
HAYDOCK, R ;
LAFEMINA, JP .
PHYSICAL REVIEW B, 1994, 50 (04) :2582-2592
[5]   Magnetic and crystallographic properties of Co-Cr-Pt longitudinal media prepared on MgO seedlayers deposited by ECR sputtering [J].
Inaba, N ;
Futamoto, M .
IEEE TRANSACTIONS ON MAGNETICS, 2000, 36 (05) :2372-2374
[6]   Theory of tunneling magnetoresistance of an epitaxial Fe/MgO/Fe(001) junction [J].
Mathon, J ;
Umerski, A .
PHYSICAL REVIEW B, 2001, 63 (22)
[7]   Fe/MgO/FeCo(100) epitaxial magnetic tunnel junctions prepared by using in situ plasma oxidation [J].
Mitani, S ;
Moriyama, T ;
Takanashi, K .
JOURNAL OF APPLIED PHYSICS, 2003, 93 (10) :8041-8043
[8]  
MIYAZAKI T, 1995, J MAGN MAGN MATER, V139, pL231, DOI 10.1016/0304-8853(94)01648-8
[9]   Spin electronics - A quantum leap [J].
Moodera, JS ;
Leclair, P .
NATURE MATERIALS, 2003, 2 (11) :707-708
[10]   LARGE MAGNETORESISTANCE AT ROOM-TEMPERATURE IN FERROMAGNETIC THIN-FILM TUNNEL-JUNCTIONS [J].
MOODERA, JS ;
KINDER, LR ;
WONG, TM ;
MESERVEY, R .
PHYSICAL REVIEW LETTERS, 1995, 74 (16) :3273-3276