Influence of film composition in quaternary Heusler alloy Co2(Mn,Fe)Si thin films on tunnelling magnetoresistance of Co2(Mn,Fe)Si/MgO-based magnetic tunnel junctions

被引：99

作者：

Liu, Hong-xi ^{[1
]}

Kawami, Takeshi ^{[1
]}

Moges, Kidist ^{[1
]}

Uemura, Tetsuya ^{[1
]}

Yamamoto, Masafumi ^{[1
]}

Shi, Fengyuan ^{[2
]}

Voyles, Paul M. ^{[2
]}

机构：

[1] Hokkaido Univ, Grad Sch Informat Sci & Technol, Div Elect Informat, Sapporo, Hokkaido 0600814, Japan

[2] Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA

来源：

JOURNAL OF PHYSICS D-APPLIED PHYSICS | 2015年 / 48卷 / 16期

基金：

美国能源部;

关键词：

Heusler alloy thin films; half-metallic character; magnetic tunnel junctions; tunneling magnetoresistance; Co-2(Mn; Fe)Si; Co2MnSi; PHOTOELECTRON-SPECTROSCOPY; ROOM-TEMPERATURE; SPIN INJECTION; COBALT;

D O I：

10.1088/0022-3727/48/16/164001

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The influence of off-stoichiometry on the half-metallic character of quaternary Heusler alloy thin films of Co-2(Mn,Fe)Si (CMFS) was investigated by studying the composition dependence of the tunnelling magnetoresistance (TMR) ratio of fully epitaxial CMFS/MgO/CMFS magnetic tunnel junctions (CMFS MTJs) having Co-2(Mn alpha'Fe beta')Si-0.84 electrodes with various Mn and Fe compositions. It was found that MJTs with (Mn + Fe)-rich electrodes had higher TMR ratios than ones with (Mn + Fe)-deficient electrodes at 4.2 and 290 K. These results indicate that the suppression of Co antisites at nominal Mn/Fe sites is critical to obtaining half-metallic quaternary Co-2(Mn,Fe)Si in a similar way as in ternary alloy Co2MnSi. CMFS MTJs with Mn-rich and lightly Fe-doped CMFS electrodes showed giant TMR ratios of 2610% at 4.2 K and 429% at 290 K. These results suggest that Co-based Heusler alloy thin films would be highly applicable to spintronic devices because of their half-metallicity and material diversity arising from not only ternary alloy but also quaternary alloy systems.

引用

页数：9

共 52 条

[31] Hard X-ray photoelectron spectroscopy on buried, off-stoichiometric CoxMnyGez (x:z=2:0.38) Heusler thin films [J].

Ouardi, Siham ;

Fecher, Gerhard H. ;

Chadov, Stanislav ;

Balke, Benjamin ;

Kozina, Xenia ;

Felser, Claudia ;

Taira, Tomoyuki ;

Yamamoto, Masafumi .

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 2013, 111 (02) :395-405

[32] Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers [J].

Parkin, SSP ;

Kaiser, C ;

Panchula, A ;

Rice, PM ;

Hughes, B ;

Samant, M ;

Yang, SH .

NATURE MATERIALS, 2004, 3 (12) :862-867

[33] Role of structural defects on the half-metallic character of Co2MnGe and Co2MnSi Heusler alloys -: art. no. 094423 [J].

Picozzi, S ;

Continenza, A ;

Freeman, AJ .

PHYSICAL REVIEW B, 2004, 69 (09)

[34]

Picozzi S, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.094421

[35] Co2FeSi/GaAs/(Al,Ga)As spin light-emitting diodes:: Competition between spin injection and ultrafast spin alignment [J].

Ramsteiner, M. ;

Brandt, O. ;

Flissikowski, T. ;

Grahn, H. T. ;

Hashimoto, M. ;

Herfort, J. ;

Kostial, H. .

PHYSICAL REVIEW B, 2008, 78 (12)

[36] Spin Injection, Transport, and Detection at Room Temperature in a Lateral Spin Transport Device with Co2FeAl0.5Si0.5/n-GaAs Schottky Tunnel Junctions [J].

Saito, Tatsuya ;

Tezuka, Nobuki ;

Matsuura, Masashi ;

Sugimoto, Satoshi .

APPLIED PHYSICS EXPRESS, 2013, 6 (10)

[37] Extensive study of giant magnetoresistance properties in half-metallic Co2(Fe,Mn)Si-based devices [J].

Sakuraba, Y. ;

Ueda, M. ;

Miura, Y. ;

Sato, K. ;

Bosu, S. ;

Saito, K. ;

Shirai, M. ;

Konno, T. J. ;

Takanashi, K. .

APPLIED PHYSICS LETTERS, 2012, 101 (25)

[38] Mechanism of large magnetoresistance in Co2MnSi/Ag/Co2MnSi devices with current perpendicular to the plane [J].

Sakuraba, Y. ;

Izumi, K. ;

Iwase, T. ;

Bosu, S. ;

Saito, K. ;

Takanashi, K. ;

Miura, Y. ;

Futatsukawa, K. ;

Abe, K. ;

Shirai, M. .

PHYSICAL REVIEW B, 2010, 82 (09)

[39] Large Magnetoresistance Effect in Epitaxial Co2Fe0.4Mn0.6Si/Ag/Co2Fe0.4Mn0.6Si Devices [J].

Sato, Jo ;

Oogane, Mikihiko ;

Naganuma, Hiroshi ;

Ando, Yasuo .

APPLIED PHYSICS EXPRESS, 2011, 4 (11)

[40] Effects of off-stoichiometry on the spin polarization at the Co2MnβGe0.38/MgO interfaces: X-ray magnetic circular dichroism study [J].

Singh, V. R. ;

Verma, V. K. ;

Ishigami, K. ;

Shibata, G. ;

Kadono, T. ;

Fujimori, A. ;

Asakura, D. ;

Koide, T. ;

Miura, Y. ;

Shirai, M. ;

Li, G. -F. ;

Taira, T. ;

Yamamoto, M. .

PHYSICAL REVIEW B, 2012, 86 (14)

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