NiFe/Pt双层薄膜中的自旋霍尔磁阻
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摘要
【目的】研究NiFe/Pt双层薄膜中的自旋霍尔磁阻(SMR),其中NiFe是铁磁金属导体。【方法】用标准四探针法测量不同Pt层厚度的NiFe/Pt电阻,通过拟合得到Pt层和NiFe层的电阻率;测量NiFe/Pt薄膜纵向磁电阻的磁场依赖特性。【结果】Pt层电阻率远小于NiFe层电阻率,表明电流几乎仅在Pt层流通。此外,界面处的自旋混合电导及纵向电阻Rxx的磁场角度依赖特性进一步表明Rxx由SMR主导,没有各向异磁阻(AMR)的贡献。分别在x,y和z轴施加磁场均观测到SMR,但是SMR的磁阻率不同,最大约为0.1%。不同磁场下SMR的角度依赖特性表明SMR可由小磁场控制。【结论】基于SMR的新型磁阻传感器可用于海洋科学技术中磁场信息探测。
【Objective】The spin Hall magentoresistance(SMR) was studied in NiFe/Pt bilayers, where NiFe is a ferromagnetic metal.【Methods】The Pt thickness dependence of resistance of Ni Fe/Pt was measured by the standard four-point Hall probing system, and the resistivity of Pt and NiFe layers was obtained with the fitting. Subsequently, the magnetic field dependent longitudinal magentoresistance of NiFe/Pt bilayer was measured. 【Results】The resistivity of Pt layer was much smaller than that of the NiFe layer, which indicates that all the current only follows in Pt layer. In addition, both the spin-mixing conductance at the interface and angular dependence of the longitudinal resistance Rxx further indicate that Rxx is dominated by SMR without the contribution of anisotropic magnetoresistance. SMR can be observed under the external field applied in x, y and z axes, respectively. However, the magnetoresistance ratio is different among them, and the maximum difference is about 0.1%. The angular dependent SMR in the NiFe/Pt bilayer under various magnetic fields indicates that SMR can be controlled by a small magnetic field. 【Conclusion】The results of this study indicates that the SMR-based magentoresistive sensor could be used for the detection of magnetic fields in marine science and technology.
【Objective】The spin Hall magentoresistance(SMR) was studied in NiFe/Pt bilayers, where NiFe is a ferromagnetic metal.【Methods】The Pt thickness dependence of resistance of Ni Fe/Pt was measured by the standard four-point Hall probing system, and the resistivity of Pt and NiFe layers was obtained with the fitting. Subsequently, the magnetic field dependent longitudinal magentoresistance of NiFe/Pt bilayer was measured. 【Results】The resistivity of Pt layer was much smaller than that of the NiFe layer, which indicates that all the current only follows in Pt layer. In addition, both the spin-mixing conductance at the interface and angular dependence of the longitudinal resistance Rxx further indicate that Rxx is dominated by SMR without the contribution of anisotropic magnetoresistance. SMR can be observed under the external field applied in x, y and z axes, respectively. However, the magnetoresistance ratio is different among them, and the maximum difference is about 0.1%. The angular dependent SMR in the NiFe/Pt bilayer under various magnetic fields indicates that SMR can be controlled by a small magnetic field. 【Conclusion】The results of this study indicates that the SMR-based magentoresistive sensor could be used for the detection of magnetic fields in marine science and technology.
引文
[1]MCGUIRE T R,POTTER R I.Anisotropic magnetoresistance in ferromagnetic 3d alloys[J].IEEETrans Magn,1975,11(4):1018-1038.
[2]BAIBICH M N,BROTO J M,FERT A,et al.Giant magnetoresistance of(001)Fe/(001)Cr magnetic superlattices[J].Phys Rev Lett,1988,61(21):2472.
[3]FERT A.Nobel lecture:origin,development,and future of spintronics[J].Rev Mod Phys,2008,80:1517.
[4]PARKIN S S P,KAISER C,PANCHULE A,et al.Giant tunnelling magnetoresistance at room temperature with Mg O(100)tunnel barriers[J].Nature Materials,2004,3:862-867.
[5]MIYAZAKI and TEZUKA N.Giant magnetic tunneling effect in Fe/Al2O3/Fe junction[J].Journal of Magnetism and Magnetic Materials,1995,139(3):231-234.
[6]关政军,陈小凤.磁传感器在航海上的应用[J].大连海事大学学报,2006,32(2):45-48.
[7]熊方.MEMS航姿测量系统在航海领域的设计研究[J].船舶科学技术,2017,39(5A):37-39.
[8]吴招才,高多耀,罗孝文,等.海洋地磁三分量测量技术[J].地球物理学进展,2011,26(3):902-907.
[9]邱兵.基于入侵的海洋浮标传感器应用分析[J].电子元器件与信息技术,2018,8(14):51-53.
[10]赵铁虎,齐君,阮大双,等.基于地磁与红外双模探测的海洋浮标预警系统设计[J].海洋技术学报,2017,36(5):15-21.
[11]NAKAYAMA H,ALTHAMMER M,CHEN Y T,et al.Spin Hall magentoresistance induced by a nonequilibrium proximity effect[J].Phys Rev Lett,2013,110(20):206601.
[12]ISASA M,BEDOYA-PINTO A,VELEZ S,et al.Spin Hall magnetoresistance at Pt/CoFe2O4 interfaces and texture effects[J].Appl Phys Lett,2014,105(14):142402.
[13]VLIETSTRA N,SHAN J,CASTEL V,et al.Exchange magnetic field torques in YIG/Pt bilayers observed by the spin-Hall magnetoresistance[J].Appl Phys Lett,2013,103(3):032401.
[14]DAI Z W,HUANG X F,YANG D C,et al.Influence of the two boundaries of the Pt layer on spin current transportation by spin Hall magnetoresistance[J].Journal of Magnetism and Magnetic Materials,2018,465:585-589.
[15]GAMINO M,SILVA E F,SANTOS O A,et al.The role of metallic nanoparticles in the enhancement of the spin-Hall magnetoresistance n YIG/Pt thin films[J].Journal of Magnetism and Magnetic Materials,2018,466:267-272.
[16]KIM J,SHENG P,TAKAHASHI S,et al.Spin Hall magnetoresistance in metallic bilayers[J].Phys Rev Lett,2016,116:097201.
[17]HUANG S Y,LI H L,CHONG C W,et al.Interface-induced spin Hall magnetoresistance enhancement in Pt-based tri-layer structure[J].Scientific reports,2018,8:108.
[18]毛晶,龙丽霞,张磊,等.D8 advance X射线衍射仪测试ITO薄膜厚度[J].实验室科学,2017,20(1):29-32.
[19]HAO Q,XIAO G.Giant spin Hall effect and switching induced by spin-transfer torque in a W/Co40Fe40B/MgOstructure with perpendicular magnetic anisotropy[J].Phys Rev A,2015,3(3):034009.
[20]HAN J H,SONG C,LI F,et al.Antiferromagnet-controlled spin current transport in SrMnO3/Pt hybrids[J].Phys Rev B,2014,90:144431.
[2]BAIBICH M N,BROTO J M,FERT A,et al.Giant magnetoresistance of(001)Fe/(001)Cr magnetic superlattices[J].Phys Rev Lett,1988,61(21):2472.
[3]FERT A.Nobel lecture:origin,development,and future of spintronics[J].Rev Mod Phys,2008,80:1517.
[4]PARKIN S S P,KAISER C,PANCHULE A,et al.Giant tunnelling magnetoresistance at room temperature with Mg O(100)tunnel barriers[J].Nature Materials,2004,3:862-867.
[5]MIYAZAKI and TEZUKA N.Giant magnetic tunneling effect in Fe/Al2O3/Fe junction[J].Journal of Magnetism and Magnetic Materials,1995,139(3):231-234.
[6]关政军,陈小凤.磁传感器在航海上的应用[J].大连海事大学学报,2006,32(2):45-48.
[7]熊方.MEMS航姿测量系统在航海领域的设计研究[J].船舶科学技术,2017,39(5A):37-39.
[8]吴招才,高多耀,罗孝文,等.海洋地磁三分量测量技术[J].地球物理学进展,2011,26(3):902-907.
[9]邱兵.基于入侵的海洋浮标传感器应用分析[J].电子元器件与信息技术,2018,8(14):51-53.
[10]赵铁虎,齐君,阮大双,等.基于地磁与红外双模探测的海洋浮标预警系统设计[J].海洋技术学报,2017,36(5):15-21.
[11]NAKAYAMA H,ALTHAMMER M,CHEN Y T,et al.Spin Hall magentoresistance induced by a nonequilibrium proximity effect[J].Phys Rev Lett,2013,110(20):206601.
[12]ISASA M,BEDOYA-PINTO A,VELEZ S,et al.Spin Hall magnetoresistance at Pt/CoFe2O4 interfaces and texture effects[J].Appl Phys Lett,2014,105(14):142402.
[13]VLIETSTRA N,SHAN J,CASTEL V,et al.Exchange magnetic field torques in YIG/Pt bilayers observed by the spin-Hall magnetoresistance[J].Appl Phys Lett,2013,103(3):032401.
[14]DAI Z W,HUANG X F,YANG D C,et al.Influence of the two boundaries of the Pt layer on spin current transportation by spin Hall magnetoresistance[J].Journal of Magnetism and Magnetic Materials,2018,465:585-589.
[15]GAMINO M,SILVA E F,SANTOS O A,et al.The role of metallic nanoparticles in the enhancement of the spin-Hall magnetoresistance n YIG/Pt thin films[J].Journal of Magnetism and Magnetic Materials,2018,466:267-272.
[16]KIM J,SHENG P,TAKAHASHI S,et al.Spin Hall magnetoresistance in metallic bilayers[J].Phys Rev Lett,2016,116:097201.
[17]HUANG S Y,LI H L,CHONG C W,et al.Interface-induced spin Hall magnetoresistance enhancement in Pt-based tri-layer structure[J].Scientific reports,2018,8:108.
[18]毛晶,龙丽霞,张磊,等.D8 advance X射线衍射仪测试ITO薄膜厚度[J].实验室科学,2017,20(1):29-32.
[19]HAO Q,XIAO G.Giant spin Hall effect and switching induced by spin-transfer torque in a W/Co40Fe40B/MgOstructure with perpendicular magnetic anisotropy[J].Phys Rev A,2015,3(3):034009.
[20]HAN J H,SONG C,LI F,et al.Antiferromagnet-controlled spin current transport in SrMnO3/Pt hybrids[J].Phys Rev B,2014,90:144431.