自旋阀多层膜的电化学制备及其巨磁电阻效应  

Electrochemical Preparation and Giant Magnetoresistance Effect of Spin-valve Multilayers

作　　者：姚素薇[1] 姜莹[1] 张卫国[1] 

机构地区：[1]天津大学化工学院杉山表面技术研究室,天津300072

出　　处：《物理化学学报》2007年第4期493-498,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(50071039;50271046);教育部博士点基金(20030056034)资助项目

摘　　要：采用双槽控电位电沉积法在n-Si(111)基体上以NiFe薄膜为缓冲层制备了[Ni_(80)Fe_(20)/Cu/Co/Cu]_n自旋阀多层膜,并确定了电沉积的工艺条件.利用X射线衍射(XRD)表征了自旋阀多层膜的超晶格结构,研究了NiFe缓冲层对自旋阀生长取向的影响.采用四探针法研究了各子层厚度对自旋阀巨磁电阻效应的影响,通过振动样品磁强计(VSM)测试了自旋阀的磁滞回线.自旋阀的巨磁电阻(GMR)值最初随着铜层厚度的变化发生周期性振荡,Cu层厚度为3.6nm时,GMR达到最大值,随后逐渐减小.随着Co层和NiFe层厚度的增大,GMR值的变化趋势均为先增大后减小.当自旋阀的结构为NiFe(25nm)/[Cu(3.6nm)/Co(1.2nm)/Cu(3.6nm)/NiFe(2.8nm)]_30时,GMR值可达5.4%,对应的磁电阻灵敏度(SV)为0.2%·Oe^(-1),饱和磁场仅为350Oe.[Ni20Fe20/Cu/Co/Cu]. spin-valve multilayers were fabricated onto n-Si（111） substrates covered with NiFe buffer layers by means of double bath potentiostatic electrodeposition. The electrochemical conditions were determined. A well-defined superlattice structure was characterized by high-angle X-ray diffraction, and the influence of NiFe buffer layer upon the orientation of crystalline growth was studied. Magneto-transport properties of the spin valves were investigated by four-probe technique. Hysteresis loops were tested by vibrating sample magnetometer （VSM） at room temperature. With the increase of the Cu layer thickness （tc.）, giant magnetoresistance（GMR） ratio showed a periodical oscillation at first and achieved the maximum at tCu=3.6 nm, then declined gradually. With the increase of the Co and NiFe layer thickness, GMR ratio rose at first, and dropped after the peak point. The maximum room temperature GMR ratio of 5.4% was obtained with a sensitivity up to 0.2%· Oe^-1 and a saturation field of 350 Oe for NiFe（25 nm）/[Cu（3.6 nm）/Co（1.2 nm）/Cu（3.6 nm）/NiFe（2.8 nm）]30 structures.

关 键 词：自旋阀 多层膜 电沉积 巨磁电阻 超品格 

分 类 号：O484.43[理学—固体物理]