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利用金属掩模法优化了制备磁性隧道结的实验和工艺条件,金属掩模的狭缝宽度为100 μm. 采用4 nm厚的Co75Fe25为铁磁电极和10或08 nm厚的铝氧化物 为势垒膜, 直接制备出了室温隧穿磁电阻(TMR)为30%—48%的磁性隧道结,其结构为Ta(5 nm)/Cu(25 nm)/Ni79Fe21(5 nm)/Ir22Mn78(10 nm)/ Co75Fe25 (4 nm)/Al(08 nm)-O/Co75Fe25(4 nm)/Ni79Fe 21(20 nm)/Ta(5 nm).同时,利用刻槽打孔法和去胶掀离法两种光刻技术并结合Ar离子束刻蚀及化学反应刻 蚀,制备出面积在4 μm×8 μm—20 μm×40 μm、具有室温高TMR和低电阻的高质量磁性 隧道结.300 ℃ 退火前后其室温TMR可分别达到22% 和50%.研究结果表明,采用光刻中的刻 槽打孔或去胶掀离工艺方法制备的小尺寸磁性隧道结,可用于研制磁动态随机存储器和磁读 出头及其他传感器件的磁敏单元.
关键词:
磁性隧道结
隧穿磁电阻
金属掩模法
光刻法 相似文献
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273.15K时LiCl-Li2SO4-H2O体系热力学性质的等压研究 总被引:2,自引:0,他引:2
0℃下用改进的等压设备和改进的实验方法测定了纯水溶液(LiCl 0.5~9.2mol·kg-1,Li2SO40.3~2.5mol·kg-1)以及混合水溶液(离子强度0.5~9.5mol·kg-1)的水活度和渗透系数.该体系的等水活度线与Zdanovskii规则非理想混合溶液表达式的标准偏差为0.0088,当Li2SO4溶液达到饱和后,用Zdanovskii规则扩展式计算,标准偏差为0.0027.根据Pitzer离子相互作用模型对实验数据进行了理论分析,用本文和不同来源的文献数据拟合求取了0℃下该体系的Pitzer纯盐参数和混合参数,计算值与实验值相吻合. 相似文献
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以Gd2O3、K2CO3、MoO3为原料,采用高温熔盐法,合成了一个含钾的稀土钼酸盐KGd(MoO4)2。通过X射线单晶衍射法测定了它在室温下的晶体结构,并测定了它的光学性质。结构分析表明它属于三斜晶系,空间群为P1,a=0.529 23(6)nm,b=0.692 10(6)nm,c=1.068 89(7)nm,α=75.79(8)°,β=76.79(5)°,γ=67.60(4)°,Z=2,R1(all data)=0.025 8。结构中的K和Gd原子位于各自的晶体学位置,不存在调制结构的现象。此外,我们用得到的晶体学数据,通过密度泛函理论研究了化合物的能带结构、态密度、介电常数,其结果和实验数据相吻合。 相似文献
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One new chiral zeolitic rho-type metal-organic framework [Cd(L-ala)2]n(1) has been successfully synthesized based on L-alanine chiral ligand, which demonstrates the feasibility of fabricating MOF that integrates the 4-connected zeotype topology by the employment of L-alanine. To the best of knowledge, it's the first report that metal-organic framework based on amino acid features the chiral zeolitic rho-type structure. Compound 1 was characterized by X-ray powder diffraction, elemental analysis and single-crystal X-ray diffraction. Crystal data: C_6 H_9 CdN_2 O_4, Mr = 285.55, cubic system, space group I432, a = 24.0795(6), V = 13961.9(10) ?~3, Z = 48, Dc = 1.630 Mg/m~3, F(000) = 6672, μ(Mo Kα) = 1.865 mm~(-1), S = 1.058, R = 0.0271 and wR = 0.0312 for 1870 observed reflections with I 2σ(I). The circular dichroism(CD) property of compound 1 was also investigated. 相似文献
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A series of Tb-doped solid solutions PbGd_(1-x)Tb_xB_7O_(13)(x = 0~1) were synthesized by high-temperature solid state reaction method. The luminescence properties were investigated under UV(274 nm) and near-UV(372 nm) excitation. The emission spectrum by 274 nm exciting reveals a charge-transfer between Gd~(3+) and Tb~(3+) ions. Under near-UV light(372 nm) excitation, PbGd_(1-x)Tb_xB_7O_(13):x Tb~(~(3+)) exhibits intense green emission centered at 543 nm due to the ~5D_4→~7F_5 transition of Tb~(3+) activator. The optimum doping concentrations were found to be x = 0.8 with the quantum efficiency of 35%. One may expect that PbGd_(1-x)Tb_xB_7O_(13) has the potential to be used as a green phosphor activated by near near-UV light. 相似文献
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We present a finite temperature theory for bias-dependent tunnelling in ferromagnetic tunnelling junctions. The effects of the barrier width d on the tunnelling magnetoresistance (TMR) and its sign change behaviour are discussed with this theory. Numerical results show that both the zero-bias TMR and the critical voltage Vc at which the TMR changes its sign decrease with the increasing barrier width for a considerably thick barrier junction. Furthermore, it is found that a minimum exists in the curve of Vc versus d if a composite junction is under oxidized. 相似文献