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A double-barrier magnetic tunnel junction (DMTJ) comprising an amorphous ferromagnetic NiFeSiB was investigated to reduce bias voltage dependence of tunneling magnetoresistance (TMR) ratio. The typical DMTJ structures were Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/free layer 7/AlOx/CoFe 7/IrMn 10/Ru 60 (in nanometers). Various free layers such as CoFe 7, NiFeSiB 7, CoFe 3.5/NiFeSiB 3.5, and NiFeSiB 3.5/CoFe 3.5 were prepared and compared. The NiFeSiB-used DMTJ shows a low root-mean-square surface roughness of 0.17 nm, a resistance of about 860 Ω, a Vh (voltage where the TMR ratio becomes half of its nonbiased value) of 1.1 V, and a high junction breakdown voltage of 2.0 V. The DMTJ with an amorphous NiFeSiB free layer offers smooth surface roughness resulting in reduced interlayer coupling field and bias voltage dependence. [ABSTRACT FROM AUTHOR]

Au-doped CoPt nanowires were prepared in anodized aluminum oxide (AAO) nanotemplates by electrodeposition and the doping effects on their microstructure and magnetic properties were investigated. Dependent on the deposition conditions, the CoPtAu nanowires can have the cubic or tetragonal phase. The magnetic measurements indicate that the nanowires demonstrate ferromagnetic behavior, showing the easy axis along the direction of the nanowires and strong enhancement in coercivity and squareness prior to annealing, whereas the optical measurements reveal plasmon resonances characteristic of nanostructured Au. [ABSTRACT FROM AUTHOR]

Analytical electron microscopy (AEM) was used to examine the initial interfacial reaction layers between a eutectic Sn-3.5Ag solder and an electroless nickel-immersion gold-plated (ENIG) Cu substrate during reflow at 255 °C for 1 s. AEM confirmed that a thick upper (Au,Ni)Sn2 layer and a thin Ni3Sn4 layer had formed through the reaction between the solder and ENIG. The amorphous electroless Ni(P) plated layer transformed into two P-rich Ni layers. One is a crystallized P-rich Ni layer, and the other is an intermediate state P-rich Ni layer before the crystallization. The crystallized P-rich layer consisted of Ni2P and Ni12P5. A thin Ni2P layer had formed underneath the Ni3Sn4 layer and is believed to be a predecessor of the Ni2SnP ternary phase. A Ni12P5 phase was observed beneath the Ni2P thin layer. In addition, nanocrystalline Ni was found to coexist with the amorphous Ni(P) phase in the intermediate state P-rich Ni layer. [ABSTRACT FROM AUTHOR]