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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.

Magnetite nanocrystals of 2–4 nm were synthesized by a chemical coprecipitation method, by which the particle size was controlled by the reaction temperature. The nanocrystals were investigated by XRD, TEM/HRTEM, VSM and SQUID. It is found that the nanocrystals reveal well-defined superparamagnetic behavior before and after annealing, while the observation of the distinct lattices manifest the high crystallinity of the ultrasmall particles.

We synthesized monodisperse CoPt nanoparticles by a modified polyol process, in which Co(acac)3 and Pt(acac)2 were co-reduced by a diol in the presence of PVP surfactants at high temperature (acac = acetylacetonate, PVP = polyvinylpyrrolidone). It is found that the CoPt nanoparticles assume a face-centered cubic phase and possess high crystallinity, with a particle size of 5.3 nm and a tight size distribution. The nanoparticles show superparamagnetism in the as-synthesized state and become ferromagnetic after annealing. The magnetization process of the nanoparticles prior to heat treatment was analyzed by the Langevin equation and their effective magnetic particle size was thus obtained, in close approximation to the results from the XRD and TEM observation.

We report the synthesis and characterization of monosized Eu-doped ZnO nanocrystals via a nanoemulsion process as a function of the doping ratio. The structure, optical, and magnetic properties of the nanocrystals are investigated by XRD, TEM, PL spectrometry, and physical property measurement system. The nanocrystals as prepared show high crystallinity and tight particle size distributions with the diameters of ∼ 10 nm. The doped samples clearly exhibit the 5D0→7FJ transition emission due to the presence of the Eu3+ ions. Meanwhile, the magnetic responses demonstrate the temperature dependence and change with dopant concentration.