formed at all of the interfaces of the ENIG and ENEPIG boards and that the thickness increased with increasing thermal aging time. Moreover, it was found that the IMC formed on the ENEPIG board grew more slowly in comparison with that on the ENIG board. According to the results of the drop test, the ENEPIG board showed a smaller change in reliability in comparison with the ENIG board. Moreover, while cracks occurred inside the P-rich Nilayer formed in the joint in the case of the ENIG board, they occurred inside the inner part of the solder in the case of the ENEPIG board. Accordingly, the ENEPIG surface ﬁnish board shows better reliability rather than the ENIG surface ﬁnish board.
rate (about 0.3 Å/s) and the final thickness were moni- tored by precalibrated quartz oscillators. All the samples were deposited on glass substrate at 300 K on a non- magnetic buffer layer 100 Å thick. The Ni-layer thick- ness t Ni was varied from 14 to 50 Å and that of t Cu were
The first column of Fig. 1 (images (a) to (i)) shows the SEM images of those Ni layers with various thicknesses after the pretreatment process. SEM images in the second column of Fig. 1 show the surface structure of samples identical to those in the first column, after 2 min of CNT synthesis process at 5 Torr and 900 W microwave power, following the pretreatment step. The third column of Fig. 1 shows images of CNTs grown after 20 min of processing time, under similar operating conditions as in the second column. For Ni films thicker than *4 nm, the effect of pretreatment on the catalyst is clearly seen in the first and second columns, as agglomeration and granular structures of the surface formed by a fragmentation and reorganiza- tion of the deposited smooth Nilayer. AFM analysis, shown in Fig. 2, indicates that the films with *2 to *4 nm thick Ni catalyst also have granular structures after pretreatment, although they appear smooth and homoge- nous in the SEM images.
For the multilayer Au/Ni/Cu conductor with a thin Au lay- er, the Au layer quickly dissolves into a molten Sn-base sol- der during soldering, and then the Nilayer is contacted with the solder. As a consequence, the Nilayer is directly reacted with the solder during soldering and solid-state energization heating. As to a phenomenon during energization heating, the solid-state reactive diffusion in the Ni/Sn system was experi- mentally examined using sandwich Sn/Ni/Sn diffusion cou- ples prepared by a diffusion bonding technique in a previous study. 16) In this experiment, the diffusion couples were iso-
Resistivity of PTC electrode keeps constant below 80 °C as same as the tendency of blank electrode, and rises slightly between 80 °C to 90 °C, but when temperature exceeds 90 °C, the impedance increases several tens of times than that of ambient temperature (25 °C). It can be explained that the increasing of PTC-electrode resistivity is caused by the PTC layer which included PTC compound based on PVDF/Ni is highly sensitive to high temperature as M. Kise reported . The increasing trend of PVDF/Nilayer is similar to A. Kono  work that PVDF/Ni composites has nice PTC effect and the transition temperature is below 100 °C with 30 vol.% Ni content. It’s well known that when the temperature of electrodes exceeds 100 °C, many side reactions will happen, such as decomposition of SEI, solvent evaporation, and oxidation reaction between the cathode and the electrolyte  and the safety is uncertain. Therefore it’s certainly essential to shut down those adverse reactions at lower temperature and the PTC layer provides suitable convenience of current-limiting effect.
From figure 3, it is found that there is a tendency for the rising Ni content due to an increasing electrolyte temperature, which is 65.4% at 30 C to 94.8% at 60 C, except for 70 C, the level decreases to 87.2% . The increasing in Ni content indicates that an increase in electrolyte temperature can reduce the viscosity of the solution thereby increasing the ease of mass transport of Ni ions to the Cu cathode. As a result, the rate of formation of Ni deposits at the cathode becomes greater so that the levels increase. In contrast to the specimens resulted from deposition in 70 C electrolyte, because the temperature is too high, the Nilayer is burned and less attached so that Ni levels become decrese. The other thing that happens to Cu, is that because the X-ray energy dispersed has a limited range, the increase in Ni levels will reduce the Cu level too. Therefore 60 C is the best electrolyte temperature for Cu/Ni plating.
Guillén and Herrero investigated on ITO/Ag/ITO multilayer elec- trodes with optical transmittance at blue spectrum of ∼ 60–70% and sheet resistance of 6 /sq . Due to the opaque prop- erties of the metal layer, the light transmittance through the ITO/metal/ITO contact layer decreases as compared to the single ITO thin ﬁlms of ∼ 85% [7,8]. These electrical and optical challenges can be overcome by performing substrate heating during sputtering or post-deposition annealing at speciﬁc heat treatment condi- tions [9–11]. Post-deposition annealing at certain temperature can transform the as grown amorphous ITO into polycrystalline ITO with superior optoelectronics functionality . Some researchers observed an improvement in both the ITO thin ﬁlms and the ITO/Si interface properties with the increasing of annealing temperature up to 300 ◦ C , whereas other group of researchers reported on the improved optoelectronics properties of ITO-based transparent conductive electrodes after post-deposition annealing at tempera- ture of 500 ◦ C and 600 ◦ C .
P25+Ni-SP single layer, and P25+Ni-SP four layers) were measured. The P25+Ni-SP four-layer thin film showed the highest absorptivity, and the P25 single-layer thin film showed the lowest absorptivity. If comparing P25 single-layer and P25 four-layer thin films (black solid line and black dashed line) with P25+Ni-SP single-layer thin film and P25+Ni-SP four-layer thin film (red dotted line and red dashed dotted line), the samples with four layers show higher methylene blue absorptivity in both cases. This result indicates that the surface area of four-layer thin films was significantly improved because of the absence of cracks. Furthermore, there was almost no difference in absorptivity between the P25 four layers and P25+Ni-SP single layer. This is an indication of the effect of Ni-doped powder on the improvement of the thin film surface area.
lic phase was partially formed but most of the solders was composed of Sn as shown in Fig. 10(a). On the other hand, in a specimen heated to 513 K, Ni–Co–Sn phase of which the atomic ratio is 19.9:5.8:74.3 was formed in the joints to consume Sn almost all as shown in Fig. 10(b). From these results, it is obvious that Ni–Co–Sn phases were formed by an exothermic reaction between melted solder and Au/Ni– 20Co plating.
Silicon (Si), the second most abundant element in earth, has been widely used in electronics and solar in- dustries due to its low price and well-developed applica- tion knowledge. To achieve maximized SSA, a wide variety of methods have been proposed to fabricate sili- con nanostructures using top-down or bottom-up approaches, for example, vapor-liquid-sold (VLS) depos- ition, reactive ion etching (RIE), electrochemical etching, or metal-assisted chemical etching [11–14]. Among these techniques, electrochemical etching is chosen to synthesize porous Si (PSi) under an atmospheric and low-temperature environment with controllable thick- nesses and porosities through the etching current and the duration. However, compared with pristine doped wafers, the porous-structured electrode suffers from poor electric conductivities, largely due to surface traps  and deteriorated stability because of its high reactiv- ity caused by enlarged surface area . These shortcom- ings affect the charges inducible in the electrochemical double layers and limit the lifetime of the PSi-based EDLC. Therefore, protection of the electrode and en- hancement of its conductivity are required to improve the capacitive performances of the PSi-based EDLCs. Two-di- mensional structured graphene, a carbon analogue with sp 2 hybridization, possesses excellent electronic and physiochemical properties and chemical stability as well as exceptional structural strength, which are extremely favor- able to enhance electrochemical performances such as high capacities, energy densities, fast charge-discharge rates, and long lifetime for energy storage devices [17, 18]. However, a conventional transfer technique of the gra- phene layer cannot achieve the uniform coating on surface of nanostructures with a higher aspect ratio.
nate the undesired organic constituents such as carbon and sulfur present on the surfaces of the spent catalysts. Then, ferromagnetic Ni is deposited on the surfaces of the PGM particles and/or the catalyst layer using the electroless plating technique. Next, a heat treatment is performed, as needed, in order to enhance the adhesion of the deposited Ni and to pro- mote the alloying of the PGMs with the deposited Ni. As mentioned above, automobile catalysts have complex honey- comb-like structures, and their catalyst layer is highly porous. Nevertheless, it is expected that the plating solution can be effectively supplied to the complex and porous surfaces of the catalysts. Electroless plating on a ceramic usually involves complicated pretreatments of its surface, such as sensitization and activation. However, in the case of automobile catalysts, it should be possible to perform the electroless deposition of Ni without such pretreatments because the PGM particles in the catalyst layer would act as catalysts for the electroless plating process. After the deposition of Ni, the automobile catalyst is crushed and pulverized. Then, the Ni-attached por- tion (i.e., the PGM particles and/or the PGM-containing cat- alyst layer) is magnetically separated based on the ferromag- netic properties of Ni. This process allows the PGMs to be concentrated in the magnetic powder and the ceramic compo- nents (i.e., mainly the ceramic substrate) to be removed in the form of the nonmagnetic powder left behind. It should be noted that the deposited Ni, which is used to concentrate the PGMs, can be employed as a collector metal for the subse- quent pyrometallurgical recycling process. Furthermore, when the PGMs in the magnetic powder are alloyed with Ni in the appropriate amount, they can be extracted efficiently by direct dissolution in an acid.
Numerals inserted with an arrow in Fig. 6, present the number of the C-type layer-units in each repeat-block in the central section of the image. Numerals other than 5 and 6 appeared above and below. The totally non-periodic struc- tures can be observed in the image. Making an average for m at the main part of the image, we obtain that m is approximately equal to 5.25. This value is consistent with the m-value obtained in the simplest model assumed from the electron diﬀraction pattern.
The thermal stability of coatings containing a Re-based diﬀusion barrier layer was investigated by surface and cross-sectional analysis methods. A Re-based barrier layer accompanied by an outer Ni-Cr-Al layer was prepared by electrolytic plating onto a Ni-based superalloy, followed by Cr-pack cementation in vacuum at 1523 K. Vacuum annealing was carried out at 1423 K for 25 h. Another type of coating specimen, with an additional Al reservoir layer on the Re-based barrier layer, was oxidized in air for 25 one-hour cycles at 1423 K. EDXRF, XRD, SEM, EDS and EPMA were used for analysis to evaluate the eﬀects of the heat treatments. It was found that the barrier layer decomposed at high temperature when it was coated with a low-Al Ni-Cr-Al phase, but had good stability when it was adjacent to a high-Al Ni-Cr-Al phase. [doi:10.2320/matertrans.48.127]
in size) have been prepared by freeze-drying tape-casting and developed as solid oxide fuel cell electrodes[42, 43, 47, 68, 69]. The open pores/channels not only facilitate gas diffusion but also function efficiently as catalyst support. In this chapter, for the first time, we have deposited a thin nanoscale catalyst layer on the inner wall surface of Ni- based anode gas diffusion channel via a combination of freeze-drying tape-casting and vacuum-free infiltration. Infiltration has been considered as a strategy to alleviate the issues associated with thermal expansion and conductivity mismatch[86, 109, 110]. Therefore, such a novel combination provides much more freedom to select high performance catalysts even with poor thermal compatibility with the Ni-based anode or with limited electrical conductivity. The continuously graded macro pores/channels with porosity of around 50 vol % and tortuosity factor of ~2[42, 68], are not only beneficial for gas delivery in the electrodes but also for facile solution penetration during infiltration. Through infiltration, ceria solution would first soak in the gas diffusion channel and ceria particles would finally be formed on the surface of the Ni-based channel wall upon drying and combustion. Taking the advantages of the unique microstructure of the Ni- based anode substrate and catalyst infiltration, a thin nanoscale samaria doped ceria (SDC) catalyst layer has been uniformly deposited in the Ni-based anode gas diffusion scaffold. Button cells consisting of Ni-YSZ anode (with and without SDC catalyst layer), thin YSZ electrolyte and (La 0.80 Sr 0.20 ) 0.95 MnO 3-δ -YSZ (LSM-YSZ) cathode have been fabricated
Biomaterials are used in the human body to replace or interact with a living tissue or biological systems. Titanium and its alloys have been extensively used as implant materials in orthopedic and dental surgery due to their excellent corrosion resistance and mechanical properties close to human bone [1-5]. Between Ti alloys, Ni-Ti alloy with a nearly equal atomic ratio of Ni and Ti has been increasingly used in medical and dental applications due to its high corrosion resistance and good biocompatibility [6-8]. Unfortunately, titanium and its alloys are bioinert and easily encapsulated after implanting into the living body by fibrous tissue that isolates them from the surrounding bone [9-11]. Furthermore, the high Ni content in the Ni-Ti alloy is one of the great concerns with regards to its biocompatibility. Because, it has been reported that Ni can be dissolve from Ni-Ti alloy due to the
Two diﬀerent kinds of substrates used in this study were Au/Cu substrates and Au/Ni/Cu substrates with the Au layers of 0.4–0.5 and the Ni layersof 5–7 mm thickness, respec- tively. The Ni and Au layerswere plated with electrolytic method. The thickness of the layers was examined by scanning electron microscopy (SEM) operated at 20 kV. These substrates were then cleaned with acetone and etched in a 10%H 2 SO 4 –90%CH 3 OH solution to remove surface
In gas turbine plants, an increase of the turbine inlet temperature is required in order to improve thermal efﬁciency and to reduce the emission of carbon dioxide. However, at high temperature, damage and failure of the nickel (Ni)-based superalloy gas turbine blades, such as melting, creep, and high temperature oxidation can be occurred. To prevent these problems, the surface temperature of these gas turbine blades must be protected by thermal barrier coatings (TBCs). To obtain low thermal conductivity, the TBCs are generally applied to a superalloy substrate and are composed of a metallic bond coat and a ceramic top coat. Normally, the fabrication of the TBCs involves the application of a MCrAlY (M = Ni, Fe, Co, or their combination) bond coat to a Ni-based superalloy substrate, followed by a top coat of yttria-stabilized zirconia (YSZ). 17)
PVC/CS-co-Ir Ni oxide nanoparticles composite membrane was produced by the casting technique. Prior to modification, membranes were dipped in distilled water in order to remove any pollutant. The prepared heterogeneous cation exchange membrane was clamped between two glassy frames. An aqueous phase containing chitosan (cationic layer), acetic acid, poly ethylene glycol (pore former) and iron-nickel oxide nanoparticles (additive) was poured on top of the prepared membrane and rolled by a soft roller to eliminate any bubble and make a uniform area. It is worth mentioning that the modifier solution was mixed vigorously at room temperature and sonicated to obtain homogenously dispersed solution during the modifier preparation. After that, the membrane was dried at ambient temperature for 24 h until solidification was completely done. Then composite membranes were pretreated by immersing in 0.5 M NaCl solution. The composition of the used modifier solution in the fabrication of the composite membrane is shown in Table 2. The modifier film was deposited on the top surface of the prepared membrane.
The (Ni, Al)/AlN nanoparticles were fabricated by the arc-discharge method and confirmed to have an unique tadpole-shape nanostructure of (Ni, Al) metallic head and AlN tail. The nanoparticles present strong dielectric loss in the frequency range of 16–18 GHz, which is considered as the result of enhanced interfacial and dipolar polarization, relating to the anisotropic shape of (Ni, Al)/AlN nanoparticles. The maximum reflection loss reaches −31.6 dB at 17 GHz for the absorber in a thin thickness of 1.4 mm. As an additive for microwave absorbent, the tadpole-shaped (Ni, Al)/AlN nanoparticles can complement the deficiencies of high frequency loss to the traditional absorbents, and moreover, the chemical stability of aluminum nitride would allow the nanocomposite working in severe environmental conditions beyond the endurance of pure metals.
beta source with two active sides, would also be helpful in order to maximise the conversion of beta energy in electrical energy. Such design improvements will be considered for future generations of radioisotope microbatteries from our laboratory. Next generation of In 0.5 Ga 0.5 P 63 Ni radioiso tope