• Journal of the Korean Society for Heat Treatment
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• v.21 no.5
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• pp.235-243
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• 2008

Ni-C composite films were prepared using a combination of microwave plasma CVD and ion beam sputtering deposition working in a codeposition way. The structure of these films was characterized by energy-dispersive X-ray diffraction (EDXRD), transmission electron microscopy (TEM) and Raman spectroscopy. It was found that a nickel carbide phase, $Ni_3C$ (hcp), formed as very fine crystallites over a wide temperature range when Ni-C films were deposited at low $CH_4$ flow rates. The thermal stability of this nonequilibrium carbide $Ni_3C$ was also studied. As a result, the $Ni_3C$ carbide was found to decompose into nickel and graphite at around $400^{\circ}C$. With high $CH_4$ flow rates (> 0.2 sccm), the structure of the Ni-C films became amorphous. The formation behavior of the carbide and amorphous Ni-C phases are discussed in relation to the electrical resistivity of the films.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2158-2162
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• 2010

Studies on the molecular construction and structures of $M(NO_3)_2$ (M = Cu(II), Ni(II)) complexes with 1,2-bis(dimethyl-3-pyridylsilyl)ethane (L) have been carried out. Formation of each molecular skeleton appears to be primarily associated with a suitable combination of bidentate N-donors of L and coordinating nature of octahedral metal(II) ions: [$Cu(NO_3)_2(L)_2$] yields a 2-dimensional sheet structure consisting of 44-membered $Cu_4L_4$ skeleton whereas $[Ni(L)_2(H_2O)_2](NO_3)_2$ produces an interpenetrated 3-dimensional structure consisting of 66-membered cyclohexanoid ($M_6L_6$) skeleton. The Cu(II) ion prefers nitrate whereas the Ni(II) ion prefers water molecules as the fifth and the sixth ligands.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.67-73
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• 2021

Nickel-rich lithium nickel-cobalt-manganese oxides (NCM) are viewed as promising cathode materials for lithium-ion batteries (LIBs); however, their poor cycling performance at high temperature is a critical hurdle preventing expansion of their applications. We propose the use of a functional electrolyte additive, triphenyl phosphate (TPPa), which can form an effective cathode-electrolyte interphase (CEI) layer on the surface of Ni-rich NCM cathode material by electrochemical reactions. Linear sweep voltammetry confirms that the TPPa additive is electrochemically oxidized at around 4.83 V (vs. Li/Li+) and it participates in the formation of a CEI layer on the surface of NCM811 cathode material. During high temperature cycling, TPPa greatly improves the cycling performance of NCM811 cathode material, as a cell cycled with TPPa-containing electrolyte exhibits a retention (133.7 mA h g-1) of 63.5%, while a cell cycled with standard electrolyte shows poor cycling retention (51.3%, 108.3 mA h g-1). Further systematic analyses on recovered NCM811 cathodes demonstrate the effectiveness of the TPPa-based CEI layer in the cell, as electrolyte decomposition is suppressed in the cell cycled with TPPa-containing electrolyte. This confirms that TPPa is effective at increasing the surface stability of NCM811 cathode material because the TPPa-initiated POx-based CEI layer prevents electrolyte decomposition in the cell even at high temperatures.

• Polymer(Korea)
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• v.26 no.5
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• pp.551-558
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• 2002

It was observed that adsorption characteristics of sulfonated fabric ion-exchanger for separating nickel ion from electroplating rinse water. Swelling ratio was increased by increasing degree of sulfonation and polarity of solvent. Ion-exchange capacity was also increased by increasing degree of sulfonation and showed 3.38 meq/g at 16% sulfonated ion-exchanger. There was little effects of pH. Adsorption equilibrium was attained within 10 min, and adsorption rate was 7.5 mg/min. Adsorption capacity was not changed after 7 cycles of regeneration process. Regeneration adsorption capacity was slightly decreased to 2.01 meq/g. It confirmed that durability of sulfonated fabric ion-exchanger was suitable for adsorption process. Adsorption equilibrium time was linearly increased by increasing L/D and adsorption capacity showed the ion exchange capacity within the range of 2.71 ∼ 3.01 meq/g in continuous process. Design of adsorption column could be possible for L/D<2. Under constant L/D condition, there is no little pH effect when rinse water is acidic solution, and operation condition of adsorption process was optimized under pH 5.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.911-916
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• 2015

In the nano/micro scale, material properties are dependent on the size-scale of a structure. However, conventional micro-scale tensile tests have limitations to obtain reliable values of nano-scale material properties owing to residual stress and elastic slippage in the gripping/aligning process. The indenter-driven nano-scale tensile test provides prominent advantages simple testing device, high-quality nano-scale metallic specimen with negligible residual stress. In this paper, two-types of specimens (a specimen with multi-testing parts and a specimen with a single-testing part) are discussed. Focused ion beam (FIB) is employed to fabricate a nano-scale specimen from a thin nickel film. Using the specimen with a single-testing part, we obtained a nano-scale stress-strain curve of electroplated nickel film.

• Journal of Electrochemical Science and Technology
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• v.6 no.4
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• pp.116-120
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• 2015

Lithium diffusivity of fluorine-free and -doped tin-nickel (Sn-Ni) film model electrodes with improved interfacial (solid electrolyte interphase (SEI)) stability has been determined, utilizing variable rate cyclic voltammetry (CV). The method for interfacial stabilization comprises fluorine-doping on the electrode together with the use of electrolyte including fluorinated ethylene carbonate (FEC) solvent and trimethyl phosphite additive. It is found that lithium diffusivity of Sn is largely dependent on the fluorine-doping on the Sn-Ni electrode and interfacial stability. Lithium diffusivity of fluorine-doped electrode is one order higher than that of fluorine-free electrode, which is ascribed to the enhanced electrical conductivity and interfacial stabilization effect.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.409-415
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• 1988

In this study, an aniline modified Bakelite-A resine was synthesized by polymerizing phenol, formaldehyde and aniline. Structural properties of the polymer were examined by IR spectroscopy, elemental analysis and vapour pressure osmometry. By visible spectroscopy, it was found that nitrogens of amine groups in the polymer are strongly coordinated to Ni(Ⅱ). Also a nitrate ion-selective PVC membrane electrode based on the polymer-Ni(Ⅱ) complex as ion carrier was preparaed. The electrode gave a linear response with a Nernstian slope within the concentration range $10^{-1}$ M∼$10^{-4}$M $KNO_3$.

• Applied Chemistry
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• v.16 no.1
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• pp.25-28
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• 2012

A determination method of cyanide ion (CN^-) using nickel complexation reaction by continuous monitoring system. The mechanical parameters and chemical conditions of the complexation reaction were investigated prior to application of continuous monitoring system for determination of cyanide. On the optimized conditions, the calibration curve was linear over the range from 5.0×10^-6 to 1.0×10^-4 M. In this range, 2.40% of the reproducibility (RSD, n=3) was obtained. The limit of detection (3σ/s) was calculated to be 1.8×10^-6 M.

• Journal of the Korean Ceramic Society
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• v.23 no.2
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• pp.43-49
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• 1986

By simple substitution of divalent cobalt nickel copper ion in the calcium-fluorapatite the ability to produce color was explored. To determine the solubility limit of cobalt nickel copper in the calcium-fluorapatite and the absorption spectrum with the addition of each transition elements XRD and visible range Spectroscopy were emp-loyed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.262-265
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• 1998

Nickel Plating improves on the corrosion resistance of materials in acid and moisture environment. In this study, we investigated the surface morphology, XRD patterns and pole figures of the various types of Ni electrodeposits. The texture of Ni electrodeposits changed from <100> to <111> through <110> with increasing the temperature of electrolyte and the concentration of nickel ion. The texture of Ni electrodeposits changed from <100> to <100> after annealing. Also the <110> texture changed to the <√310> texture after annealing.