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1
Saifulin, M. M., A. A. Mashentseva, and M. V. Zdorovets. "Template Synthesis and Composition of Bimetallic Co/Ni Nanostructures Arrays." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35265.
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Nanostructures, based on nickel and cobalt, are promising for the development of magnetic metamaterials. Magnetic nanotubes have become a symbol of new and fast developing research area of nanotechnology. Their potential applications are in many fields, including electronics, catalysis, magnetism and electrochemistry. The template method is commonly used to prepare this kind of materials. The paper describes magnetic nanotubes and nanowires preparation method, based on electrochemical deposition in track etched membranes. Various electrolytes have been used to obtain nanostructures of different cobalt and nickel compositions. We have obtained the ordered arrays of bimetallic cobalt/nickel nanostructures with sizes from 70 to 600 nm.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35265
2
Silva, Charles da Rocha. "Estudo das interações magnéticas em nanofios de Ni obtidos por eletrodeposição AC." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29022008-105215/.
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Foram feitos estudos das propriedades magnéticas e estruturais em nanofios de níquel em uma lâmina de alumínio. As amostras foram obtidas através da anodização em duas etapas, seguida de uma eletrodeposição AC. Foi verificado que o aumento do potencial usado nas anodizações acarretam em um aumento do tamanho dos grãos cristalinos de níquel e dos diâmetros dos nanofios. O tamanho dos grãos de níquel e dos diâmetros dos nanofios variaram, respectivamente, entre 10 a 20 nm e 30 a 50 nm. As amostras apresentam alta anisotropia de forma, com coercividade entre 565 a 725 Oe. As interações magnéticas foram estudadas através das curvas `delta´M, estas mostraram que as interações desmagnetizantes são dominantes nestes sistemas. O modelo de Stoner-Wohlfarth, acréscido de um termo de interação foi utilizado para simular e interpretar o comportamento magnético dos nanofios. Através dos resultados numéricos e experimentais foi verificado que a componente reversível (Mrev) da magnetização independe do estado inicial do sistema, diferentemente do comportamento para a componente irreversível (Mirr). Através da análise das curvas de Mrev(Mirr)Hi , provenientes dos resultados numéricos e experimentais, foi verificado que existe um forte indicativo quanto ao modo de inversão da magnetização por curling, para nanofiosStudies of magnetic and structural properties of nickel nanowires deposited on nanoporous alumina membranes were carried out. The samples were obtained by a two-step anodization, followed by an AC electrodeposition. It was noted that the diameters of the nanowires and the crystalline grain size of the deposited nickel increase with the anodization voltage. The mean diameters and the grain sizes varied from 10 to 20 nm and from 30 to 50 nm, respectively. The samples exhibited a strong shape anisotropy, with coercivities between 565 and 725 Oe. Magnetic interactions were studied via `delta´M curves, which showed that the dominant interactions are rather demagnetizing in these systems. An interacting Stoner-Wohlfarth model was developed to simulate and reproduce the magnetic behavior of the nanowires. From the comparison between numerical and experimental results (which exhibit excellent agreement), it was noted that reversible components of magnetization (Mrev) do not depend on the initial state of the system, whereas irreversible components (Mirr) do. From the analysis of Mrev(Mirr)Hi curves of numerical and experimental results, it was noted that there is strong evidence for the curling magnetization reversal mode for these systems
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Bukharaev, A. A., N. I. Nurgazizov, D. A. Biziaev, A. P. Chuklanov, and T. F. Khanipov. "Current-induced Phase Transition in Ni Nanowires." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35343.
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The single ferromagnetic Ni nanowires connecting two contact pads on the silicon oxide surface were
fabricated using the scanning probe nanolithography technique based on the nanoindentation of
polymethylmethacrylate resist and lift-off process. Wires with height from 9 to 26 nm, wide from 200 to
500 and length from 5 to 13 m were obtained. The atomic and magnetic force microscopy was used to
study the morphology and domain structure of the obtained nanowires. Multidomain and single-domain
structures depending on the width of the nanowires were observed. Current-induced phase transition from
ferromagnetic to paramagnetic state in the Ni nanowires was observed when studing of current-voltage
characteristics of such nanostructures. This phenomenon is explained by the Joule heating of ferromagnetic
Ni nanowires by the high-density current over Curie temperature.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35343
4
Li, Yanguang. "Nanostructured Materials for Energy Applications." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275610758.
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El, Kousseifi Mike. "Ni silicide contacts : Diffusion and reaction in nanometric films and nanowires." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4349.
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Cette thèse porte sur l'étude des phénomènes qui se produisent lors de la réaction métal-silicium (siliciuration) en couches minces et dans des nanofils. En effet, les phénomènes tels que la germination, la croissance latérale, la croissance normale et la diffusion doivent être compris pour réaliser les contacts des futurs dispositifs de la microélectronique. La comparaison entre la siliciuration en couches minces et dans les nanofils est l'un des principaux aspects de ce travail. La distribution atomique en 3D des éléments chimiques dans les différentes siliciures de Ni a été obtenue par sonde atomique tomographique (SAT). Pour permettre l'analyse par SAT de différents types des nanofils à base de silicium, plusieurs méthodes originales de préparation des échantillons par faisceau d'ions focalisés ont été développées et testées. D'autre part, des mesures in situ et en temps réel de diffusion réactive par diffraction de rayons X ont permis de mettre en évidence l'importance de la germination dans la formation des phases et de déterminer les cinétiques de formation des siliciures de Ni allié en Pt, notamment des régimes de réaction aux interfaces et de croissance latérale. La forme caractéristique associée à la croissance latérale a été déterminée par des analyses ex situ de microscopie électronique en transmission et comparée aux modèles existants. La détermination par SAT de l'espèce qui diffuse majoritairement donne aussi des indications sur les mécanismes de formation des phases et de relaxation des contraintes dans les siliciuresThis thesis focuses on the phenomena that occur during the reaction between metal and silicon (silicide) on thin films and nanowires. Indeed, phenomena such as nucleation, lateral growth, normal growth and diffusion must be understood to make contacts for future microelectronic devices. The comparison between the silicide formation on thin films and nanowires is one of the main aspects of this work. Atomic distribution in 3D for the elements in different Ni silicide phase was obtained by atom probe tomography (APT). To enable the analysis of different types of silicon nanowires by APT, several original methods for sample preparation by focused ion beam has been developed and tested. On the other hand, in situ and real-time analysis by X-ray diffraction during the reactive diffusion helped to highlight the importance of the nucleation of a phase and to determine the kinetics of formation of Ni(Pt) silicides, including the reaction on the interfaces and the lateral growth. The characteristic shape associated with the lateral growth was determined by ex-situ transmission electron microscopy analyzes and was compared with the existing theoretical models. Moreover, the determination of the fastest diffusing species by APT provided information on the mechanisms of phase formation and stress relaxation in the silicide
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Böhnert, Tim [Verfasser], and Kornelius [Akademischer Betreuer] Nielsch. "Magneto-thermopower and Magnetoresistance of Co-Ni Alloy and Co-Ni/Cu Multilayered Nanowires. / Tim Böhnert. Betreuer: Kornelius Nielsch." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2014. http://d-nb.info/1052996698/34.
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Silva, Elvis Lira da. "Propriedades estruturais e magnéticas de nanofios de Ni e Co." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278291.
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Orientadores: Marcelo Knobel, Daniela ZanchetDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Os arranjos de nanofios magnéticos tem atraído um interesse considerável da comunidade científica, motivado principalmente pela sua utilização como sistemas-modelo e na possível aplicação em mídias magnéticas de alta densidade de informação. O comportamento magnético macroscópico desses sistemas é fortemente dependente das anisotropias magnéticas efetivas (determinadas principalmente pelas contribuições das anisotropias de forma, magnetocristalina e magnetoelástica). Neste trabalho realizamos um estudo completo das propriedades magnéticas de nanofios magnéticos de Ni e Co, variando o comprimento dos nanofios e a temperatura das amostras. Os nanofios são obtidos por eletrodeposição em nanoporos de membranas de alumina preparadas por um duplo processo de anodização em substratos de alumínio. A caracterização estrutural dos nanofios foi feita por microscopia eletrônica de varredura de alta resolução e microscopia de força magnética e revela que os arranjos de nanofios estão organizados em uma rede hexagonal onde possuem diametros de aproximadamente 35 nm e a distância entre os nanofios de aproximadamente 105 nm. O comprimento dos nanofios varia de aproximadamente 560 nm até 2250 nm. Observamos uma mudança do eixo fácil de magnetização da direção paralela ao eixo dos nanofios na temperatura ambiente para direção perpendicular ao eixo dos nanofios em baixas temperaturas. Analisamos a dependência da remanência reduzida e da coercividade em relação à temperatura e verificamos que as amostras apresentam uma temperatura de cruzamento entre as remanências reduzidas com campo aplicado paralela e perpendicularmente ao eixo dos nanofios, que varia de acordo com o comprimento dos nanofios. Interpretamos nossos resultados em termos de uma competição entre a anisotropia de forma, que tende orientar a magnetização na direção paralela ao eixo dos nanofios, e uma anisotropia dependente da temperatura, que tenta alinhar a magnetizaçao na direção perpendicular ao eixo dos nanofios. O mecanismo utilizado para tentar explicar de maneira qualitativa os resultados que observamos, ao diminuirmos a temperatura da amostra, origina-se da tensão provocada pela alumina sobre os nanofios, em decorrência dos diferentes coeficientes de expansão térmica desses materiais, que induz uma anisotropia magnetoelástica perpendicular ao eixo dos nanofios
Abstract: Arrays of magnetic nanowires have attracted considerable interest, mainly motivated by their use as model systems and by possible applications in high-density magnetic information storage. The macroscopic magnetic behavior of such systems is strongly dependent on the effective magnetic anisotropy (mainly determined by shape and crystalline contributions). In this work, we carry out a systematic study of the magnetic properties on highly-ordered magnetic arrays of Co and Ni nanowires as functions of length of the nanowires and temperature. Nanowires were obtained by electrodeposition into nanopores of alumina membranes prepared by a two-step anodization process from pure aluminium. Structural studies were performed by high resolution scanning electron microscopy and magnetic force microscopy. The images revealed uniform arrays of nanowires with diameter of 35 nm, and with hexagonal symmetry arrangement with lattice constant (or inter-nanowire distance) of 105 nm. The nanowires length varies between 560 nm and 2250 nm. We observed a change in the magnetic easy axis from parallel to the axis wires at room temperature to transverse to the wire axis at low temperatures. We analysed the temperature dependence of the reduced remanence and coercive field we verified that the samples present a crossover temperature of reduced remanence with magnetic field applied both perpendicular and parallel to the nanowires axis that varies with nanowires length. We interpreted our results in terms of a competition between the shape anisotropy of the wires, which tends to align the magnetization along the wires axis and the temperature dependent magnetic anisotropy, which tends to orient the magnetization transverse to the wires axis. The mechanism which can qualitatively explain the observed results as a function of temperature is an induced anisotropy of magnetoelastic origin transversal to the nanowires axis, caused by strains and stresses, due to the different thermal expansion coefficient of nanowires and the alumina matrix, respectively
Mestrado
Materiais Magneticos e Propriedades Magneticas
Mestre em Física
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Peixoto, Thiago Ribeiro Fonseca. "Análise FORC em nanofios de Ni e Co e excitação de mágnons de superfície em filmes de O-Fe/W(001) via SPEELS." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26012011-124128/.
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Estudamos o comportamento estático e os mecanismos de inversão da magnetização de arranjos auto-organizados de nanofios de Ni e Co com alta anisotropia de forma. Os arranjos são obtidos a partir da anodização em dois passos de lâminas de Al e subseqüente eletrodeposição do metal magnético. Sua caracterização estrutural é realizada por microscopia eletrônica de varredura, microscopia de força atômica e magnética e difração de raios X. Seu comportamento magnético é estudado a partir da medida de curvas de inversão de primeira ordem (FORCs) a temperatura ambiente, via magnetometria SQUID ou de amostra vibrante. A análise FORC consiste na construção de uma mapa da resposta magnética do material a partir dos dados experimentais e pode ser interpretado a partir da analogia direta com o modelo de histerese de Preisach. Apresentamos resultados da influência dos diâmetros dos nanofios e do ângulo do campo externo aplicado em relação ao eixo de anisotropia sobre as principais características dos diagramas FORC. Estudamos também a dinâmica de spins em superfícies de O-Fe/W(001) através de espectroscopia por perda de energia de elétrons spin-polarizados (SPEELS). As amostras consistem em 30 monocamadas atômicas de Fe crescidas sobre um monocristal de W(001), via epitaxia por feixe molecular a temperatura ambiente. Subseqüentemente, a amostra é exposta a 5 langmuirs de O2 e sofre um suave annealing a 500 K. A estrutura e a pureza da amostra são analisadas por difração de elétrons de baixas energias e espectroscopia de elétrons Auger. A caracterização magnética é realizada por magnetometria por efeito Kerr magneto-óptico, resultando num filme com alta magnetização remanente no plano. Os espectros de SPEELS revelam uma rica profusão de picos inelásticos tipo spin-flip e nãospin-flip, que exibem clara dispersão ao longo de toda a zona de Brillouin de superfície. Os resultados são atribuídos a modos de superfície de fônons e mágnons (ondas de spin), de acordo com resultados da literatura e com modelos teóricos atuais.We study the static behavior and the mechanisms of magnetization reversal of arrays of self-organized Ni and Co nanowires with high shape anisotropy. The arrays are obtained by two-step anodization of Al foils and subsequent electrodeposition of the magnetic metal.Their structural characterization is obtained by scanning electron microscopy, atomic and magnetic force microscopy and X-ray diffraction. Their magnetic behavior is studied from the measurement of first order reversal curves (FORCs) at room temperature, via SQUID or vibrating sample magnetometry. The FORC analysis method consists in building a map of the magnetic response of the material from the experimental data and it can be interpreted from the direct analogy with the Preisach model of hysteresis. We present results of the influence of the diameter of the nanowires and the angle of the applied external field in relation to the anisotropy easy-axis on the main features of the FORC diagrams. We also study the spin dynamics of O-Fe/W(001) surfaces through spin-polarized electron energy loss spectroscopy (SPEELS). The samples consist of 30 atomic monolayers of Fe grown on a W(001) single crystal via molecular beam epitaxy at room temperature. Subsequently, the samples are exposed to 5 langmuirs of O2 and suffer a mild annealing at 500 K. The structure and purity of the samples are analyzed by low-energy electron diffraction and Auger electron spectroscopy. The magnetic characterization is performed by magneto-optical Kerr effect magnetometry, resulting in films with high remanent in-plane magnetization. SPEEL-spectra reveal a rich profusion of inelastic spin-flip and non-spin-flip peaks, which exhibit clear dispersion for wave vectors throughout the whole surface Brillouin zone. The results are attributed to surface modes of phonons and magnons (spin waves), in accordance with the literature and with current theoretical models.
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Miguel, Federico Luis Verfasser], and Frank [Akademischer Betreuer] [Mücklich. "Design and characterisation of Ni-matrix nanocomposite films reinforced with Ag-coated SnO2 nanowires for electrical contact applications / Federico Luis Miguel. Betreuer: Frank Mücklich." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2016. http://d-nb.info/1104733366/34.
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Huang, Ciou-yu, and 黃秋玉. "Studies of electroplating Ni-film and Ni-nanowire in the supercritical carbon dioxide." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99111051813347681830.
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碩士國立中正大學
化學工程所
95
This study is to investigate the characteristic of nickel electroplating in supercritical carbon dioxide (SC-CO2) electroplating process, and to apply this technology to produce Ni-nanowires in anodic aluminum oxide template. It is found that the Ni-film is polycrystalline structure and grain size of the Ni-film decrease with increasing pressure under SC-CO2 electroplating. The reasons could be attributed to: (i) pressure can induce nucleation rate and (ii) the emulsified electrolyte by SC-CO2 acts like pulsation electroplating, leading to a decrease in grain size. In addition, because fine grain size and reduce porosity of the Ni-film under SC-CO2 electroplating. The hardness of the Ni-film in the pressure 10.2MPa to reach 8.29GPa and is about four-time higher than that by ambient electroplating (2GPa). Due to SC-CO2 having the advantages of low surface tension and high mass transfer, the electrolyte can be brought into nanopores, leading to an enhancement of the Ni-nanowire filling rate in anodic aluminum oxide template. Ni-nanowire and Ni-film is like polycrystalline structure and also decreases with increasing pressure. Both of produced Ni-film and Ni-nanowire have the same decreasing trend in coercive field and squareness ratio as increasing pressure.
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Hong, Yan-ling, and 洪燕玲. "Fabrication of ordered AAO template and Ni nanowire arrays." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/27079261244210199301.
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碩士國立中央大學
化學工程與材料工程研究所
96
As the critical dimensions for advanced devices continue to scale towards the nanometer regime, one-dimensional (1-D) metal nanowires have attracted much attention due to their potential applications in advanced microelectronic and magnetic devices. However, the conventional methods used to fabricate periodic nanowires arrays are usually high-cost consuming and low output efficiency. Therefore, this study mainly focused on the synthesis of large-scale nickel metal nanowires at low-cost and high-throughput without complex lithography. To fabricate the size-tunable Ni metal nanowire arrays, the anodic alumina oxide (AAO) templates with 2-D periodic nanopore structures were firstly prepared by the two-step anodizing process. In this work, the pore sizes of AAO templates can be tuned from 20-50 nm by varying the component of electrolyte, the processing temperature, and the applied anodic voltage. Under controlled electrodeposition conditions, a large amount of pure Ni metal nanowires were successfully synthesized by using the AAO template technique. The diameters and lengths of the as-synthesized Ni nanowires were measured to be about 20-50 nm and 60-67 ?m, respectively, corresponding to the pore sizes and thickness of AAO templates. Based on the TEM and SAED analysis, it is found that all the prepared Ni nanowires were polycrystalline, and these polycrystalline Ni nanowires possess a FCC structure. On the other hand, the as-synthesized Ni nanowires were found to be very sensitive to the magnetic field. In this study, we experimentally demonstrated that by applying external magnetic fields, these Ni nanowires can be controlled to align along the directions of applied magnetic fields and assemble into a 2-D ordered pattern on Si substrate.
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Wu, You-Han, and 巫宥翰. "Photocatalytic properties of Ni-silicide/Si heterostructure nanowire arrays." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/93655457084829207475.
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Wang, Wen-Hung, and 王文鴻. "Ni-DNA based Y shape nanowire device development and characterization." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/97zeb8.
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Wang, Hui-Tung, and 王惠東. "Study on ZnO-nanowire interdigitated electrodes for electroplating Ni-Co solution." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/42663800919078853643.
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碩士中原大學
機械工程研究所
104
Abstract A simple and inexpensive approach to selectively synthesized the ZnO nanowires at the specific area is proposed in this study. By integrating the hydrothermal method with the photolithography process, both the positive and negative resists were used to control the growth of nanowires through lift-off concept. The printed circuit board (PCB) was adopted as the substrate. On PCB, the interdigitated electrodes (IDE) array was firstly fabricated by etching the copper foil. Two types of chips were compared: global growth of ZnO nanowires on the device and patterned ZnO nanowires between IDE. Based on the Faraday''s law of induction, it is found that the ZnO nanowires have Faraday''s law of induction to capture electroplating solution of Metal. The detection of immobilized proteins is related to the variation of the current–voltage (I–V) characteristic curve. The experimental results show that ZnO nanowires have reliable immobilization capability for a wide range of electroplating solution concentrations. In addition, the electroplating solution from（0.16 g/L to 55 ng/L）can be detected. The chip with patterned ZnO nanowires between IDE is more sensitive than that with global growth of ZnO nanowires, even for small volume of electroplating solution.
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Chen, Sing-Da, and 陳星達. "Fabrication of Ni/Au multilayered nanowire arrays in anodic aluminum oxide." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/49778427343472886719.
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Huang, Ching-neng, and 黃勤能. "Electrochemical synthesis of Ni-Co nanowire arrays in anodic alumina oxide template." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/66787603131113231496.
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碩士國立中央大學
化學工程與材料工程研究所
95
Recently, Co-Ni alloy thin film and particles have already been found their potential applications in sensors, advanced micoactuators, and magnetic recording medias. However, the synthesis and applications of one-dimensional (1-D) Co-Ni alloy nanowires with different contents have not been intensively studied. To fabricate large-area size-tunable Co-Ni alloy nanowire array at low-cost, an effective and economical technique-anodic alumina oxide (AAO) template-assisted electrodeposition process is one of the most promising schemes to replace the conventional lithography methods. In the study, we demonstrated that the AAO template with 2-D periodic nanopore structure and large-scale well-aligned Co-Ni alloy nanowire array with different composition ratio of Co and Ni were successfully fabricated under controlled synthesizing conditions. The pore diameter and lengths of the as-prepared AAO template can be tuned from 20-100 nm and 40-130 μm, respectively. After DC electrodeposition and subsequent removing the AAO templates, high-density, well-aligned Co-Ni alloy nanowires with different concentration ratio of Co to Ni(Co:Ni=1:9, Co:Ni=1:1, Co:Ni=9:1) were were successfully synthesizied. From the EDS line-scan profiles analysis, it is revealed that alloy nanowires were entirely composed of Co and Ni, and uniforem distributions of Co anf Ni throughout these nanowires. Based on the TEM and SAED analysis, it is found that the three sets of Co-Nialloy nanowires were all single crystalline, and these single crystalline Co-Ni nanowire possess a HCP structure. The growth direction of the Co-Ni alloy nanowires of samples A(Co:Ni=1:9), B(Co:Ni=1:1), and C(Co:Ni=9:1) were identified to be along the [1 11], [ 41], and [ 41] directions, repectively. On the other Hand, the Co-Ni nanowires were found to be very sensitive to the magnetic. In this study, we experimentally demonstrated that by applying external magnetic fileds, these Co-Ni nanowires can be controlled to align along the directions of applied magnetic filed and assemble into a 2-D ordered pattern on Si substrate.
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Jhou, Guan-Sing, and 周冠行. "The NO2 Adsorption and Dissociation on pure Pd and Ni@Pd Nanowire." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/46456510198463910524.
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碩士中國文化大學
化學系應用化學碩士班
100
Our calculations with spin-polarized density functional theory was carried out to characterize the adsorption and dissociation of NO2 molecule on the Pd and Ni@Pd nanowire, which are combine with 22 Pd and 6Ni@16Pd. The molecular structures and adsorbate/substrate interaction energies of NO2/Pd, NO /Pd, N/Pd ,O/Pd and NO2/Ni@Pd, NO / Ni@Pd, N/ Ni@Pd, O/ Ni@Pd configurations were predicted. It was shown that the barriers for the stepwise NO2 dissociation reaction for Pd, NO2(a), are -21.99 kcal/mol àNO(a)+O(a), are -48.08 kcal/mol (for NO-O bond activation the barriers are 15.52 kcal/mol), àN(a)+2O(a), are -30.07 kcal/mol (for N-O bond activation the barriers are 53.52 kcal/mol), for Ni@Pd, NO2(a), are -34.31 kcal/mol àNO(a)+O(a), are -78.53 kcal/mol (for NO-O bond activation the barriers are 3.98 kcal/mol), àN(a)+2O(a), are -89.08 kcal/mol (for N-O bond activation the barriers are 40.96 kcal/mol). It shows that the adsorption and dissociation of NO2 molecule of Ni@Pd nanowire is better than Pd nanowire.
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Wang, Bau-Ming, and 王寶明. "Improved Performance of NILC LTPS Thin-Film & Nanowire Transistors through Ni-Gettering." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/79264213071607548787.
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博士國立交通大學
材料科學與工程學系
98
Low temperature polycrystalline silicon (LTPS) Ni-metal induced lateral crystallization (NILC) thin-film transistors (TFTs) have been investigated in this thesis. Ni impurities trapped inside the NILC poly-Si films is an issue. Therefore the Ni-gettering method is proposed to effectively reduce Ni residues within the NILC poly-Si films. It involves using gettering layers/etching stop layers as the Ni-gettering structure. The 100-nm-thick top α-Si and phosphorous-doped α-Si layers serve as the gettering layers, while the middle ~5-nm-thick chem-SiO2 layer is used as an etching stop layer. Moreover the proposed gettering method is utilized in the fabrication of LTPS NILC TFTs and Si nanowire (NW) channel transistors to investigate the effect of Ni-metal inside poly-Si on the device performance. First, the α-Si film is employed to getter Ni-silicides within NILC poly-Si film and Ni reduction is demonstrated by SEM. After the gettering process, fewer and smaller silicide-etching holes are found at the NILC/NILC boundaries. It is found that top α-Si films, Ni-gettering layers, transfer into NILC poly-Si verified by SEM. This means that during the gettering process, Ni atoms diffused from the NILC poly-Si film through chem-SiO2 into the Ni-gettering layer due to the concentration gradient. Compared with the previous α-Si/PECVD-SiNx study, the thermal budget is greatly reduced. It’s because of low Ni diffusivity in SiNx films resulting a long annealing time as 90 h at 550oC in N2 ambient. In order to improve the Ni-gettering efficiency, phosphorous-doped α-Si films are further used by ion implantation. After a gettering process, there are almost no silicide-etching holes observed at the NILC/NILC boundaries. These results indicate that phosphorous dopants could improve the gettering efficiency of α-Si due to the solubility enhancement of Ni impurities. But the gettering efficiency do not obviously improves until doping phosphorus ions reach a dose of 1×1016 cm-2. The concentration distribution of Ni is similar to that of phosphorous atoms since the projection range of phosphorous ions is set at the middle of the α-Si film. This result also indicates that phosphorus could trap Ni atoms. The proposed gettering method is further utilized in the fabrication of LTPS NILC TFTs. As NILC TFTs are treated with a Ni-gettering process, they reveal lower leakage current, higher on/off current ratio, higher mobility, and better uniformity. These improvements are all attributed to the reduction of Ni impurities in gettered poly-Si films. Finally, a simple method and low-cost process is used to manufacture the NW channels. The feature of process is the method of forming sidewall spacer of MOSFET. The poly-Si sidewall spacer NW channels self-alignment form in the process of defining source/drain (S/D). Both the vertical width (WNW) and the horizontal sidewall thickness (TNW) of poly-Si NWs are about 70 nm. The cross-section of fabricated poly-Si NWs is similar to triangular shape by an anisotropic etching. Compared with the traditional TFTs, the side-gated NWs TFTs have higher channel controllability. Moreover, the performance of NILC NWs TFTs is improved after a Ni-gettering process. This is because of the reduction of Ni and NiSi2 precipitates randomly trapped at poly-Si/gate oxide interfaces and poly-Si grain boundaries.
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tsao, kung-cheng, and 曹公誠. "Fabrication of amorphous and magnetic Ni-W-P nanowire arrays by electroless plating." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/22991847913983814225.
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碩士南台科技大學
化學工程與材枓工程系
94
Abstract In this study, the Ni-W-P nanowire arrays prepared using the arrays nanoporous of anodic aluminum oxide membrane as a template (AAO template ) with an electroless method. The influence of pH value of electrolyte on the properties of deposited alloy nanowire during pH4.5~9.5 range with electroless have been investigated. The structure of deposited alloy nanowires are amorphous structure in varieus pH value ranges that electrolyte pH value (4.5~9.5 ) by XRD analysed. The composition of deposited alloy nanowires have only Ni and P as pH value for 6.5 under, what there is no W appearing. There is W appeared and formed Ni-W-P alloy nanowire when pH value aboves 7, and the W content will increase with the increase of electrolyte pH value. On the other hand, amount of the W composition approach a maximum value while electrolyte of pH 8.5, however, the alloy nanowire can,t be formed well. Therefore, the range of pH7~8 can be formed good nanowire. The magnetic properties of deposited alloy nanowires with the range of pH pH7~8(ie: the W content are 4~6 wt%) have been structure by VSM analysed. This result indicate that there is a highest saturated magnetization exists under the pH8 condition. Therefore pH value of electrolyte and the W content in the alloy nanowire affect significantly on the nanowire growth morphology and properties magnetism. The Ni-W-P alloy nanowire growth mechanism has been investigated. When electrolyte flow through the catalyzes surface and the alloy particles have been deposited on these surface, and the alloy particles becomes the tubular structure upward autocatalytic to pile up again forms Ni-W-P alloy nanowire structure. On the other hand, except has nanowire formation, still has nanoparticles and nanotube structure exists on the bottom of AAO. The influence of nanotubular and nanoparticles on the magnetic can be neglected. The influence of the concentration (10~20 g/L) of Na2WO4 in electrolyte has been investigated. The result indicated that the content of W in Ni-W-P alloy nanowire is increased with increasing of the concentration of Na2WO4 in electrolyte. When the Na2WO4 concentration is 15 g/L, The W content in the Ni-W-P alloy nanowire can reach to 16wt%, also may produce the growth mechanism specially, and the length of nanowire is near 15 μm. The saturation magnetization quantity for this condition to be highest near 534emu/cm3. Therefore, the Na2WO4 concentration is the very important parameter. The influence of the concentration of NiSO4(10~20 g/L) and NaH2PO2(17~27 g/L) in electrolyte on the properties of deposited alloy nanowires have been studied. From these results indicate the concentration of NiSO4 and NaH2PO2 can obviously affect the composition of Ni-W-P nanowire. The lower NiSO4 concentration and higher NaH2PO2 concentration may obtain the higher W content in the Ni-W-P alloy nanowire. Therefore, the deposited Ni-W-P alloy nanowire using the electrolyte pH value is 8, and electrolyte composition of Na2WO4 15 g/L, NaH2PO2 22 g/L and NiSO4 15 g/L can be obtained the better nanowire morphology and the best magnetic property.
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楊子明. "Fabrication and Characterization of High Performance NILC LTPS Nanowire TFTs using Ni-Gettering." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/47797240542309690009.
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碩士國立交通大學
工學院碩士在職專班半導體材料與製程設備組
97
In this thesis, fabrication and characterization of high performance NILC LTPS nanowire TFTs using Ni-gettering has been studied. Initially, we employ LTPS NILC technology to fabricate TFTs with poly-Si nanowire channels. It’s a simple method and low-cost process to manufacture the nanowire channels. The feature of process was the method of forming sidewall spacer of MOSFET. Simultaneously, we define source/drain and self-alignment form the poly-Si sidewall spacer nanowire channels for the bottom-gate TFT. Thus, we can simply control the width of sidewall spacer nanowire channel around 70 nm by etching condition. Moreover, due to NILC Poly-Si, residual Ni trapped by the grain boundaries and defects leads to introduce deep level states and results in degradation of the device performance. Therefore, in order to solve this issue, we develop a simple and effective gettering method to reduce the Ni-metal impurity contamination of the NILC poly-Si. Finally, we execute the NH3 plasma treatment to further improve the device performance. Through this way, we reveal that the NH3 plasma treatment can effectively improve the device performance, such as passivate the defects, reduce leakage current, enhance carrier mobility, increase on/off current ratio, and better subthreshold swing, etc.
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Yi-ShuHsieh and 謝宜澍. "Fabrication of Ni-Au Alloy Nanowire Glucose Sensor for Non-enzymatic Glucose Sensing." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/auy526.
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碩士國立成功大學
微電子工程研究所
107
In this research, the fabrication of Ni-Au alloy nanowire for non-enzymatic glucose sensor on p-silicon based anodic aluminum oxide (AAO) template is discussed. The Ni-Au alloy nanowire is applied on an electrochemical glucose sensor. The Ni-Au alloy nanowire was fabricated via the self-made AAO template grown on the p-type heavily doped silicon substrate. The advantages of AAO on silicon are lower cost, stronger mechanical and less production time consuming comparing to traditional AAO grown directly by using aluminum. The electrodeposition of the Ni-Au alloy nanowire was fabricated by three-electrode system and pulse signals. The best parameter of Ni-Au alloy nanowire electrodeposition is (-1.6)V、PH2.0 and duty cycle 10%. To remove the AAO template after depositing, 2M alkaline medium was used in 30℃. The Ni-Au alloy nanowires exhibit high uniform arrangement. Further, use the Ni-Au alloy nanowires for the application of glucose measurement. After a successive injection of glucose and other substantial for measurement, the Ni-Au alloy glucose sensor exhibited a linear range of 0-3mM, a sensitivity of 1893 μA/mMcm2, and a detection limit of 1μM. Simultaneously, a superior selectivity and at least 30 days stability was also observed. The characteristics show that Ni-Au alloy nanowire has an excellent performance for glucose sensing.
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Hsu, Chia Jung, and 許佳蓉. "Influence of ultrasonic irradiation on fabrication of magnetic Ni、Ni-Co、Co nanowire arrays by using aluminum oxide as templates." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/42841314553550396435.
Full textAbstract:
碩士南台科技大學
化學工程與材枓工程系
95
In this study, the Ni nanowire arrays is prepared by using the arrays nanoporous of anodic aluminum oxide membrane as a template (AAO template) with electrodeposition method. The Ni and Ni-Co nanowire arrays were deposited with various electrolytic condition. The optimum electrolytic conditions had been investigated. The diameter of AAO pores is about 250nm. Furthermore, the growing phenomenon, microcrystalline structure and magnetic properties were investigated in the presence of ultrasonic irradiation with a various irradiation power density. The deposition rates was increased with the increasing of the electrolytic potential without ultrasonic irradiation. Ni nanowires almost not be obtained as the electrolytic potential less then -0.8V. The Ni nanowires were deposited successfully in the electrolytic potential range of -0.8V to -1.0V. On the other hand, the Ni nanowires were not grown uniformly as the electrolytic potential above -1.1V. Therefore, the optimum electrolytic potential was determined of -1.0V. On the other hand, the rates of Ni nanowires deposition increased with increasing of the ultrasonic irradiation power density in the presence of ultrasonic irradiation. When the microstructure had not change significantly under 12W of ultrasonic irradiation power density compared with the absence of ultrasonic irradiation. When ultrasonic irradiation power densities were above 15W, the preferred growth orientations of Ni nanowires was (111) plane, and the (111) plane was the maximum when power density of ultrasonic irradiation was 18W. The analysis of growth rate, crystallinity and magnetic properties of Ni-Co nanowires increased with ultrasonic irradiation compared with without ultrasonic irradiation, because of the strong agitation effect was generated during ultrasonic irradiation. XRD pattern shown the Co-Ni alloy nanowire deposited that the crystal structure was fcc mixes hcp structure in the absence of ultrasonic. The (111) plane was improved with the ultrasonic irradiation and the Ni content of Ni-Co nanowires deposited. Furthermore, the crystallinity of the Ni-Co nanowires deposited increased with two effects. On the other hand, in the presence of ultrasonic irradiation the referred growth orientations of fcc (111) plane was inhibited and improved the hcp (100) growth, because the shock wave effects generated during ultrasonic irradiation. The magnetic properties of Ni-Co alloy nanowire arrays were determined by VSM with a function of Ni-Co composition, even use ultrasonic or not. The magnetic easy axis of the Ni-Co alloy nanowire was perpendicular the nanowire, and with ultrasonic irradiation(18W) that the crystallinity was better then without ultrasonic irradiation. Because the shock wave effect of ultrasonic irradiation improved the (111) perfect orientation plane, and make magnetic properties became more better. The magneticcrystalline aniosotrppy affected on the alloy Ni-Co nanowire deposited become hard magnetic, and in the same time we can find the pure Ni and pure Co are all soft magnetic, It was indicated that you can discretionarily fabricated different content magnetic nanowire all you need .
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Sutrakar, Vijay Kumar. "A Computational Study of Structural and Thermo-Mechanical Behavior of Metallic Nanowires." Thesis, 2013. http://etd.iisc.ernet.in/2005/3370.
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This thesis is an attempt to understand ways to improve thermo-mechanical and structural properties of nano-structured materials. A detailed study on computational design and analysis of metallic nanowires is carried out. Molecular dynamic simulation method is applied. In particular, FCC metallic nanowires, NiAl, and CuZr nanowires are studied. Various bottom-up approaches are suggested with improved structural and thermo¬mechanical properties.
In the first part of the thesis, Cu nanowires are considered. Existence of a novel and stable pentagonal multi-shell nanobridge structure of Cu under high strain rate tensile loading is reported. Such a structure shows enhanced mechanical properties. A three-fold pseudo-elastic-plastic shape recovery mechanism in such nanowires is established. This study also shows that the length of the pentagonal nanobridge structures can be characterized by its inelastic strain. It is also reported that an initial FCC structure is transformed into a new HCP structure. The evidence of HCP structure is confirmed with the help of experimental data published in the literature. Subsequent to the above study, a novel mechanism involving coupled temperature-stress dependent reorientation in FCC nanowires is investigated. A detailed map is generated for size dependent stress-temperature induced solid-solid reorientation in Cu nanowires.
In the second part of the thesis, deformation mechanisms in NiAl based intermetallic nanowires are studied. A novel mechanism of temperature and cross-section dependent pseudo-elastic/pseudo-plastic shape and strain recovery by an initial B2 phase of NiAl nanowire is reported. Such a recoverable strain, which is as high as ~ 30%, can potentially be utilized to realize various types of shape memory and strain sensing phenomena in nano-scale devices. An asymmetry in tensile and compressive yield strength behavior is also observed, which is due to the softening and hardening of the nanowires under tensile and compressive loadings, respectively. Two different deformation mechanisms dominated by twinning under tension and slip under compression are found. Most interestingly, a superplastic behavior with a failure strain of up to 700% in the intermetallic NiAl nanowires is found to exist at a temperature of 0.36Tm. Such superplastic behavior is attributed to the transformation of the nanowire from a crystalline phase to an amorphous phase after yielding of the nanowire.
In the last part the work, another type of nanowires having Cu-Zr system is considered. A novel stress induced martensitic phase transformation from an initial B2 phase to BCT phase in a CuZr nanowire under tensile loading is reported. It is further shown that such a stress induced martenistic phase transformation can be achieved under both tensile as well as compressive loadings. Tensile-compressive asymmetry in the stress-strain behavior is observed due to two different phase transformation mechanisms having maximum transformation strains of ~ 5% under compressive loading and ~ 20% under tensile loading. A size and temperature dependent tensile phase transformation in the nanowire is also observed. Small nanowires show a single step tensile phase transformation whereas the nanowires with larger size show a two step deformation mechanism via an intermediate R-phase hardening followed by R-phase yielding. A study of energetic behavior of these nanowires reveals uniform distribution of stress over the nanowire cross-section and such stress distribution can lead to a significant improvement in its thermo-mechanical properties. Similar improvement is demonstrated by designing the nanowires via manipulating the surface configuration of B2-CuZr system. It is found that the CuZr nanowires with Zr atoms at the surface sites are energetically more stable and also give a uniform distribution of stresses across the cross-section. This leads to the improvement in yield strength as well as failure strain. An approach to design energetically stable nano-structured materials via manipulating the surface configurations with improved thermo-mechanical properties is demonstrated which can help in fundamental understanding and development of similar structures with more stability and enhanced structural properties. Further ab-initio and experimental studies on the confirmation of the stability of the nanowires via manipulating the surface site is an open area of research and related future scopes are highlighted in the closure.
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Huang, Ting-Kai, and 黃亭愷. "Resistive Switching Properties and Behaviors in Core-Shell Ni/NiO/HfO2 Nanowire ReRAM Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/qmf35z.
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碩士國立交通大學
材料科學與工程學系所
105
Resistive Random Access Memory (RRAM) is one of the most promising nonvolatile memory because it has several advantages; for example, simple MIM (metal-insulator-metal) structure, fast operation speed, high endurance, high retention, and low energy consumption. However, the reliability is not persistent and completely switching mechanism is not fully understood. In this work, we deposited different metal oxide (HfO2, Al2O3) covering the Ni/NiO nanowire by atomic-layer-deposition (ALD). The different properties, including electrical characteristics, surface morphology, and elements distribution have been systematically investigated. The electrical characteristics were excellent, and the endurance could up to 200 cycles, which is pretty good for 1-D nanostructure. Also, we used focus-ion-beam (FIB) to prepare TEM sample subsequently following TEM observation. From the TEM analysis, we made sure the position of conducting filament (CF) and confirmed the element components of CF. The diffusion of oxygen vacancies formed the conducting filament, resulting in the change of morphology. The study enriched the understanding of the mechanism and provided a new design to enhance switching properties of RRAM.
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Chen, Kuan-yu, and 陳冠宇. "Fabrication of nickel metal nanowire arrays by using AAO templates technique and the interfacial reactions of the Ni nanowires on (001)Si substrates." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/05410010796549465346.
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碩士國立中央大學
化學工程與材料工程研究所
95
In this study, the fabrications of large-area well-aligned nickel metal nanowire arrays by using the electrodeposition in conjunction with removable anodic aluminum oxide (AAO) templates technique, and the interfacial reactions of the Ni nanowires on (001)Si substrates after different heat treatments have been investigated. Under controlled anodization conditions, self-ordered nanochannel structures were produced by anodization of high-purity aluminum sheets in appropriate acid solutions. The pore sizes of AAO templates can be tuned from 20 to 100 nm by varying the component of electrolyte, the processing temperature, and the applied anodic voltage. After electrodeposition of Ni into the nanochannels and subsequent removing the AAO templates, a large amount of Ni metal nanowires of same diameter were obtained. Based on TEM and selected-area electron diffraction (SAED) analysis, some of the prepared Ni nanowires were single crystalline and the growth directions of these Ni nanowires were found to be affected by the pore sizes of AAO templates. The dominate growth directions of the Ni nanowires produced from 250 nm and 50 nm pore sizes AAO templates were along the <111> and <110> crystal directions, respectively. For the 50 nm Ni nanowires on (001)Si substrates after annealing at 400 ℃, epitaxial NiSi2 phase was found to coexist with the ploycrystalline NiSi phase. The nucleation temperature of NiSi2 phase in the nanoscale Ni wires/(001)Si samples was found to be lowered by about 350 ℃ compared to what is usually needed for the growth of NiSi2 (~750 ℃). The results revealed that the growth of epitaxial NiSi2 was more favorable for the miniature size Ni metal wires. For the samples annealed at 500 ℃ or above, morphological degradation of Ni silicide nanowires were evident. These epitaxial NiSi2 nanowires formed on (001)Si were found to be heavily faceted and the faceted structures were more prone to form at higher temperatures. The faceted structure of epitaxial NiSi2 was identified to be an inverse pyramid in shape, and each pyramidal-shaped NiSi2 dot was composed of one (001) surface and four {111} interfaces. Furthermore, from the analysis of the SAED patterns, the epitaxial orientation relationship between the NiSi2 and silicon substrates was identified to be [001] NiSi2 // [001] Si and (200) NiSi2 // (400) Si.
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Hsu, Chao Wei, and 徐肇蔚. "Synthesis and characterization of Cu-Ni core-shell nanowires." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/u22gj5.
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碩士國立清華大學
材料科學工程學系
103
Due to it’ s good conductivity and low-cost property, copper (Cu) is often used as interconnect and flexible transparent conductive film material with the introduction of nano-processing. Therefore, many studies try to analyze the properties of copper in nanoscale, such as nanowires (NWs). Twin is a common microstructure in metals. It has been demonstrated that nano-twinned copper have high mechanical strength, good conductivity, and moreover, superior electromigration resistance. In our previous study, we have successfully fabricated Cu NWs with high density of nanoscale traverse twinning structure by using pulsed electrodeposition at low temperature. The formation of nano-twinned structure can also improve the corrosion properties of Cu metallization by changing grain boundary structure. However, research report on the oxidation characteristics of nanotwinned Cu NWs is limited. Copper is prone to oxidation in nanoscale because of high surface-to-volume ratio, some researches showed that Cu-Ni NWs with core-shell structure that was prepared by coating a thin Ni layer on Cu NWs using chemical reduction method possesses good oxidation resistance. Nevertheless, these treatment were mostly done by using highly toxic reducing agent. In this study, high aspect-ratio nano-twinned Cu NWs were prepared by pulsed current (PC) electroplating, and Cu-Ni core-shell NWs were successfully prepared by the low-toxicity reducing agent, sodium borohydride. Time-and-temperature dependence of electrical resistivity for single Cu and Cu-Ni NWs prepared by micro-fabrication process has been investigated. The bamboo-like twinning structure and core-shell structure of Cu-Ni NWs have been examined by transmission electron microscopy (TEM) and UV-visible/TEM Energy Disperse X-ray analysis. According to four-probe I-V electrical measurement, the resistivity of Cu NWs with nanotwins remained almost constant after exposed in ambient air for one month, while the resistivity of Cu-Ni core-shell NWs also kept unchanged after hundreds hours of thermal aging, revealing good chemical stability.
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侯蘊芳. "Thermal conductivity of Ni nanowires affected by magnetic field." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88675659709656617998.
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Huang, Wan-Ru, and 黃琬茹. "Fabrication of Ni-silicide / Si heterostructure nanowires by nanosphere lithography." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/79656754305490325260.
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碩士國立中興大學
材料科學與工程學系所
99
With the shrinking of the dimensions of electronic devices, the-low resistivity and high-stability metal silicides have been widely used as the contacts on source, drain, gate in transistors to reduce contact resistance. Preferred silicides for the applications are titanium silicide (TiSi2), cobalt silicide (CoSi2) and nickel silicide (NiSi). Because NiSi has a wide process window, less silicon consumption, low film stress, nickel silicide is consider to be the most promising candidate for scaled devices below one hundred nanometers. In the study of nanoelectronic devices, carbon nanotubes (CNT) and silicon nanowires (SiNW) have been used as building blocks. However, the structure and size of CNTs is difficult to control process. The size of SiNWs can be controlled by a lithography technology, and can be integrated with semiconductor process. Therefore, SiNW has advantage over CNT. As the semiconductor industry continues to shrink the dimensions of electronic devices, the study of properties of metal silicide nanowires becoming more and more importance. In this study, a large number of nanowires with a controlled diameter, growth orientation were fabricated by combining polystyrene nanosphere lithography with metal-induced catalyst etching. Then, nickel silicide/ silicon heterostructure nanowires were formed by glancing angle deposition technique and solid-phase reaction. The effects of the size of Si nanowires on the formation of nickel silicide and the electrical property of nickel silicide/silicon interfaces in heterostructure nanowires were investigated. The results show that nickel silicide/silicon heterostructure nanowires were fabricated successfully. The front-end of nickel silicide part is Ni3Si2, The silicides formed at the silicide/silicon interface were NiSi and NiSi2 in the thinner nanowires (diameter≦105nm) and the thicker nanowires (diameter≧110nm), respectively, which is because that the formation of nickel silicide was a surface diffusion controlled process. The interfacial electrical properties of NiSi/silicon hetrojunction (in the thinner nanowires) and NiSi2/silicon hetrojunction (in the thicker nanowires) were Schottky contact and Ohmic contact, respectively.
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Hong, Jyu-Chao, and 洪鉅晁. "Ni-Mn hydroxide/ZnO nanowires/Carbon fiber for supercapacitor applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/29a89t.
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碩士國立清華大學
材料科學工程學系
106
ZnO nanowires (NWs) have been considered as a promising supporting material for hybrid supercapacitors due to its excellent mechanical property, good electronic conductivity and easy-fabrication. In this study, a high-performance supercapacitor based on Ni-Mn hydroxide modified ZnO NWs on carbon fiber (CF) was developed. The well-aligned ZnO NWs were synthesized on carbon fiber by chemical bath deposition, followed by pulse pulse electrodeposition of Ni-Mn hydroxide on the surface of ZnO NWs. The effects of the electrodeposition conditions as well as the Ni/Mn bath ratio were systematically investigated. The Ni-Mn hydroxide/ZnO NWs/CF composite electrode fabricated under the optimal deposition conditions has exhibited a large specific capacitance of 1039 F/g at 5 mV/s, but only ~68% retention after 3000 cycles. However, upon annealing at 200 ºC for 2 h, the retention of the electrode was largely enhanced up to 86%, probably due to the formation of Ni-Mn oxide.
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Wang, Jiun-Yu, and 王俊喻. "Size effect on Field Emission properties of Si nanowires arrays and electronic properties of Ni-Silicide/Si heterostructure nanowires." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/44674757409904380085.
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碩士國立中興大學
材料科學與工程學系所
100
Nanoscale Schottky contact used for diodes, Schottky barrier field effect transistors and solar cells have been extensively studied. The Schottky metal silicide/Si heterojunctions in nanostructures have been widely investigated due to their applicability to Si-based devices. The free-standing Si NW arrays have been fabricated by the combining nanosphere lithography with metal-assisted catalytic etching. Further, chemical etching using a KOH solution was performed for adjusting the diameter of nanowires. Then, nickel silicide/Si heterostructure nanowires were formed by reactive deposition epitaxy and a glancing angle deposition technique. The results show that with reducing the diameter of Si nanowires, the turn-on field decreased and field emission enhancement factor increased. This phenomenon indicated that increasing the aspect ratio of nanowires can improve their field emission properties. Ni-silicides were formed at the apex of Si nanowires after depositing Ni at 400°C by the glancing angle deposition technique. The phase of silicide at the silicide/Si interface was NiSi2. When the diameter of nanowires reduced to 70 nm the front end of silicide was Ni2Si. The NiSi2/silicon heterojunction was Schottky contact. The Schottky barrier height was in the range of 0.39 to 0.45 eV, and the ideal factor was in the range of 3.1 to 3.5.
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Guo, Zhen-hao, and 郭鎮豪. "Fabrication and Properties of Anodic Aluminum Oxide Templates and Co-Ni Alloy Nanowires." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/59521231830061221783.
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碩士國立中央大學
化學工程與材料工程研究所
97
In this study, the AAO template with large-area nanopores structure and the large-scale well-aligned pure Ni, Co, and Co-Ni alloy nanowires arrays with different composition ratio of Co and Ni were successfully fabricated under controlled processing conditions. The average pore size of the AAO template produced was about 25 nm. On the other hand, pure Ni, Co, and Co-Ni alloy nanowires with different concentration ratios of Co to Ni (Co:Ni=1:9, Co:Ni=1:1, Co:Ni=9:1) were successfully synthesized by DC electrodeposition into nanopores of commercial AAO template. Based on the TEM and SAED analyses, it is found that the Ni and Co nanowires were polycrystalline with FCC and HCP structures, respectively. In addition, the three sets of Co-Ni alloy nanowires were all single crystalline, and these single crystalline Co-Ni nanowire possess a HCP structure. The average diameter of the metal and alloy nanowires was about 250 nm. From the EDS line-scan profiles analysis, it is revealed that alloy nanowires were entirely composed of Co and Ni, and uniform distributions of Co and Ni throughout these nanowires. The growth direction of the Co-Ni alloy nanowires of samples A (Co:Ni=1:9), B (Co:Ni=1:1), and C (Co:Ni=9:1) were identified to be along the[-6241], [-3211], and [02-21] directions, respectively. From electrical property measurement, the addition of Co to Ni could strongly affect the resistivity of Co-Ni alloy nanowires. The resistivity of Co-Ni nanowire was found to increase with the addition of Co to Ni first then decrease. The results are discussed in the context of the Nordheim’s rule. On the other hand, the Co-Ni nanowires were found to be very sensitive to the externally applied magnetic field. In this study, experimental result demonstrated that by applying external magnetic fields, these Co-Ni nanowires can be controlled to align along the directions of applied magnetic filed and assemble into a 2D ordered pattern on Si substrate.
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Liou, Jyun Fu, and 劉俊甫. "Solution-based synthesis of Ag-Ni Core-shell nanowires and study of their property." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/60348222894501490225.
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Chien, Wen-Ching, and 簡文慶. "Fabrication of Ni-silicide / Si Heterostructure Nanowires-based Photosensing Devices by Electric Field Assembly Method." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/67957857581350933894.
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碩士國立中興大學
材料科學與工程學系所
105
Transition metal silicides have been widely used as ohmic contacts, Schottky barrier contacts, gate electrodes and interconnects in silicon microelectronic devices because of their low resistivity and thermal stability. NiSi_2 has a small lattice mismatch of -0.4 % with Si makes it an attractive material for use in the formation of epitaxial silicide. Thus, the applications of it in the diodes, field effect transistors, solar cells and photosensing devices are widely discussed. In this study, silicon nanowire arrays were fabricated by metal- assisted chemical etching combined with nanosphere lithography. NiSi_2/Si heterostructured nanowire arrays were fabricated by glancing angle Ni deposition and reactive deposition epitaxy (RDE) at 500 ℃, and subsequently used as building blocks for NiSi_2/Si heterostructured nanowire-based devices using alternating current (AC), direct current (DC) and DC-offset AC dielectrophoresis alignment.The electrical and photosensing properties of the devices were investigated. The results show that the rectifying devices were achieved by electric field assembly of NiSi_2/Si heterostructured nanowires with DC and DC-offset AC field applications and the linear ones were formed by AC field applications. For white light photosensing, the rectifying devices have higher sensitivity in the reversed bias application comparing with linear devices. The rectifying devices can be used in infrared sensing.
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Wang, Chuan Ying, and 汪傳穎. "Synthesis and characterization of Cu-Ni core-shell nanowires for flexible transparent conducting film applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/586saq.
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碩士國立清華大學
材料科學工程學系
104
The increasing demand for flexible electronic devices drives the need for alternative materials other than indium tin oxide (ITO) as transparent conducting films (TCFs). Dispersing metallic nanowires on a polymer substrate appears to be a good solution for flexible TCFs. Among various metallic nanowires (NWs) used in TCFs, Cu based NW has been considered a potential candidate because of its cost advantage and good electrical properties. In our previous study we introduced dense nanoscale twinning structure in Cu NWs that was deposited in porous anodic aluminum oxide (AAO) templates using pulsed electroplating process. However, oxidation is the detrimental problem for the application of Cu NWs in TCFs. In this study, we have successfully synthesized Cu-Ni core-shell NWs. First, the nanotwinned Cu NWs were released from AAO templates by a wet chemical method. They were coated a thin layer of Ni using a reducing agent, sodium borohydride, in ethylene glycol solvent. We optimized the reaction temperature to achieve a smooth Ni layer coating. Next, the Cu-Ni NWs were transferred onto a PET substrate to form a TCF through vacuum filtration method and pressing process. The TCF sheet resistance is substantially reduced from 31 K/sq. to 40 /sq. at a transmittance of 88% with the optimized pressure applied during the film transfer process. The TFC sheet resistance increases 3~10 /sq. after a 1000 cycles of dynamic bending and static bending tests. Finally, the Cu-Ni TCFs had a negligible increase in sheet resistance after heating at 85 C for several hundreds of hours. It achieves the goal of improving oxidation resistance of Cu NWs by forming a Cu-Ni core-shell structure.
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Siao, Siang-Wun, and 蕭翔文. "Synthesis of Single Crystal Ni/NiO Core-Shell Nanowires and its Application at Resistive Switching Memory." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/99359615737559909115.
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碩士國立清華大學
材料科學工程學系
101
Because RRAM has many advantages such as low cost, low power, fast programming speed (twr < 100 ns), simple structure, shrinkage of cell size and nondestructive operation, it has attracted much attention for many researchers. Besides, in order to decrease the cell area and raise the density, nanowires were used to replace the thin film materials. In the literature, they usually synthesize the Ni nanowires and then oxidize the nanowires to form Ni/NiO core-shell structures. In our research, we report the growth and structural characterization of the core-shell Ni/NiO nanowires in one step. In addition, the electrical and resistance switching properties were also investigated. The Ni/NiO core-shell nanowires were synthesized by NiCl2 sources on Si substrates at 800 ℃ in source region (I) and 700 ℃ in substrate region (II) under Ar carrier gas in two-region furnace via oxide-assisted growth (OAG) mechanism. Due to the OAG mechanism, the SiO2 layer was formed outside of Ni/NiO core-shell nanowires. Then, we used HF vapor to etch away the SiO2. By different reaction temperature and flow gas, we can control the diameters and length of the nanowires. The crystal structure, morphology and chemical composition were analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM). Besides, due to fabrication of nanodevice, we use the optical microscope (OM) and a series of standard electron beam lithography (EBL). Finally, we used the Keithley 4200 to measure the I-V curve and resistive switching behaviors of core-shell Ni/NiO nanowires. Also, we designed different electrode distances of nanodevices to investigate the possible conduction path. First, different resistive switching modes such as unipolar or bipolar switching mode were observed in different electrodes, nickel and titanium. Secondly, the endurance of the Ni/NiO core-shell nanowires can be modified and the cycle number can be over 100. Finally, because the resistive switching current could be operated at micro amp (A) and lower power, the Ni/NiO core-shell nanowires have potential to become energy efficient random access memory (ReRAM).
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Zih-YingYou and 游子瑩. "Synthesis of Ni-Co Alloy Nanowires using Poly (vinyl pyrrolidone-co-acrylic acid) as a Protecting Agent." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/22857733295768104526.
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Hsu, Hsin-Jan, and 徐新然. "Spin-polarized scanning tunneling microscopy of the self-organized Ni silicide nanowires on Si (110)-16×2 surface." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/95330888366543183535.
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Lee, Yu-Chaun, and 李育全. "Direct Observation of Solid State Reaction of Si1-xGex Nanowires with Ni and Modulation of the Diffusion Mechanisms via Oxide Layer Managements." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/59eqpk.
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Petersen, Jan. "Strukturbildung und Rauigkeiten an Grenzflächen des Ni-Ag-Legierungssystems." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-0006-B469-B.
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