Nanodesign, Technology, and Computer Simulations最新文献_第2页

Magnetic properties of CNT arrays synthesized by the injection CVD method at various catalyst concentrations 不同催化剂浓度下注入CVD法合成的碳纳米管阵列的磁性能

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836974

A. Prudnikava, V. Labunov, B. Shulitski, K. Yanushkevich, A. Danilyuk, O. Demidenko

{"title":"Magnetic properties of CNT arrays synthesized by the injection CVD method at various catalyst concentrations","authors":"A. Prudnikava, V. Labunov, B. Shulitski, K. Yanushkevich, A. Danilyuk, O. Demidenko","doi":"10.1117/12.836974","DOIUrl":"https://doi.org/10.1117/12.836974","url":null,"abstract":"The arrays of multi-wall carbon nanotubes (CNTs) filled with ferromagnetic nanoparticles (MFCNTs) have been obtained by the high temperature pyrolysis of fluid hydrocarbon (o-xylene) in a mixture with the volatile source of catalyst (ferrocene) using Ar as the gas-carrier. The influence of the catalyst concentration cx (0.5%, 5%, and 10%) in the feeding solution on the composition, crystalline structure, morphology and, accordingly, magnetic properties of MFCNT arrays in a wide temperature range was investigated. The X-ray diffraction, SEM and TEM methods revealed that CNT arrays are filled by Fe3C and Fe phases and that the higher is the catalyst concentration in the feeding solution, the higher is Fe3C and Fe content in CNT arrays. Temperature dependence of the specific magnetization σ(T) shows that σ increases with the increasing of ferrocene concentration in a whole temperature range under investigation (78 ≤T < 600 K). It is shown that σ(T) follows the Bloch law in the temperature range 80-300 K with Bloch constant B=1.65.10-5 K-3/2 and the Stoner law at 300-480 K for samples with cx=10% and, correspondingly, 80-450 K with Bloch constant B=6.1.10-5 K-3/2 and 450-480 K for samples with cx=5%. The lower value of Bloch constant, which characterizes the exchange interaction, in the case of cx=10% might be attributed both to dimensional effects and the decrease of the effective magnetic momentum of Fe phases atoms. The hysteresis loops demonstrate that coercivity Hc(cx=5%) decreases, but Hc(cx=10%) is constant or even slightly increases with increasing the temperature. This phenomenon is explained by the increase both the saturation magnetization and shape anisotropy.","PeriodicalId":117315,"journal":{"name":"Nanodesign, Technology, and Computer Simulations","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114549005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Spin-dependent transport of electrons through ferromagnetic/insulator/semiconductor nanostructures 电子通过铁磁/绝缘体/半导体纳米结构的自旋相关输运

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836170

T. Sidorova, A. Danilyuk, V. E. Borisenko, F. d'Avitaya, J. Lazzari

引用次数: 2

New approach to the manufacturing of power microwave bipolar transistors at an irradiation of ohmic contacts: a computer simulation 在欧姆触点辐照下制造功率微波双极晶体管的新方法:计算机模拟

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.837085

Yu. P. Snitovsky, V. A. Efremov

引用次数: 0

Modelling of planar linear motor for microelectronic equipment 微电子设备平面直线电机建模

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.837088

V. V. Jarski

引用次数: 0

Modeling the kinetics of non-isothermal heterogeneous interaction during combustion synthesis of advanced micro- and nanocrystalline materials 模拟先进微纳米晶材料燃烧合成过程中非等温非均相相互作用动力学

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836971

B. Khina

{"title":"Modeling the kinetics of non-isothermal heterogeneous interaction during combustion synthesis of advanced micro- and nanocrystalline materials","authors":"B. Khina","doi":"10.1117/12.836971","DOIUrl":"https://doi.org/10.1117/12.836971","url":null,"abstract":"The combustion synthesis (CS), or self-propagating high-temperature synthesis (SHS) is a cost and energy efficient route for producing a wide range of refractory compounds (carbides, silicides, intermetallics) and advanced micro- and nanocrystalline materials. However, despite 40 years of extensive studies and industrial applications, intricate phase formation mechanisms that operate during CS are still not well understood. This hinders the development of novel materials and SHS-based technologies. An answer to the most urgent question in this area, viz. \"why in CS the interaction accomplishes in a short time, ~0.1-1 s, while the traditional furnace synthesis of the same material takes several hours for the same starting composition, particle size and final temperature,\" can be found only through mathematical modeling. In this work, the results of mathematical modeling of the interaction kinetics in condensed systems in non-isothermal conditions typical of CS are reported. Calculations were performed using the experimental data on SHS and diffusion parameters for the product phases on the example of TiC and NiAl. The maps of phase formation mechanisms that operate during CS are constructed. The uncommon, non-equilibrium interaction pathways, which were observed experimentally and debated in literature, are confirmed theoretically ex contrario.","PeriodicalId":117315,"journal":{"name":"Nanodesign, Technology, and Computer Simulations","volume":"7377 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131262439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Resonant properties of ordered carbon nanotube arrays 有序碳纳米管阵列的谐振特性

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836896

V. Barkaline, Pavel A. Zhuchak

引用次数: 0

Combined atomic force microscopy and optical microscopy measurements as a method of erythrocyte investigation 原子力显微镜与光学显微镜相结合的红细胞检测方法

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836481

E. Drozd, S. Chizhik

引用次数: 7

Simulation of tunneling sensor MIM-nanostructures 隧道传感器mimi -纳米结构的仿真

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.837060

V. Koleshko, A. Gulay, V. Gulay

{"title":"Simulation of tunneling sensor MIM-nanostructures","authors":"V. Koleshko, A. Gulay, V. Gulay","doi":"10.1117/12.837060","DOIUrl":"https://doi.org/10.1117/12.837060","url":null,"abstract":"The vacuum deposition process of super thin films of rare earth elements (REE) oxides was investigated and simulation of MIM nanostructures on their base was carried out. Super thin films was deposited by reactive magnetron sputtering of metallic targets in the argon and oxygen mixture. At the optimum technological regime (discharge voltage 400-440 V, substrate temperature 573-598 K) the yttrium and holmium oxides films growth rate is correspondingly 3.5 and 2.8 nm/min, their specific resistance is more than 1013 Ohm/cm, the value of permittivity is 10.4-16.8. The sensor MIM nanostructures of Al-(REE)2O3-Al type on the basis of super thin films was obtained. The resistance simulation approach by linear approximation of current-voltage relation was considered. For the yttrium oxide film thickness of 5, 16 nm and MIM-contact area of 1•10-3, 2•10-3 mm2 increasing of the applied voltage from 0.04 to 1.2-1.5 V leads to increasing of current-voltage relation steepness from (1.5-2.5)•10-8 to (19-22)•10-8 A/V, and the resistance of the formed MIM nanostructures is firstly rising and then reducing in 1.9-4.0 times with the voltage increasing. MIM nanostructures was simulated as a negative differential conductivity elements. The current through MIM nanostructures has viewed as periodic impulses with frequency from ~100 GHz to ~10 THz.","PeriodicalId":117315,"journal":{"name":"Nanodesign, Technology, and Computer Simulations","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132783363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Influence of the dispersion on boundary conditions for gas mechanics 色散对气体力学边界条件的影响

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.836987

E. Prozorova

引用次数: 0

Mathematical modeling of non-Fickian mass transport in fractured porous media 裂隙多孔介质中非菲克式质量输运的数学建模

Nanodesign, Technology, and Computer Simulations Pub Date : 2008-07-11 DOI: 10.1117/12.837011

S. Fomin, V. Chugunov, T. Hashida

{"title":"Mathematical modeling of non-Fickian mass transport in fractured porous media","authors":"S. Fomin, V. Chugunov, T. Hashida","doi":"10.1117/12.837011","DOIUrl":"https://doi.org/10.1117/12.837011","url":null,"abstract":"The paper provides an introduction to fundamental concepts of mathematical modeling of mass transport in fractured porous heterogeneous rocks. Keeping aside many important factors that can affect mass transport in subsurface, our main concern is the multi-scale character of the rock formation, which is constituted by porous domains dissected by the network of fractures. Taking into account the well documented fact that porous rocks can be considered as a fractal medium and assuming that sizes of pores vary significantly (i.e. have different characteristic scales), the fractional order differential equations that model the anomalous diffusive mass transport in such type of domains are derived and justified analytically. Analytical solutions of some particular problems of sub-diffusion and super-diffusion in the fractal media of various geometries are obtained by the method of Laplace transformations. Extending this approach to more complex situation when diffusion is accompanied by advection, solute transport in a fractured porous medium is modeled by the advection-dispersion equation with fractional time derivative. In the case of confined fractured porous aquifer, accounting for anomalous non-Fickian diffusion in the surrounding rock mass, the adopted approach leads to introduction of an additional fractional time derivative in the equation for solute transport. The closed-form solutions for concentrations in the aquifer and surrounding rocks are obtained for the arbitrary time-dependent source of contamination located in the inlet of the aquifer. Based on these solutions, different regimes of contamination of the aquifers with different physical properties can be readily modeled and analyzed.","PeriodicalId":117315,"journal":{"name":"Nanodesign, Technology, and Computer Simulations","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129198807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1