Fabrication of Graphene/Cu Composite by Chemical Vapor Deposition and Effects of Graphene Layers on Resultant Electrical Conductivity

Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil.

In situ TiB2/Cu composites fabricated by spray deposition using solid-liquid and liquid-liquid reactions

In situ TiB2/Cu composites were fabricated by both solid-liquid(S-L)and liquid-liquid(L-L)reactive spray deposition in combination with cold rolling and annealing.The microstructure and properties of the fabricated TiB2/Cu composites were investigated.The results show that the reactive mode and rolling treatment are the main factors affecting the microstructure and properties of the TiB2/Cu composite.The in situ reaction in the L-L reaction can be carried out more completely.By controlling the rolling and annealing process,the relative density and the properties of the as-deposited composites are optimized.The comprehensive performance of the deformed TiB2/Cu composite prepared by L-L reactive spray deposition(401 MPa and 83.5%IACS)is better than that by S-L reactive spray deposition(520 MPa and 20.2%IACS).

Electrical Conductivity of Collapsed Multilayer Graphene Tubes

Synthesis of multilayer graphene on copper wires by a chemical vapor deposition method is reported. After copper etching, the multilayer tube collapses forming stripes of graphitic films, their electrical conductance as a function of temperature indicate a semiconductor-like behavior. Using the multilayer graphene stripes, a cross junction is built and owing to its electrical behavior we propose that a tunneling process exists in the device.

Multiphonon hopping conduction in carbon-nickel composite films at different deposition time

In this work, the electrical properties of car- bon-nickel composite films deposited at different time （50-600 s） were investigated. The films were grown by radio frequency magnetron sputtering on glass substrates at room temperature. The electrical conductivity of the films was investigated in the temperature range of 15-500 K. The conductivity data in the temperature range of 400-500 K show the extended state conduction mecha- nism, while the multiphonon hopping （MPH） conduction is found to dominate the electrical transport in the tempera- ture range of 150-300 K. The films deposited at 180 s have the maximum conductivity. The conductivity at T 〈 60 K could be described in terms of variable range hopping （VRH） conduction. The localized state density around Fermi level （N（EF）） at low temperature for the films deposited at 180 s has the minimum value of about 4.02 × 10^21 cm^-3.eV^-1. The average hopping distance （Rhop） for the films deposited at 180 s has the maximum value of about 3.51 × 10^-7 cm.

Electrical and mechanical properties of vapour grown gallium monotelluride crystals

The physical vapour deposition （PVD） of gallium monotelluride （GaTe） in different crystalline habits was established in the growth ampoule, strongly depending on the temperature gradient. Proper control on the temperatures of source and growth zones in an indigenously fabricated dual zone furnace could yield the crystals in the form of whiskers and spherulites. Optical and electron microscopic images were examined to predict the growth mechanism of morphologies. The structural parameters of the grown spherulites were determined by X-ray powder diffraction （XRD）. The stoichiometric composition of these crystals was confirmed using energy dispersive analysis by X-rays （EDAX）. The type and nature of electrical conductivity were identified by the conventional hot probe and two probe methods, respectively. The mechanical parameters, such as Vickers microhardness, work hardening index, and yield strength, were deduced from microindentation measurements. The results show that the vapour grown p-GaTe crystals exhibit novel physical properties, which make them suitable for device applications.

Electrical Properties of Plasma Deposited Low-Dielectric-Constant Fluorinated Amorphous Carbon Films

Fluorinated amorphous carbon （a-C：F） films were deposited at room temperature using C4Fs and CH4 as precursor gases by electron cyclotron resonance chemical vapour deposition （ECR-CVD）. Chemical structures were analysed using X-ray photoelectron spectroscopy （XPS）. The current conduction shows ohmic behaviour and the leakage current increases with the content of C sp2 in the deposited a-C：F films at a low electric field. The behaviour of the leakage current is well e^plained by the Poole-Frankel mechanism at a high electric field. The interface traps, rather than chemical structures, of a-C：F films determine the PF emission current.

Optical and electrical properties of BaSnO_(3) and In_2O_(3) mixed transparent conductive films deposited by filtered cathodic vacuum arc technique at room temperature

For the crystalline temperature of BaSnO_(3)(BTO)was above 650℃,the transparent conductive BTO-based films were always deposited above this temperature on epitaxy substrates by pulsed laser deposition or molecular beam epitaxy till now which limited there application in low temperature device process.In the article,the microstructure,optical and electrical of BTO and In_(2)O_(3) mixed transparent conductive BaInSnO_(x)(BITO)film deposited by filtered cathodic vacuum arc technique(FCVA)on glass substrate at room temperature were firstly reported.The BITO film with thickness of 300 nm had mainly In_(2)O_(3) polycrystalline phase,and minor polycrystalline BTO phase with(001),(011),(111),(002),(222)crystal faces which were first deposited at room temperature on amorphous glass.The transmittance was 70%–80%in the visible light region with linear refractive index of 1.94 and extinction coefficient of 0.004 at 550-nm wavelength.The basic optical properties included the real and imaginary parts,high frequency dielectric constants,the absorption coefficient,the Urbach energy,the indirect and direct band gaps,the oscillator and dispersion energies,the static refractive index and dielectric constant,the average oscillator wavelength,oscillator length strength,the linear and the third-order nonlinear optical susceptibilities,and the nonlinear refractive index were all calculated.The film was the n-type conductor with sheet resistance of 704.7Ω/□,resistivity of 0.02Ω⋅cm,mobility of 18.9 cm2/V⋅s,and carrier electron concentration of 1.6×10^(19) cm^(−3) at room temperature.The results suggested that the BITO film deposited by FCVA had potential application in transparent conductive films-based low temperature device process.

A layered multifunctional framework based on polyacrylonitrile and MOF derivatives for stable lithium metal anode

Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition behavior still occurs at the top of 3D frameworks owing to the local accumulation of Li ions.To promote uniform Li deposition without top dendrite growth,herein,a layered multifunctional framework based on oxidation-treated polyacrylonitrile(OPAN) and metal-organic framework(MOF) derivatives was proposed for rationally regulating the distribution of Li ions flux,nucleation sites,and electrical conductivity.Profiting from these merits,the OPAN/carbon nano fiber-MOF(CMOF) composite framework demonstrated a reversible Li plating/stripping behavior for 500 cycles with a stable Coulombic efficiency of around 99.0% at the current density of 2 mA/cm~2.Besides,such a Li composite anode exhibited a superior cycle lifespan of over 1300 h under a low polarized voltage of 18 mV in symmetrical cells.When the Li composite anode was paired with LiFePO_(4)(LFP) cathode,the obtained full cell exhibited a stable cycling over 500 cycles.Moreover,the COMSOL Multiphysics simulation was conducted to reveal the effects on homogeneous Li ions distribution derived from the above-mentioned OPAN/CMOF framework and electrical insulation/conduction design.These electrochemical and simulated results shed light on the difficulties of designing stable and safe Li metal anode via optimizing the 3D frameworks.

石墨烯增强铜基复合材料的制备及性能研究

以三维泡沫铜为基体,采用化学气相沉积得到石墨烯铜复合体,同时解决了石墨烯在铜基体中分散性和界面结合问题,再用铜粉填充泡沫铜孔隙,然后真空热压制备石墨烯增强铜基复合材料。探究了石墨烯对铜基体复合材料导电性及拉伸性能的增强效果。研究发现,石墨烯对铜基体性能有明显增强作用,在50 sccm甲烷通量下15 min时沉积的石墨烯性能增强效果最佳。热压制备的石墨烯增强铜基复合材料的导电性能达到86.2%IACS,抗拉强度提高到338 MPa,屈服强度也达到214 MPa。

退火温度对BCZT外延薄膜电学性能的影响及其导电机制分析

脉冲激光沉积技术制备Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3)(BCZT)外延薄膜时通常需要较高的沉积温度,且易含有氧空位缺陷。本文旨在提供一种基于脉冲激光沉积技术接后退火处理工艺,并成功在导电基板上制备了高质量BCZT外延薄膜,探究了退火温度对BCZT外延薄膜结构和性能的影响。不同温度(750、800、850和900℃)退火后薄膜均呈现纯净物相,且随着退火温度的升高,薄膜的铁电性能逐渐提高,2Pr由4.2μC/cm^(2)提升至17.6μC/cm^(2),但900℃退火温度下薄膜样品的漏电流问题最严重。通过拟合J-E关系表明,低电场下700℃至850℃退火后的薄膜均遵循欧姆导电机制,而900℃退火后的薄膜遵循空间电荷限制电流机制,高电场下所有退火温度下的薄膜均遵循福勒-诺德海姆隧穿机制。

用电导率法研究石油中沥青质沉积问题

介绍了检测石油中沥青质沉积的电导率方法，考察了在加溶剂（正庚烷和甲苯）过程中其体系电导率的变化规律。结果表明，随着溶剂的加入，两种溶剂体系的电导率均呈先升后降的趋势。在电导率变化的一阶导数曲线上，正庚烷体系出现一最高点，该点对应于此法的沥青质沉积起始点；而一般情况下甲苯体系不出现此点。各原油的沥青质沉积起始点均明显早于其相应的减压渣油，表明渣油体系比原油体系更稳定。

东天山镜儿泉铜镍矿床成矿预测及EH4地球物理测量依据

镜儿泉铜镍矿床产于东天山黄山-镜儿泉铜镍成矿带东部，是典型的岩浆熔离型铜镍硫化物矿床。岩体地质研究表明，基性-超基性葫芦岩体是一复式岩体，东部辉石岩相形成的小环切穿西部辉石岩相形成的大环，两环相交呈葫芦状。矿床形成受岩体控制，矿体呈似层状赋存于复式岩体西部辉石岩相的底部。EH4连续电导率成像仪测量结果清晰地反映了岩体的基本形态，识别了岩体的不同岩相：①超基性岩（1～300Ωm）在南北剖面呈不对称的盆状，东西剖面呈东浅西深相交的盆状，舍矿辉石岩相（130～300nm）呈盆状分布于橄榄岩相（1～130nm）外围；②中基性岩（500～1000Ωm）包括辉长岩相和闪长岩相呈漏斗状分布于辉石岩相外围，漏斗状形态预示岩浆上升通道可能在矿区西南部，在此基础上，预测葫芦岩体地下250～450m区段是最有希望的成矿区段。

我国主要金矿类型中黄铁矿“电子-空穴心”特征及影响因素

通过对我国主要金矿类型中黄铁矿导电类型的分析表明,黄铁矿"电子 空穴心"与金矿床的成因类型具有密切的联系,华北地台太古代变基性火山岩中的金矿床(绿岩带型)、热水淋滤型(卡林型)金矿床,黄铁矿多为单一的"电子心"型导电。大多数产于中生代岩体中的中深脉状金矿、火山次火山岩中的金矿床,黄铁矿为"电子心"、"空穴心"混合型导电,个别的为单一的"空穴心"导电。黄铁矿的"电子 空穴心"受杂质成分As、Co、Ni在成矿背景中的丰度,进入黄铁矿晶格中的替代能力的差异、补偿类质同象现象、成矿时温度以及f(S2)等多种因素的耦合制约。

甘肃北山地区南金山金矿床隐爆角砾岩体的发现及成矿规律研究

地质研究发现,南金山金矿区出露的下石炭统白山组上岩组的部分岩石为隐爆角砾岩,其中厚层-块状变花岗质砂砾岩为隐爆岩浆角砾岩,厚层-块状变凝灰质砂砾岩为隐爆凝灰角砾岩。隐爆角砾岩体呈近EW向带状分布,隐爆岩浆角砾岩分布于岩体中部,构成岩体的内带,隐爆凝灰角砾岩对称分布于岩体南北两侧,构成岩体的外带。经矿床地质研究,提出了新的认识,认为该矿床的形成受隐爆角砾岩体及隐爆断裂构造的控制,金矿体分布于隐爆角砾岩体外带的隐爆凝灰角砾岩及隐爆断裂中;提出了隐爆角砾岩体外带成矿、对称成矿和双层成矿等3条矿体分布规律。采用EH-4连续电导率成像仪进行了深部地球物理测量,测量结果验证了隐爆角砾岩体控矿及其成矿规律。

预测水平管气—液环状流周向液膜厚度分布的理论模型

针对水平环状流液膜厚度沿周向分布的不对称性, 用5组双平行电导探针测量了水平管内气液环状流沿周向的瞬态液膜厚度,得到了平均液膜厚度沿周向的分布规律.分析了液膜向上输送的机理.为更为准确地预测液膜厚度, 综合考虑了扰动波抽吸作用机理、气体二次流机理及液滴沉降和携带机理; 通过量级比较和应力平衡的方法, 提出了一个预测液膜厚度沿周向分布的理论模型.数值模拟结果表明预测值与实验测量结果符合较好.

MD-1膜驱剂溶液的性质

分子沉积(MD)膜驱油技术是依靠MD膜驱剂在油藏体系的各种界面上单分子层静电吸附释放热量,从而提高原油采收率的新型技术。考察了MD 1膜驱剂溶液的电导率、粘度和其在原油中的分配。结果表明,MD 1膜驱剂属表面非活性物质,其水溶液不存在"胶束"状态;MD 1膜驱剂的加入不增加驱替流体的粘度,不改变油 水流度比,膜驱油机理与聚合物驱不同。随着MD 1膜驱剂质量浓度的增加,其相应油 水分配系数明显降低,MD 1膜驱剂质量浓度小于200mg/l时,其相应油 水分配系数随着质量浓度的增加明显降低,而浓度大于200mg/l时,油 水分配系数一般小于0 1;相同条件下,原油中的胶质和沥青质含量越多,MD 1膜驱剂在油、水两相间的分配系数越高。MD 1膜驱剂的油 水分配系数远小于1,说明其在油相中的溶解量很小。

新疆阿尔泰金矿带主要金矿类型、成矿规律及成矿预测

新疆阿尔泰金矿带金矿分布广泛,主要类型有火山晚期热液型金矿床、与韧性剪切带有关的金矿床。对不同类型金矿床基本成矿特征进行了研究,探讨了不同类型金矿床的控矿作用,在此基础上总结了阿尔泰金矿带主要金矿类型的成矿规律,对主要金矿深部进行了成矿预测,发现并圈出了矿床深部的矿化异常。

TerraTEM瞬变电磁系统在隐伏铁矿体上的勘查应用

介绍了TerraTEM瞬变电磁系统的性能和瞬变电磁探测的特点。通过在河南省2个隐伏铁矿上的勘查工作,分析该系统的瞬变电磁异常特征,结合钻孔的验证对比,证实该系统在隐伏铁矿上的勘查效果明显。

新疆布尔克斯岱金矿床成矿远景

新疆布尔克斯岱金矿床产于下石炭统黑山头组细碎屑岩中 ,矿体产出受EW向断裂构造控制。矿石类型主要为构造蚀变岩型。EH4连续电导率测量表明 ,该矿床深部存在明显的地球物理异常 ,异常长度大于 90 0m ,宽度大于 10m ,延伸大于 10 0 0m ,展示了金矿床深部具有良好的成矿前景 ,是一个有利的大型金矿找矿靶区。

导电聚吡咯／聚酯复合织物研究

采用吡咯气固相沉积聚合法制备导电聚吡咯／聚酯复合织物，研究了处理工艺对聚酯织物结构与性能的影响。结果表明，聚酯织物先经碱减量处理60 min，再经1.0 mol／L氧化剂处理30 min，吡咯单体气固相沉积聚合8次可制得具有较好导电性能的聚吡咯聚酯复合织物，其表面电阻约为330 Ω／cm，其力学性能的降低程度不大，聚吡咯均匀致密地沉积在聚酯织物表面。