材料期刊网

Melting Characteristics of Iron Ore Fine During Sintering Process

LI Hongge , ZHANG Jianliang , PEI Yuandong , ZHAO Zhixing , MA Zejun

钢铁研究学报(英文版)

The whole melting curve of iron ore during sintering process was obtained, and the melting characteristics of iron ore were defined and explained. The whole melting process of mixture, mixed by iron ore and CaO reagent at basicity of 20 and 40, respectively, was observed using a SiC heating furnace with camcorder unit, and the melting curves of mixture that were relative height vs temperature curves were obtained. Besides, the melting characteristics of iron ore during sintering were introduced through defining some points in the melting curves, such as liquid forming temperature, inflexion temperature and flowing temperature, and the meaning of different shapes of the melting curves was clarified.

关键词: iron ore , sintering , melting characteristic , melting curve

Zn2+、Ge4+的取代对Li5AlSi2O8的影响

刘慧勇 , 王文继

功能材料

尝试以叶腊石为基体,通过高温固相反应,合成通式为Li5+xAl1-xZnxSi2-2xGe2xO8(x=0.0～1.0)系统锂快离子导体.X射线粉末衍射表明当x≤0.3时体系仍维持原有的Li5AlSi2O8结构(正交晶系);x＞0.5时结构发生明显变化,体系转变成Li6ZnGe2O)8.红外检测显示当x≥0.1红外谱图中出现Li2CO3吸收峰,表明在室温下体系中的Ge4+吸收空气中的CO2而发生分解反应.交流阻抗技术测试交流阻抗表明当温度大于200℃时体系有较高的电导率,最高时为1.11×10-2S/cm(400℃,x=1.0),x≤0.5时离子电导率很低,且不随温度变化.

关键词: 快离子导体 , 叶腊石 , 体系

锂离子电池负极材料Ge4+掺杂Li4Ti5O12的制备及其电化学性能研究

邱彩霞 , 袁中直 , 刘玲 , 程思洁 , 刘金成

无机材料学报 doi:10.3724/SP.J.1077.2013.12525

以Ti(OC4H9)4、CH3COOLi·2H2O和GeO2为原料,采用溶胶-凝胶法合成了尖晶石型Li4Ti5-xGexO12(x=0、0.05、0.1、0.15)电极材料.通过X射线衍射(XRD)、扫描电镜(SEM)、充放电测试、循环伏安(CV)以及交流阻抗对材料进行结构、形貌及电化学性能表征.研究结果表明,适量Ge4+掺杂不会改变Li4Ti5O12的尖晶石结构,但对其颗粒尺寸和形貌均产生影响.由于掺Ge4+后样品的颗粒尺寸减小,使得Ge4+掺杂Li4Ti5O12倍率性得到不同程度的提高.其中Li4Ti4.9Ge0.1O12显示出较好的倍率性和循环稳定性,0.2C下的首次放电容量为172.43 mAh/g,5C下循环100次后比容量为140.62 mAh/g,容量保持率为97.3％.

关键词: 锂离子电池 , Li4Ti5O12 , Ge4+掺杂 , 倍率性

LIQUIDUS OF SYSTEM Ag-Cu-Ge

LIU Shuqi , YI Tao , Peking University , Beijing , China

金属学报(英文版)

The diagram of Ag-Cu-Ge system was constructed from the investigation of 13 internal sec- tions by DTA heating as well as cooling curves in an atomsphere of dry N_2 . The phase dia- gram is subdivided into two pseudo-ternary systems shown as Ag-Cu-Cu_3Ge and Ag-Cu_3Ge-Ge. Both systems belong to simple eutectic type. The ternary eutectic points lie in." E_1, Ag(22.0)-Cu(58.8)-Ge(19.2), 632℃ and E_2 , Ag(44.3)-Cu(29.5)-Ge(26.2), 533℃. The three side binary systems were redetermined.

关键词: phase diagram , null , null

Crystal structures of compounds in the pseudobinary system Gd5Ge4-La5Ge4

Journal of Alloys and Compounds

Crystal structures of compounds at ambient temperature in the pseudobinary system Gd5Ge4-La5Ge4 were studied by X-ray powder diffraction (XRD). There exist three single-phase regions in this system. The crystal structure of Gd5Ge4, La5Ge4 and Gd3La2Ge4, which are prototype compounds in three phase regions, respectively, were reported. The Gd5Ge4 and La5Ge4 crystallize in the orthorhombic Sm5Ge4-type structure with space group Pnma. The ternary intermediate compound Gd3La2Ge4, which is determined for the first time, crystallizes in the monoclinic Gd5Si2Ge2-type structure with space group P112(1)/a. The Rietveld powder diffraction profile fitting technique was used for the refinement of crystal structure. The lattice parameters, atomic occupations, interatomic distances of the Gd5Ge4, La5Ge4 and Gd3La2Ge4 compounds were derived. (C) 2003 Elsevier B.V. All rights reserved.

关键词: rare earth compounds;crystal structure;X-ray diffraction;phase-relationships;gd-5(si2ge2);transition;silicon

First-principles study of lithium adsorption on Si(100)2 x 1 and Ge(100)2 x 1 surface at 1.0 monolayer coverage

Chemical Physics

First-principles calculations based on density functional theory have been carried out to determine the atomic structure and electronic properties of the Si(100)2 x 1-Li and Ge(100)2 x 1-Li adsorption systems at 1.0 monolayer (ML) coverage. For the Si(l 00)2 x 1-Li chemisorption system, the lowest energetic configuration is that one Li atom resides at the T3' (which is displaced along the positive y-axis from the valley bridge (T3) site by 0.90 angstrom) and the other resides at pedestal (HH) site. For the Ge(l 00)2 x 1-Li chemisorption system, the most stable configuration is found to be that one Li atom resides at HH site and the other one will penetrate deeply into the substrate surface. Chemisorption of the lithium atoms is found to result in a minimum energy configuration characterized by symmetric dimers in agreement with the results of high-resolution core-level photoelectron spectroscopy. The adsorption systems show semiconducting surface characterization. (c) 2006 Elsevier B.V. All rights reserved.

关键词: first-principles calculation;lithium adsorption;atomic structure;angle-resolved photoemission;energy electron-diffraction;core-level;spectroscopy;si(001)2x1-k surface;photoelectron-spectroscopy;alkali-metals;ab-initio;li;resolution;atoms

Thermodynamic Analysis of Ag_3Ge Phase Formation

O.P.Pandey(School of Basic and Applied Sciences , Thapar Institute of Engineering and Technology Patiala-147 001 , India )S.N.Ojha and S.Lele(Dept. of Metallurgical Engineering , Banaras Hindu University , Varanasi-221 005 , India)

材料科学技术（英文）

In the present work a thermodynamic model is presented for the nucleation of metastable Ag3Ge phase from the undercooled melt in Ag-Ge alloy system. It is shown that under kinetically induced favourable condition, nucleation of a single phase compound with an approximate stoichiometry Ag3Ge has greater affinity for nucleation over Ag and Ge based phases requiring diffusion in the liquid.

关键词:

THE EVOLUTION OF TECHNOLOGY DEVELOPMENT AT GE CORPORATE R & D

T.B.Cox(GE Corporate Research & Development , Niskayuna , NY 12309 , USA Manuscript received 26 August 1996)

金属学报(英文版)

A brief review of the nearly 100 year history of Corporate Researeh and Development at GE is presented. Observations on the changing nature and relevance of industrial research are discussed. Examples of current technology projects for aircraft engine materials are reviewed. Emphasis of these projects is placed on high performance,low cost and high quality.

关键词: :spray forming , null , null

ELECTRONIC-STRUCTURE AND MAGNETISM OF FE-GE INTERFACES

Journal of Physics-Condensed Matter

The local electronic density of states (LDOS) has been calculated for Fe-Ge(110), Fe-Ge(111) and Fe-Ge(100) interfaces and neighbouring atomic planes using the recursion method. Interface states are found to exist within the mutual gaps of the constituent atoms and strongly depending on the local atomic environments. The most excess LDOSS are found for Fe-Ge(111) interface and the least for Fe-Ge(110). The magnetic moments for Fe atoms are found to decrease when the Fe layer approaches the interface boundary, which is in accord with the experiments. The electron spin polarization parameters evaluated from the LDOS are qualitatively consistent with experimental measurements.

关键词: spin polarization;surface magnetization;recursion method;states;iron;films;ni

Fabrication of uniform Ge-nanocrystals embedded in amorphous SiO(2) films using Ge-ion implantation and neutron irradiation methods

Applied Physics Letters

Uniform Ge-nanocrystals (Ge-ncs) embedded in amorphous SiO(2) film were formed by using (74)Ge(+) ion implantation and neutron transmutation doping (NTD) method. Both experimental and theoretical results indicate that the existence of As dopants transmuted from (74)Ge by NTD tunes the already stabilized (crystallized) system back to a metastable state and then activates the mass transfer processes during the transition form this metastable state back to the stable (crystallized) state, and hence the nanocrystal size uniformity and higher volume density of Ge-ncs. This method has the potential to open a route in the three-dimensional nanofabrication. (C) 2011 American Institute of Physics. [doi:10.1063/1.3553770]

关键词: transmutation-doped gaas;electrical-properties;misfit dislocations;lasers go;silicon;films