材料期刊网

IN SITU TEM OBSERVATION OF NANOSILICON FIBRE GROWTH

F.C.Zhang 1) , B.T.Hu 1) , L.X.Zhang 1) and C.F.Lin 2) 1) Department of Materials Science and Engineering , Yanshan University , Qinhuangdao 066004 , China 2) Institute of Metal Research , The Chinese Academy of Sciences , Shenyang 110015 , China

金属学报(英文版)

Nano silicon particles can be become nano fibre under low energy electron beam bombarding. The formation of the nano silicon fibre include two stages. At first, on the nano silicon particle surface many silicon atoms are gasified, then these silicon atoms deposit in the place where have more charge on account of the static electrical absorption and the point effect of the charge accumulation , these atoms grow into non crystalline silicon fibres. The second stage is the non crystalline silicon fibres crystallizing. Its crystallizing temperature is about 180℃. The growth mechanism of the nano silicon fibre is vapour solid mode.

关键词: nano fibre , null , null

Mg-14Li-1Al-0．1Ce合金在卤素溶液（NaX，X=F，C1，Br和I）中腐蚀行为的研究

马毅斌 , 李宁 , 黎德育 , 张密林 , 黄晓梅

腐蚀学报（英文）

用电化学方法研究了Mg-14Li-1Al-0．1Ce合金在卤素溶液（NaX，X=F，C1，Br和I）中的腐蚀行为并用失重法测定其腐蚀速率，用扫描电镜（SEM）观察腐蚀后的表面形貌，利用XRD检定腐蚀产物的相组成．结果表明，合金在卤素溶液中的腐蚀速率由低到高的顺序是：NaF〈NaI〈NaBr〈NaCl．经过48h腐蚀后，合金在NaCl、NaBr和NaI溶液中的腐蚀产物层的组分为Mg（OH）2，Li3Mg7和Li0.92Mg4.08，而在NaF溶液中的腐蚀产物层的组分为Li3Mg7和Li0．92Mg4．08．此外，合金在NaF溶液中的电化学活性非常低，出现了钝化现象．电化学阻抗谱表明合金腐蚀产物层不能起到防止基体腐蚀的作用．

关键词: 镁锂合金 , 腐蚀 , 卤化钠 , EIS , XRD

STATISTICAL EVALUATION OF CRITICAL INCLUSION FACTOR FOR SECONDARY RECRYSTALLIZATON IN 3%Si STEEL Lecturer,Department of Materials Engineering,Southwestern Jiaotong University,Chengdu 610031,China

LI Shuchen Southwestern Jiaotong University , Chengdu , ChinaCHEN Mengzhe KE Jun University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

On the basis of statistical data of MnS in the conventional 3% Si steel sheeets after various annealing processes,the critical inclusion factor has been evaluated to be 20 mm~(-1).The inhi- bition of MnS to grain growth has been exactly described.

关键词: 3%Si steel , null , null

Service Performance of Engineering Materials

Andrej Atrens

材料科学技术（英文）

Corrosion research by Atrens and co-workers has made significant contributions to the understanding of the service performance of engineering materials. This includes: (1) elucidated corrosion mechanisms of Mg alloys, stainless steels and Cu alloys, (2) developed an improved understanding of passivity in stainless steels and binary alloys such as Fe-Cr, Ni-Cr, Co-Cr, Fe-Ti, and Fe-Si, (3) developed an improved understanding of the melt spinning of Cu alloys, and (4) elucidated mechanisms of environment assisted fracture (EAF) of steels and Zr alloys. This paper summarises contributions in the following: (1) intergranular stress corrosion cracking of pipeline steels, (2) atmospheric corrosion and patination of Cu, (3) corrosion of Mg alloys, and (4) transgranular stress corrosion cracking of rock bolts.

关键词: Stress corrosion cracking , null , null

Superconductivity modulated by internal pressure in Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) compounds

Superconductor Science & Technology

It is shown that the superconductivity in Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) compounds can be modulated by internal (chemical) pressure. The internal pressure is induced by Gd substitution for Ce in CeFeAsO(0.84)F(0.16), which compresses the crystal lattice. The temperature dependences of resistivity and magnetization show that the superconducting-transition temperature T(c) is enhanced from 40 K for CeFeAsO(0.84)F(0.16) to 47.5 K for Ce(0.6)Gd(0.4)FeAsO(0.84)F(0.16). The increase and subsequent decrease of Tc upon application of external pressure, as observed previously in LaFeAsO(0.89)F(0.11), is entirely confirmed by the modulation of Tc of the Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) superconductors by internal pressure.

关键词: layered quaternary compound;43 k;iron

Structural evolution of Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) superconductors

Journal of Applied Physics

Structural parameters have a critical impact on superconductivity in iron-based oxypnictide superconductors. Structural evolution study was performed on Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) superconductors by the analysis of the x-ray diffraction patterns with Rietveld refinement. Substitution of Gd for Ce generates internal pressure that compresses the crystal lattice. The contraction of the c axis is also indicated by the reduction of Ce/Gd-As and Ce/Gd-O/F distances, while there is a slight increase in the As-Fe-As block size, which is compensated by a large reduction in the Ce/Gd-O/F-Ce/Gd block with Gd substitution. The diagonal Fe-As-Fe angle for Ce(0.6)Gd(0.4)FeAsO(0.84)F(0.16), with the highest T(c) among Ce(1-x)Gd(x)FeAsO(0.84)F(0.16) compounds, is 111.13 degrees. It is close to the ideal value of 109.47 degrees for the perfect FeAs tetrahedron, which is situated in the region of Fe-As-Fe bond angles where RFeAsO compounds tend to have the highest T(c). (C) 2011 American Institute of Physics. [doi:10.1063/1.3565408]

关键词: layered quaternary compound;high-temperature superconductivity

Investigations of EPR g Factors and Rhombic Distortion for the Rhombic Cu2+ Centers in K2Zn1-x Cu (x) F-4 Crystals at Low Temperature

Applied Magnetic Resonance

The electron paramagnetic resonance g factors g (i) (i = x, y, z) of two rhombic Cu2+ centers, Cu2+(II) and Cu2+(III), in K2Zn1-x Cu (x) F-4 crystals found at low temperature are calculated from the complete diagonalization (of energy matrix) method based on the cluster approach. The calculations show that the ground state wave function of the two rhombically compressed Cu2+ centers is with a small admixture of . The rhombic distortions for both Cu2+ centers are obtained from the calculations. The results are discussed.

关键词: electron-paramagnetic-resonance;atomic screening constants;hyperfine;parameters;gyromagnetic factor;spin resonance;scf functions;field;copper(ii);dependence;spectra

c轴倾斜CuCr1-xMgxO2(x=0,0.02)薄膜的外延生长

樊堃 , 虞澜 , 秦梦 , 刘丹丹 , 康冶 , 宋世金 , 陈亮维

人工晶体学报

采用脉冲激光沉积技术在0°,5°,10°c轴倾斜α-Al2 O3 (0001)衬底上制备出c轴生长CuCr1-xMgx O2(x=0,0.02)薄膜.用x射线衍射Φ扫描分析薄膜与衬底(000l)晶面的结晶取向关系为＜1100＞ CuCrO2∥＜1120＞α-Al2O3,并进一步通过θ扫描、2θ扫描表征5°和10°c轴倾斜衬底上CuCrO2薄膜与衬底(0006)晶面之间的倾斜角度差值由0.43°增加到1.76°,得到薄膜c轴外延性随衬底倾斜角变大而变差.AFM观察生长在α-A12 O3 (0001)衬J芪上的CuCr1-xMgxO2薄膜为层状形貌,且倾斜衬底上薄膜晶粒尺寸减小,晶界增加.p-T测量曲线表明:相比平直衬底,10°倾斜衬底上CuCrO2薄膜的电阻率略有升高,这是由于倾斜衬底上薄膜结晶质量较差及晶界对载流子散射增强所致,与XRD和AFM结果相一致.

关键词: CuCr1-xMgxO2薄膜 , 脉冲激光沉积 , c轴倾斜 , 外延性

(A~ⅢB~V)_(1-x)C_(2x)~Ⅳ 型三元合金的有序结构

王世范 , 倪军 , 段文晖

材料研究学报

本文将原子位形几率波理论推广到三元复式格子体系,研究了(A~ⅢB~Ⅴ)_(1-x)C_(2x)~(Ⅳ)型合金最稳定超晶格的原子排列,由理论得到十九种基态有序结构,揭示了原子有序分布的形成规律。

关键词: 原子位形几率波 , material design , ordered structure

MAGNETIC PROPERTIES OF Nd_2(Fe_(1-x)M_x)_(14)B(M=C,Si)ALLOYS

XING Feng JIANG Chao HE Wenwang Department of Physics , Peking University , Beijing , China [Originally published in ACTA METALL SIN (CHINESEEDN) 24 (5) 1988pp B348—B352 , received 22 October 1986:in revised form 8 May 1987]

金属学报(英文版)

The magnetic properties of Nd_2(Fe_(1-x)M_x)_(14)B(M=C and Si) compounds have been investi- gated.Substituting Fe by small amount of metalloid C and Si atoms,the compounds are in tetragonal structure and have uniaxial anisotropy.The substitution of C for part of Fe de- creases the Curie temperature of the compounds and the intrinsic coercivity of bond samples at low temperature.The replacement of Fe by Si makes the Curie temperature increase with a maximum at the vicinity of x=0.15.When the range of the content of Si is 0≤x≤0.10,the coercivity distinctly increases at room temperature.from 62.7 kA/m at x=0 to 138.7kA/m at x=0.06,where the residual magnetization has a maximum:in the mean time the saturation magnetization decreases only by a small amount.

关键词: Nd-Fe-B alloy , null , null