L.P. Wang
,
B. Y Tang
,
X.B. Tian
,
YX.Leng
,
Q. YZhang
,
P.K.Chu
材料科学技术（英文）
Cerium dioxide, CeO2, is a potentially superior material in a myriad of areas, and many methods have been proposed to deposit single crystal CeO2 thin films. A novel fabrication technique utilizing dual plasma generated by metal vacuum arc (MEVVA) and radio frequency (RF) is discussed in this paper. We have recently conducted a systematic investigation to determine the optimal process window to deposit CeO2 thin films'on Si(100) substrates. The X-ray diffraction results show the existence of CeO2(100) in the as-deposited sample
关键词:
X.B. Tian
,
L.P. Wang
,
D. T.K.Kwok
,
B. Y Tang
,
P.K.Chu
材料科学技术（英文）
Plasma immersion ion implantation (PIII) is an excellent technique for the surf see modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the process and cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.
关键词:
Physics Letters A
The magnetic properties of the mixed ferro-ferrimagnetic compounds with (A(a)B(b)C(c))(y)D, in which A, B, C and D are four different magnetic ions and form four different sublattices, are studied by using the Ising model. And the Ising model was dealt with standard mean-field approximation. The regions of concentration in which two compensation points or one compensation point exit are given in c-a, b-c and a-b planes. The phase diagrams of the transition temperature T-c and compensation temperature T-comp are obtained. The temperature dependences of the magnetization are also investigated. Some of the result can be used to explain the experimental work of the molecule-based ferro-ferrimagnet ((NiaMnbFecII)-Mn-II-Fe-II)(1.5) [Cr-III (CN)6] - zH(2)O. (C) 2003 Elsevier B.V. All rights reserved.
关键词:
mixed ferro-ferrimagnet;Ising model;four sublattices;phase diagram;transition temperature;compensation temperature;magnetic-properties;prussian blue;alloy
陈伟荣
,
王清
,
程旭
,
张庆瑜
,
董闯
金属学报
在三元Fe-B-Y合金系中, 以团簇线判据设计了5个基础合金成分, 即5条成分线Fe8B3-Y, Fe8B2-Y, Fe83B17-Y, Fe6B-Y和Fe9B-Y与一条团簇线Fe12Y-B的交点. 在此基础上加入微量Nb和M(M=Ti, Hf, Ta, Mo, Ni和Sn)形成五元合金, 用铜模铸造方法制备出直径为3 mm的合金棒. 考虑到元素B和Y在合金制备过程中的损耗, 对每个合金进行了成分修正.在M=Ti, Hf, Ta和Mo时, 能够形成块体非晶合金的三元基础成分均接近Fe8B3-Y与Fe12Y-B两条团簇线交点成分, 表明其对应的基础团簇为Archimedes八面体反棱柱Fe8B3. 最佳非晶成分为(Fe69.9B24.6Y5.5)96Nb2Ti2,其Tg=944 K, Tx=997 K, Trg=0.666.当M=Ni和Sn时, 均没有得到块体非晶合金.
关键词:
团簇线
,
Fe-based bulk metallic glass
,
composition design
陈伟荣
,
王清
,
程旭
,
张庆瑜
,
董闯
金属学报
doi:10.3321/j.issn:0412-1961.2007.08.003
在三元Fe-B-Y合金系中,以团簇线判据设计了5个基础合金成分,即5条成分线Fe8B3-Y,Fe8B2-Y,Fe83B17-Y,Fe6B-Y和Fe9B-Y与一条团簇线Fe12Y-B的交点.在此基础上加入微量Nb和M(M=Ti,Hf, Ta,Mo,Ni和Sn)形成五元合金,用铜模铸造方法制备出直径为3 mm的合金棒.考虑到元素B和Y在合金制备过程中的损耗,对每个合金进行了成分修正.在M=Ti,Hf,Ta和Mo时,能够形成块体非晶合金的三元基础成分均接近Fe8B3-Y与Fe12Y-B两条团簇线交点成分,表明其对应的基础团簇为Archimedes八面体反棱柱Fe8B3.最佳非晶成分为(Fe69.9B24.6Y5.5)96Nb2Ti2,其Tg=944 K,Tx=997 K,Trg=0.666.当M=Ni和Sn时,均没有得到块体非晶合金.
关键词:
团簇线
,
铁基块体非晶合金
,
成分设计
Journal of Applied Physics
The magnetic properties of R2Co14B1-xCx (x=0, 0.5 and R=Y, Sm) compounds have been studied by measuring the temperature dependence of the easy- and hard-magnetization curves on magnetically aligned samples between 1.5 and 300 K for Y2Co14(B,C) and at 4.2 K for Sm2Co14(B,C). The magnetic anisotropy of Y2Co14B increases due to the substitution of C for B, whereas the saturation magnetization decreases. Between 1.5 and 300 K, the anisotropy field of Y2Co14B0.5C0.5 increases about 2 T and the Co moment decreases about 0.05mu(B). The anisotropy field Of Sm2Co14B also increases upon C substitution and the saturation magnetization decreases slightly. The ac susceptibilities of both SM2Co14B and Sm2Co14B0.5C0.5 exhibit anomalies that may arise from a spin reorientation within the basal plane.
关键词:
nd2fe14b;exchange;nd2co14b;r2fe14b;field
Fatigue & Fracture of Engineering Materials & Structures
Fatigue crack growth behavior in welded joints subjected to elastic-plastic shock waves was investigated using three-point-bend specimens. The results indicate that the fatigue crack growth rate is reduced in the affected region of elastic or plastic waves. The travel of a plastic stress wave reaches 10 to 13 mm depth, but the hardness in this region is not increased although the lattice distortion is high. The crack path morphologies were observed, and reasons for a decrease in crack growth rate are presented.
关键词:
Journal of Applied Physics
Y2Fe14B0.5C0.5 has the same tetragonal structure as Y2Fe14B with space group P4(2)/mnm. Magnetic properties of the Y2Fe14B0.5C0.5 compound have been studied using an extraction magnetometer with a maximum field of 6 T, in the temperature range from 1.5 to 300 K. By means of fitting the hard magnetization curves, the magnetocrystalline anisotropy constants K1, K2, and K3 were determined. It was found that although the magnetocrystalline anisotropy field (mu-0H-a) increases abnormally with increasing temperature as in the case of Y2Fe14B, the dependence of anisotropy constants on temperature is quite different from that of Y2Fe14B. K1 and K3 decrease slightly with increasing temperature. K2 increases abnormally with increasing temperature, which contributes to the abnormal dependence of anisotropy field on temperature. In addition, the substitution of carbon for boron leads to a reduction of 3d-3d interaction and spontaneous magnetization. In contrast, uniaxial anisotropy is increased by the addition of carbon below room temperature.
关键词:
alloys
杨广宇
,
刘咏
,
王岩
,
李建波
,
唐蓓
,
李慧中
中国有色金属学报
采用光学显微镜、扫描电镜及透射电镜研究微量B和Y对铸造Ti-AIl-Nb-W合金显微组织的影响.结果表明:Ti-47Al-4Nb-0.6W合金的基本凝固路线为L→β+L→(β+a)+L→(β+a)+γ→aa+γ→(a-γL)+γ→(a2+γ<,L>)+γ,添加微量B和Y并未改变其基本凝固路径;微量B元素在合金中以短棒状TiB2相存在,细化了铸造Ti-47Al-4Nb-0.6W合金的晶团尺寸及片层间距;微量稀土Y元素主要以Y2O3氧化物颗粒的形式分布于片层晶团界面处,在B和Y的共同作用下,合金的片层晶团尺寸以及片层间距进一步减小.
关键词:
TiAl基合金
,
显微组织
,
铸造合金
,
B
,
Y
