材料期刊网

NON CHROMATE CONVERSION COATING TREATMENT FOR MAGNESIUM ALLOY

A.P.Zeng , Y.Xue , Y.F.Qian and Z.J.Wang Shanghai Institute of Metallurgy , The Chinese Academy of Sciences , Shanghai 200050 , China

金属学报(英文版)

A no pollution organic acid based conversion coating solution MIS. No.1 has been examined as to its suitability as possible replacement for chromate containing formulations on magnesium alloys. Investigations have concentrated on the formation of passive film from simple MIS. No.1 solution using immersion. The morphology of passivated surfaces was examined using scanning electron microscopy (SEM). The corrosion resistance of the passivated surfaces and the painted surface was assessed using electrochemical techniques as well as humidity and salt fog tests. It was concluded that the surface treatment magnesium alloy by MIS.No.1 solution is more effective than that by chromate coating treatment, and the MIS.No.1 coating is also suitable for painting's pretreatment.

关键词: non chromate conversion coating , null , null , null

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Brief Outline of the Metallurgy Department of Kunming Institute of Technology

LIU Chunpeng Kunming Institute of Technology , Kunming 650093 , China.

材料科学技术（英文）

关键词:

Calculations of the spin-lattice coupling coefficients F-ij and Z(ij) for MgO : Co2+ crystal

Communications in Theoretical Physics

According to a uniform and simple method of calculating spin-lattice coupling coefficients and the perturbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d(7) ions in Cubic, tetragonal and trigonal octahedral crystal fields, the spin-lattice coupling coefficients F-ij (F-11, F-12, F-44), Z(ij) (Z(11), Z(12), Z(44)) and also g factor and hyperfine constant A for MgO:Co2+ are calculated by using the parameters obtained from the optical spectra without adjustable parameters. The calculated results show good agreement with the observed values. The difficulty in explaining the coefficients F-ij and Z(ij) is therefore removed.

关键词: spin-lattice coupling coefficients;electronic paramagnetic resonance;crystal- and ligand-field theory;Co2+;MgO crystal;superposition model;explanation;symmetry;ions;co2+;g11;g44

Na(Y1.5Na0.5)F6∶Eu3+的热稳定橙色发光及荧光增强

庞涛 , 周元

功能材料 doi:10.3969/j.issn.1001-9731.2017.04.023

采用简单的水热工艺制备了六方相Na(Y1.5 Na0.5)F6∶Eu3+荧光粉.300 K温度下利用394 nm光波长激发,观察到Eu3+的5Dn(n=0,1,2)→7 FJ(J=1,2,3,4)跃迁,对应主波长590 nm,色彩饱和度约为0.97.当温度升高到420 K时,仅观察到微小的色漂移.进一步拟合Ln(I0/I-1)和10 000/T的关系曲线,确定发光的热猝灭激活能约为0.324 eV.良好的热稳定性,表明Na(Y15Na0.5)F6∶Eu3+适合于功率器件的封装.在Na(Y1.5 Na0.5)F6∶Eu3+表面包覆二氧化硅后,可观察到Eu3+增强的发光,但这种荧光增强依赖于二氧化硅壳层的厚度.利用荧光增强与荧光猝灭的竞争模型解释了上述现象.

关键词: Na(Y1.5 Na0.5)F6∶Eu3+ , 热稳定性 , SiO2包膜 , 荧光增强

SOFC阴极材料(La_(0.85)Sr_(0.15))_y(Mn_(1-z)Cr_z)O_3的物理性能和化学稳定性

杨威 , 隋智通

材料研究学报

采用烧结法制备阴极材料(La0.85Sr0.15)y(Mn1z-Crz)O3(y=0.85;1;z=0.1,0.2).研究了多孔锰酸镧与致密ZrO2(8mol%Y2O3)界面的成分变化和显微形貌(La0.85Sr0.15)(Mn0.9Cr0.1)O3呈现高电子电导率、良好的热膨胀系数匹配和化学稳定性而(La0.85Sr0.15)MnO3未起到阻止界面退化的作用在1300～1500℃范围内Mn、La、Zr和Sr发生扩散,其中Mn的扩散明显

关键词: SOFC , lathanum manganite. chemical stability , thermal expansion , conductivity , null

RbLn2F7的水热合成及RbLn2F7:Eu3+(Ln=Gd,Y)的VUV光谱

由芳田 , 黄世华 , 王大伟 , 黄艳 , 徐建华

中国稀土学报

利用水热方法合成出RbLn2F7(Ln=Gd,Y,Er,Yb和Lu),均为六方RbEr2F7型结构.掺杂Eu3+离子样品的光谱表明水热产物中氧杂质含量极低.在RbGd2F7:Eu3+(0.5mol%)的激发光谱中只观测到Gd3+离子f-f跃迁,Eu3+离子的激发跃迁很弱.激发Gd3+离子到6IJ能级后,观测到Eu3+离子的特征发射,Gd3+离子与Eu3+离子之间存在能量传递过程.Eu3+离子的5D0→7F1和5D0→7F2跃迁发射较强,表明稀土离子在六方RbLn2F7中处于非中心对称的格位.

关键词: RbLn2F7 , 水热合成 , 真空紫外(VUV) , 氟化物 , 能量传递 , 稀土

Y0.78Yb0.2Er0.02F3多孔纳米粒子的合成与上转换发光

杨梅 , 刘其鹏 , 李东风 , 尤洪鹏 , 洪广言

中国稀土学报

以Y2O3,Yb2O3,Er2O3,NH4F等试剂为原料,采用水热法在180 ℃下保温10 h获得了NH4Y1.56Yb0.4Er0.04F7球形纳米粒子. 所获得的纳米粒子在氮气保护下400 ℃灼烧2 h,制备出Y0.78Yb0.2Er0.02F3纳米粒子. 利用Scherrer公式计算出NH4Y2F7:Yb3+,Er3+和YF3:Yb3+,Er3+的粒径分别为65.8和68.3 nm. TEM照片展示粒子近球形,其大小与Scherrer公式计算结果一致. TEM还揭示每个粒子上面应带有许多小孔. 氮气吸附脱附实验进一步证实了粒子上存在小孔. 在980 nm的红外激光激发下,NH4Y1.56Yb0.4Er0.04F7不发光,而Y0.78Yb0.2Er0.02F3发出明亮的绿光,表明所获得的Y0.78Yb0.2Er0.02F3具有强的上转换发光.

关键词: NH4Y1.56Yb0.4Er0.04F7 , Y0.78Yb0.2Er0.02F3 , 纳米粒子 , 水热法 , 上转换发光 , 稀土

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

Application of Microwave Radiation to Extractive Metallurgy

LIU Chunpeng XU Yousheng HUA Yixin Kunming Institute of Technology , Kunming , 650093 , China.

材料科学技术（英文）

In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.

关键词: microwave radiation , null , null , null