材料期刊网

S. Kubono , 何建军 , H. Yamaguchi , D. M. Kahl , S. Hayakawa , T. Teranishi , S. Cheribini , M. Gulino , Y. K. Kwon , T. Hashimoto , Y. Wakabayashi , N. Iwasa , S. Kato , T. Komatsubara , D. N. Binh , L. H. Khiem , N. N. Duy , T. Kawabata , C. Spitaleri , G. G. Rapisarda , M. La Cognata , L. Lamia , R. G. Pizzone , S. Romano , A. Coc , N. de Sereville , F. Hammache , G. Kiss , S. Bishop

原子核物理评论 doi:10.11804/NuclPhysRev.33.02.212

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La~(3+)取代对M型锶铁氧体磁性能的影响

高华敏 , 李明玲 , 邓玉新 , 邱士星 , 周丹

兵器材料科学与工程 doi:10.3969/j.issn.1004-244X.2010.01.020

溶胶-凝胶法制备的Sr_(1-x)La_(x)Fe_(12)O_(19)样品,用XRD、VSM和TEM研究了La~(3+)取代量对样品结构和磁性能的影响.实验发现,合适的La~(3+)取代量能很明显提升样品的比饱和磁化强度和内禀矫顽力,在取代量x=0.15,于850℃空气中热处理时得到理想的磁性能σ_s=74.1 Am~2/kg,H_(cj)=498.4 kA/m.

关键词: 溶胶-凝胶法 , M型铁氧体 , La~(3+)取代 , 磁性能

La-Co替代的M型永磁铁氧体

王亦工 , 陈华辉 , 张婷

功能材料

对La-Co替代的M型高性能永磁铁氧体进行了详细介绍,包括材料制备的工艺特点,成分,显微结构,材料的内禀参数,技术磁性能以及温度特性等.研究结果表明:最优化组分为Sr0.7La0.3Fe11.7Co0.3O19的M型永磁铁氧体的饱和磁化强度Ms(298K)比SrFe12O19永磁铁氧体的大1%～3%,磁晶各向异性场Ha大16.8%,磁晶各向异性常数K1大16.7%,磁性能:Br=450mT,Hcj=384kA/m,(BH)max=38.6kJ/m3.

关键词: M型永磁铁氧体 , La-Co替代 , 工艺 , 磁性能

La0.5M0.5 MnO3(M=Sr,Ba)的水热合成与表征

余晓满 , 方军 , 李仁文

低温物理学报

我们用水热法合成了钙钛矿锰氧化物La0.5M0.5MnO3(M=Sr,Ba)系列样品,研究了制备条件对结构、形貌和磁性的影响.

关键词: La0.5Sr0.5MnO3 , La0.5Ba0.5MnO3 , 水热合成

固相法合成La2Ni0.5M0.5O4+δ(M=Co,Cu)材料及电性能

高文元 , 孙俊才 , 刘扬

功能材料

使用金属氧化物La2O3,NiO,CuO和Co2O3作为原料,固相反应法能够合成出具有K2NiF4型结构单一相的、且晶粒尺寸在35～50nm范围的La2Ni0.5M0.5O4+δ(M=Co,Cu)粉料,用XRD、SEM和直流四极探针电导测试法研究了合成La2Ni0.5M0.5O4+δ(M=Co,Cu)粉料的煅烧工艺条件和掺杂元素对电性能的影响以及粉料的颗粒形貌.随着煅烧温度的升高和保温时间的延长,晶粒尺寸在不断长大;合成的粉料在1300℃烧结5h后所有样品的电导率在空气条件下于100～800℃范围内都在增加.掺杂C0或Cu后的材料La2NiO4+δ的电导率均有增加,但掺杂Co后材料电导率要大于掺杂Cu的电导率.为此确定La2Ni0.5M0.5O4+δ(M=Co,Cu)类粉料固相法合成的适宜煅烧条件为1400℃下保温时间14h.

关键词: K2NiF4型结构 , LLa2Ni0.5M0.5O4+δ , 晶粒尺寸 , 掺杂元素 , 电导率

First principles study of the alloying effect on chemical bonding characteristics of helium in La-Ni-M tritides

Materials Science and Engineering B-Solid State Materials for Advanced Technology

The alloying effect on the electronic structure of La-Ni-M tritides is investigated using the first principles discrete variational X alpha(DV-X alpha) method. The calculated results show that the covalent interaction between atoms will play a much more important role in studying the alloying effect on chemical bonding characteristics in La-Ni-M tritides than ionic interaction. It is also found that in La-Ni-M tritides helium forms stronger covalent bonds with the weaker hydride forming elements than La. By analyzing the relation between the binding energy difference and bond order, our study indicates that after some alloying elements substituting for Ni locating in 3g site in tritides, the helium retention capability becomes stronger, changes as the following sequence: Al > Cr > Mn > Fe > Co > Ni, and is also very distinct for Cu although the chemical bonding between Cu atom and Ni atom is degraded drastically. (c) 2005 Published by Elsevier B.V.

关键词: tritides;electronic structure;chemical bonding;helium retention;iron grain-boundary;intermetallic compounds;electronic-structures;neutron-scattering;hydrogen storage;metal tritides;al tritides;hydrides;dynamics;behavior

中间合金合成 La2M gNi9合金及其储氢性能

陈朝轶 , 杨峰 , 陈辉林 , 刘静

功能材料 doi:10.3969/ji.ssn1.001-97312.0151.70.24

针对La‐M g‐Ni系储氢合金制备过程中存在易氧化、挥发及成本高等问题，提出采用熔盐保护熔炼法制备的La‐M g中间合金为原料，利用磁场辅助烧结合成技术制备 La2 MgNi9合金。结果显示，该方法可获得单相 PuNi3型结构的（La ，Mg）Ni3合金；1 T磁场下制备的合金最大吸氢容量为1．490％（质量分数），吸放氢动力学性能优异；磁场对合金的脱附热行为没有明显影响。

关键词: 储氢 , 中间合金 , 磁场 , 吸放氢性能

Improvement of hydrogen storage properties of La0.6M0.4Ni4.8Mn0.2 alloys

材料科学技术（英文）

Investigation has been carried out to find the effects of Nd substitution and Cu addition on the hydrogen storage properties of AB(5)-type alloy with a multicomponent La0.6M0.4Ni4.8Mn0.2 (M=Y, Nd) system. La0.6Y0.4Ni4.8Mn0.2, which was used in an air-conditioning system, showed poor hysteresis and sloping characteristics, which led to a decrease concerning the coefficient of performance of the system. By the substitution of Nd for Y, the hydrogen storage capacity increased, and the plateau pressure decreased a little, but the hydrogen absorption kinetics decreased dramatically. Cu addition can effectively improve the kinetics of hydride formation without changing the hydrogen storage capacity of La0.6Nd0.4Ni4.8Mn0.2. It has been found that La0.6Nd0.4Ni4.8Mn0.2Cu0.1 alloy showed good hydrogen storage characteristics for metal hydride air-conditioning system. The results showed that, for each component of La0.6M0.4Ni4.8Mn0.2, the effective hydrogen storage capacity increased with decrease of the unit cell parameter c/a and the hydrogen absorption plateau pressure increased with decrease of the parameter a.

关键词: metal hydride;air-conditioning system;sloping;hysteresis;kinetics;chemical-bond;absorption;stability;kinetics;samples;lani5

La0.6Nd0.4Ni4.8Mn0.2M0.1(M=Cu,Zr)合金的贮氢性能研究

李慎兰 , 程宏辉 , 邓小霞 , 吕曼祺 , 陈德敏 , 杨柯

稀有金属材料与工程

系统研究了非化学计量比合金La0.6Nd0.4Ni4.8Mn0.2M0.1(M=Cu,Zr)的贮氢性能.结果表明,添加Cu能提高合金的平台压力,减轻滞后效应:而添加Zr能够有效提高合金的动力学性能和抗粉化性能,降低平台压力.但Cu和Zr的添加使贮氢容量有所降低.研究表明,XRD(111)主峰半高宽FWHM值及晶格常数a/c值与合金的滞后因子有相同的变化趋势,平台压力、吸氢焓变与晶胞参数a有很好的线性关系.

关键词: 贮氢合金 , 非化学计量比 , 压力-成分等温线 , 动力学 , 抗粉化性能

Structural stability and structural imitation of La2Co17-xMx (M = Mn, Mo, Nb, Ti, V, Al, Cr, Ni and Si)

European Physical Journal B

The structural stability of La2Co17- xMx ( M = Mn, Mo, Nb, Ti, V, Al, Cr, Ni and Si) based on the interatomic potential has been studied. The calculated site preference of the third element M is found to be the 6c site, which is in agreement with the experiments. In the calculations, if the crystal cohesive energy of La2Co16Mn is taken as the highest one in the crystallization of La2Co17- xMx, the lowest content x of the third element M ( M = Mn, Mo, Nb, Ti and V) required to stabilize La2Co17- xMx, is near that found in the experiments. The differences of the cell parameters between the calculated and the experimental values are less than 0.4%. The differences of the atomic parameters for Co ( or M) between the calculated and the experimental values are about or even smaller than 1%, and that of La is about 3%. Because the energies of La( Co1-xAlx)(13) are lower than those of La-2(Co1-xAlx)(17), La-2(Co1- xAlx)(17) could not be formed in the experiments. In the calculations, with either a range of deformation of the structure or the reconstruction of the initial structure La2Co17 from LaCo5, the same results including the cohesive energy curves and the crystallographic parameters can be retrieved after the action of the interatomic potentials.

关键词: uniaxial magnetocrystalline anisotropy;magnetic-properties;intermetallics