Magnetic Properties of Erbium Gallium Gallate under High Magnetic Field

A theoretical investigation on the magnetic properties of rare-earth Er3+ in Er3 Ga5 O12 was reported. The average magnetic moments(M) for applied magnetic field H parallel to the [001 ], [ 100], [ 110], [ 111 ] direction was studied based on the quantum theory. Temperature dependence of the magnetic properties is analyzed for H applied parallel to the [ 100] and [ 111 ] crystallographic directions. The magnetization decreases with increasing temperature,showing good agreement with thermal effect. A strong anisotropy of the magnetization is found under high magnetic field, but when the magnetic field is small, M and H are proportional.     

Perspectives on Permanent Magnetic Materials for Energy Conversion and Power Generation

Permanent magnet development has historically been driven by the need to supply larger magnetic energy in ever smaller volumes for incorporation in an enormous variety of applications that include consumer products, transportation components, military hardware, and clean energy technologies such as wind turbine generators and hybrid vehicle regenerative motors. Since the 1960s, the so-called rare-earth “supermagnets,” composed of iron, cobalt, and rare-earth elements such as Nd, Pr, and Sm, have accounted for the majority of global sales of high-energy–product permanent magnets for advanced applications. In rare-earth magnets, the transition-metal components provide high magnetization, and the rare-earth components contribute a very large magnetocrystalline anisotropy that donates high resistance to demagnetization. However, at the end of 2009, geopolitical influences created a worldwide strategic shortage of rare-earth elements that may be addressed, among other actions, through the development of rare-earth-free magnetic materials harnessing sources of magnetic anisotropy other than that provided by the rare-earth components. Materials engineering at the micron scale, nanoscale, and Angstrom scales, accompanied by improvements in the understanding and characterization of nanoscale magnetic phenomena, is anticipated to result in new types of permanent magnetic materials with superior performance.     

Structure and Magnetic Properties of LaCo_(13-X)M_X Intermetallic Compounds

ＳｔｒｕｃｔｕｒｅａｎｄＭａｇｎｅｔｉｃＰｒｏｐｅｒｔｉｅｓｏｆＬａＣｏ＿（１３－Ｘ）Ｍ＿ＸＩｎｔｅｒｍｅｔａｌｌｉｃＣｏｍｐｏｕｎｄｓＷＵＪｉａｎＭｉｎ；ＬＩＦｅｎｇ；ＴＡＩＬｉＣｈｉａｎｄＺＨＥＭＧＱｕｎＳｔｒｕｃｔｕｒｅａｎｄＭａｇｎｅｔｉｃＰ...     

纳米复相稀土永磁材料研究进展

综述了纳米复相稀土永磁材料的研究现状;详细介绍了纳米复相永磁体的制备方法及磁性能,在粘结磁体、快淬磁体和磁控溅射磁体的基础上,又详细介绍了制备大块致密磁体的方法:热压法和热挤压法.分析了各种制备方法的优缺点;论述了添加合金元素和热处理工艺对磁性能的影响.并对纳米复相稀土永磁材料的研究前景作了展望.     

LaCo13—xMx金属间化合物的结构和磁性

在任何已知的稀土中间相化合物中,LaCo_(13)具有最高的3d金属含量,且其饱和磁化强度很高为1.03 MA/m居里温度高达1318 K,不幸的是它是立方结构,不存在适合于永磁应用所必须时各向异性。本文对LaCo_(13-x)Si_x(x=2,4)和LaCo_(13-x)Ge_x(x=2,2.5,3,4)金属间化合物的结构和磁性能进行了研究,发现对LaCo_(13-x)Si_x当x=4和LaCo_(13-x)Ge_x当x=3,4时,其晶体结构为四方结构但晶格常数a,c的差值很小。对于LaCo_(13-x)Ge_x为得到该结构所需的时效温度很严格。磁性测量发现它们的居里温度都较高,但室温饱和磁化强度随x增加大大降低。     

磁场退火对无取向硅钢磁性能的影响

为了研究退火温度、磁场强度、磁场方向及退火时间等对低牌号无取向硅钢磁性能和组织的影响,在正交试验的基础上,对无取向硅钢进行不同条件的退火处理,通过对磁性能数据的正交分析,优选出最佳的工艺参数。研究结果表明:退火温度和磁场强度是影响试验钢比饱和磁化强度的主要因素,磁场强度与退火时间对剩余磁化强度也有显著的影响。当加热温度在800℃、施加磁场强度为3 T时,调整施加磁场的方向与退火时间可以使无取向硅钢的比饱和磁化强度、比剩余磁化强度分别达到260.7 emu/g、18.265 emu/g。     

Phase and Microstructural Analysis of Hot Rolled FeNi42 Sheet,its Response in Magnetic and Mechanical Properties

Inclusions unavoidably existing in steels and consequently also in final products obtained by e.g. rolling markedly affects the physical properties. This paper is devoted to investigation of FeNi42 steel hot rolled into a sheet form. The structural and phase analysis is done by scanning electron microscopy, X‐ray diffraction, and Mössbauer spectroscopy completed by magnetic and hardness measurements. The results yield an inhomogeneous nickel distribution in the sheet resulting in a formation of the intermetallic Ni₃Fe phase. A depletion of sheet surface by nickel leads to an intensive surface oxidation; its thickness increases in the direction of sheet edges. The non‐metallic oxide inclusions are concentrated predominantly at grain boundaries, which contribute to an easier cracking. The formation of Ni₃Fe affects a small increase in saturation magnetization. The oxides and consequently cracks formation cause magnetic hardening as can be seen on an increase of the structurally sensitive remnant magnetization. The hard oxide inclusions evoke also the hardening of material, rise brittleness and crack liability.     

利用材料磁性检验盘条冷速与性能的一致性

研究了盘条的磁性、硬度与其在斯太尔摩线上冷速间的关系。发现强磁场下的饱和磁感应强度、剩磁、导磁率和硬度与冷速间不存在单调关系，而在弱场下的磁性与冷速间却是密切与单调性相关。证实，可以开发出一种准确、简单和迅速检测盘条性能和冷却一致性的方法。     

Low-temperature magnetic properties of amorphous metal alloys

The magnetic properties of amorphous metal alloys based on iron, silicon, and boron, with additions of other elements, are investigated at liquid-nitrogen temperatures. The magnetization and saturation magnetic field (magnetic hardness) of the alloy depend on the element added (carbon, phosphorus, or nickel). The maximum saturation magnetization is observed for the alloy with carbon, and the maximum saturation magnetic field for the alloy with phosphorus.     

新型稀土电极材料

介绍了添加稀土氧化物的新型电极材料钨镧、钨钇及随行料钨铈、钨锆的研制过程,并列出了其主要工艺参数和材料电性能测定结果。通过组织和性能分析认为:Y_2O_3对细化合金粉及烧结合金晶粒度的作用最明显,以W_4O_(11)为基添加氧化物比以WO_3为基的性能优良。并且通过电弧特性的比较得出,在研制的几种电极材料中,新型电极材料WLa_(15)性能最佳。     

Influence of Non—Magnetic Substitutional Atoms on Spontaneous Moment and Curie Temperature of Ce2Co17Compounds

The structure and magnetic properties of Ce2Co17-xMx(M=Ga,Al and Si)compounds for Mcomcentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements,The experimental results show that the Curie temperatures and Co spontaneous magnetization decrease significantly with increasing the addition of non-magnetic substitutional atoms,and that Si which has a minimum solid solubility ic Ce2Co17causes a largest reduction of Curie temperature,spontaneous magnetization and moment perCo atom compared with Ga and Al.     

烧结工艺对注射成形Fe-50%Ni软磁材料磁性能的影响

采用单质羰基铁粉和羰基镍粉,运用注射成形工艺制得了高性能的Fe-50％Ni软磁材料,系统地研究了烧结工艺中不同的烧结温度、烧结时间对材料的密度、磁性能的影响,同时对采用本工艺方法制得的Fe-50％Ni软磁材料的磁化曲线和磁滞回线进行了测试和分析。     

Effect of rare earth on physical properties of Na0.5Bi0.5TiO3 system: A density functional theory investigation

Na_0.5(Bi_3/4RE_1/4)_0.5TiO₃ (RENBT, RE = Nd, Gd, Dy, and Ho) compounds were investigated in the framework of first-principles calculations using the full potential linearized augmented plane wave (FP-LAPW) method based on the spin-polarized density functional theory implemented in the WIEN2k code. Combined charge density distribution and Ti K-edge X-ray absorption spectra reveal that the RENBT compositions with high polarization values are accompanied by a higher TiO₆ distortion, DyNBT, and NdNBT compounds. The effect of the rare-earth elements on the polarization is confirmed experimentally with the collection of the hysteresis loops. The investigation of the electronic properties of the compounds highlights the emergence of a magnetization owing to the 4f orbital effect of the rare-earth elements. Besides, the investigation of the chemical ordering shows a short-range chemical ordering for the pure composition and an increased A-site disorder for dysprosium doped NBT system. The increased disorder may speak for increased relaxor properties in the RE doped compositions.     

Sm2Fe17Nx稀土永磁材料的研究现状及进展

简要分析了Sm2Fe17Nx的晶体结构、内禀磁特性和N原子与磁性能的关系。着重介绍了Sm2Fe17Nx永磁材料的制备方法以及目前制备工艺存在的问题,并指出了其研究和发展趋势。     

Effect of mechanical activation of rare-earth metal oxides on the viscosity of borate melts

Effect of mechanical activation of yttrium-group rare-earth metal (REM) oxides on the viscosity of borate melts is studied. The concentration of Gd, Dy, Ho, and Lu oxides is found to affect the viscosity and solidification temperature of these melts.     

Magnetic properties of rare earth HoCrO_3 chromites

The temperature dependence of the magnetic properties was systemically studied by dc/ac magnetization and specific heat measurement for heavy rare earth HoCrO3 chromites.The results revealed the existence of complex phase coexistence and competitive magnetic behavior in HoCrO3 chromites.It was found that,in the region of higher temperature above 141.0 K,HoCrO3 behaved as a typical Curie-Weiss paramagnetic(PM).And in the region of low temperature,a novel magnetization behavior was observed with negative magnetization(diamagnetism-like) characteristics under an external field of 100 Oe and M-T curves exhibited two symmetrical branches for field cooling(FC) and zero field cooling(ZFC) modes.This behavior indicated the coexistence of canted antiferromagnetic(CAFM) and weak ferromagnetic(FM) phase.These also exhibited the existence of competition mechanism below characteristic temperature TN1=141.0 K and the magnetic order of Ho ion below 7.5 K.The current complex magnetization might be attributed to the interaction between paramagnetic Ho3+ moments and canted Cr3+ moments.     

Composite Ceramics for Thermal Barrier Coatings Produced From ZrO2 Doped with Yttrium-Subgroup Rare-Earth Metal Oxides

Powder Metallurgy and Metal Ceramics - The use of compositionally complex ZrO2-based ceramics doped with a mixture of yttrium-subgroup rare-earth metal (REM) oxides for the deposition of thermal...     

Influence of the Concentrate of Rare-Earth Elements on the Stabilization of High-Temperature Phases and Properties of the ZrO2–7Y2O3-Based Ceramics

Russian Journal of Non-Ferrous Metals - Powders based on the ZrO2–7 wt % Y2O3 system, into which oxides of rare-earth elements (REE)—La, Nd, and Pr—were introduced in the form of...     

Nb添加对Nd-Ce-Fe-B合金的磁性能及晶间交换耦合作用的影响

研究了不同含量的Nb添加对(Nd_0.5Ce_0.5)₁₃Fe_82-xNb_xB₅快淬合金的磁性能、物相组成、交换耦合作用及其初始磁化机制的影响.发现Nb添加能抑制α-Fe的形成,显著改善合金的磁性能.当Nb的添加量(原子分数)为0.5%时,合金获得较优的磁性能.随着Nb的添加量(原子分数)从0增加到0.5%,合金的矫顽力由未添加时的777 kA/m提升到900 kA/m, 最大磁能积也从未添加Nb时的64 kJ/m3增加到78 kJ/m3,而合金的剩磁仅由未添加Nb时的0.71 T轻微下降到0.70 T.合金中晶粒间的交换耦合作用随着Nb的添加而增强.合金的初始磁化机制也有了显著地变化.      

Behavior of leaching and precipitation of weathering crust ion-absorbed type by magnetic field

With weathering crust Ion-Absorbed Type Rare Earth （IATRE） ores in southern Jiangxi as an example, rare earth percolation leaching and leaching solution precipitation process research were carried out under conditions of magnetic field. The effect on the rare earth leaching process such as magnetic field strength, magnetization time, magnetization manner, and other factors were discussed. The effect on the mother rare earth liquor sedimentation rate, purity, and crystallization behavior such as magnetic field strength, magnetization time, and magnetization manner were investigated. Leaching and precipitation mechanism of magnetization on IATRE were analyzed. The results showed that the magnetic treatment can improve leaching rate of weathering crust IATRE and the sedimentation rate, and reduce consumption of reagents.