Applied Physics Letters
The effect of nonmagnetic Y partial substitution at the Dy site in Dy(1-x)Y(x)MnO(3) up to x=0.2 on magnetism, specific heat, and ferroelectricity is investigated, which resulted in a preliminary multiferroic phase diagram. It is revealed that the Y partial substitution suppresses the Dy-spin ordering point (T(Dy)) and ferroelectric ordering point (T(FE)) but enhances the Mn-spin ordering point (T(N)). The interaction between the spins of Dy and Mn is remarkably affected by Y substitution. The measured electrical polarization depends on the Y substitution in a complex way because the ferroelectricity is sensitive to the interaction between the spins of Dy and Mn. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3536506]
关键词:
ferroelectricity;polarization
史伟
,
王天新
,
王顺花
,
石宗利
兵器材料科学与工程
doi:10.3969/j.issn.1004-244X.2009.05.017
通过金相分析、扫描电镜等测试手段,对含有1%稀土Y元素的AM50和AZ91镁合金的微观组织和腐蚀性能进行研究,结合镁合金的腐蚀形貌,分析对比两种镁合金在相同腐蚀条件下的腐蚀机理.结果表明,由于两种镁合金成分上的差异,使得AM50-1Y较AZ91-1Y在实验室所采取的腐蚀条件下具有不同的耐腐蚀性能.
关键词:
AM50镁合金
,
AZ91镁合金
,
稀土Y
,
腐蚀
王桂英
,
唐永刚
,
毛强
,
郭腾
,
刘宁
,
彭振生
稀有金属
doi:10.13373/j.cnki.cjrm.2014.03.007
用固相反应法制备了Y1-xDyxCrO3(z =0,0.1)多晶样品.通过X射线衍射(XRD)图谱检测了样品的结构,测量了样品的磁性,作了磁化强度-温度(M-T)曲线、磁化强度-磁场(M-H)曲线,研究了Dy3替代Y3+对Y1-xDyxCrO3体系磁性质的影响.结果表明,Dy3替代多铁性YCrO3中的Y3+对YCrO3的磁性有效大影响.YCrO3在奈尔温度TN=139 K以下呈倾角反铁磁,显示弱铁磁性;Dy3+替代y3+后的Y0.gDy0.1CrO3样品,在50 K＜T＜142K温区,少量Dy3+在两相邻Cr3+产生的倾角反铁磁内场作用下沿内场反方向排列,使铁磁性减弱;在T＜50 K温区,Dy3+-O2--Dy3+层的铁磁性与Cr3+-O2--Cr3+层的铁磁性耦合,铁磁性增强.
关键词:
多铁性材料
,
Dy替代
,
磁性质
李果
,
沈腾明
,
赵勇
低温物理学报
doi:10.3969/j.issn.1000-3258.2005.z1.004
利用固相反应法制备了分别掺杂Sr和Ce的PrLaCuOz系列氧化物.XRD衍射结果表明,Sr的掺杂形成了典型的空穴型掺杂的T-214结构,Ce的引入形成了典型的电子型掺杂的T′-214结构.利用Quantum Design PPMS-VSM对所有样品的进行了M-T测量(5～300K;100高斯和5000高斯).临界温度随掺杂量变化的关系表明,当0.08≤x≤0.30时,PrLa1-xSrxCuOz(PLSCO)具有超导电性,并在x=0.15时达到最高值Tcmax=26K;当0.08≤y≤0.15时,Pr1-y LaCeyCuOz (PLCCO)具有超导电性,Tcmax=24.9K出现在y=0.12处.磁性质测量还表明,Sr的引入对体系的磁矩影响不大,而Ce的掺入使样品在35K附近出现了反铁磁转变.
关键词:
掺杂
,
电子型
,
空穴型
,
载流子`
Chinese Physics Letters
Magnetic properties of spin-ladder compounds Sr(14)(Cu(1-y)Fe(y))(24)O(41) (0 <= y <= 0.05) are investigated in the temperature range from 10 to 300 K. The result reveals that all the samples exhibit magnetic crossover behavior in the paramagnetic range, and Fe(3+) doping can efficiently increase the susceptibility due to the large moment of Fe(3+). Both the observations are consistent with our previous investigation on transport behaviors, indicating the strong correlation between the magnetism and transport behaviors. The spin gap is evidenced in all the samples, and strengthens as Fe(3+) doping level increases, which can be associated with the antiferromagnetic interaction between Fe(3+) and Cu cations.
关键词:
metal-insulator-transition;material sr14cu24o41;cuo2 chains;superconductivity;dynamics;state;gap;nmr;sr14-xcaxcu24o41;interplay
Ieee Transactions on Magnetics
The spin orientation and spontaneous magnetostriction of multicomponent TbxDy1-x-yPry(Fe0.9B0.1)(1.93) (0.10 less than or equal to x less than or equal to 0.25, 0.30 less than or equal to y less than or equal to 0.60) Laves phases were studied by step-scanning their (440) X-ray diffraction lines. The easy magnetization direction (EMD) of the Laves phases changed from the (100) to (111) axis when x was increased from 0.10 to 0.25. With increasing y, the EMD of Tb0.15Dy0.85-yPry(Fe0.9B0.1)(1.93) and Tb0.2Dy0.8-yPry(Fe0.9B0.1)(1.93) Laves phases reoriented from the (100) to (111) axis. The magnetostriction coefficient lambda(111) of TbxDy1-x-yPry(Fe0.9B0.1)(1.93) Laves phases increased with increasing x (or y) when y (or x) was kept constant.
关键词:
Laves phases;magnetostriction;spin orientation;X-ray diffraction;anisotropy compensation;alloys
Journal of Alloys and Compounds
(Ca(1-x-y),Ln(y))MoO(4): xEu(3+) (Ln = Y, Gd) red phosphors were prepared by co-precipitation method with NH(4)HCO(3)-NH(3)center dot H(2)O system as the precipitating agent. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR), and energy-dispersive X-ray spectrometer (EDS) were used to characterize the structure and composition of the phosphors. The synthesized (Ca(1-x-y),Ln(y))MoO(4): xEu(3+) have scheelite structure with pure phase. FT-IR spectra show strong absorption peaks between 914 and 730 cm(-1) which are assigned to the vibration of O-Mo-O in MoO(4)(2-) tetrahedron. The EDS analysis reveals that the red phosphors have been successfully prepared by co-precipitation method according to theoretic ratio. Photoluminescence spectra show a red emission around 614 with 394 and 464 nm excitation, which is match well with the output wavelength of commercial ultraviolet and blue LED chips. The luminescent intensity of (Ca,Ln)MoO(4): Eu(3+) is obviously higher than that of CaMoO(4): xEu(3+). Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
关键词:
Co-precipitation;Red phosphor;Photoluminescence;(Ca(1-x-y),Ln(y))MoO(4): xEu(3+) (Ln = Y Gd);hydrothermal synthesis;camoo4;eu3+;luminescence
李国华
,
马淳安
,
郑遗凡
,
徐铸德
无机材料学报
无机类富勒烯纳米粒子具有良好的润滑性能. 宏量制备高纯度的样品以满足性能测试的要求, 是目前面临的主要技术难题. 本文采用剥离-掺杂-水热处理这一工艺流程制备了多元金
属二硫化物纳米粒子, 应用XRD、TEM、HRTEM和EDS等分析手段对其形貌、晶相组成、结构和化学组成进行了表征. 实验结果表明, 多元金属二硫化物纳米颗粒具有管状形貌,管壁为
多层状结构, 化学组成为NiX(WYMo1-Y)1-XS2, 同时, 样品中具有类富勒烯结构的纳米粒子大幅度提高; 并依据实验结果对多元金属二硫化物纳米管的形成机理进行了探讨.
关键词:
剥离-掺杂-水热处理
,
multi-metal disulfide
方西亚
,
易丹青
,
王斌
,
罗文海
,
顾威
稀有金属
doi:10.3969/j.issn.0258-7076.2006.06.002
在Mg-6Al-1Zn合金的基础上添加不同质量分数的Y(分别为0%,0.5%,0.9%,1.4%),制备了4种实验合金,研究了Y的添加对合金组织性能的影响.通过X射线衍射、金相显微镜、扫描电镜、电子探针等手段分析了Mg-6Al-1Zn合金添加Y后组织结构的变化.研究结果表明,添加了不同含量Y的合金中都出现了一种新相Al2Y相.随着Y含量的增加,Al2Y相数量增多而Mg17Al12相则减少.Y能细化合金铸态及挤压态显微组织,其细化作用在添加了0.9%Y的镁合金中尤为明显.铸态合金室温拉伸试验表明:该合金具有最佳的综合力学性能.当Y含量添加至1.4%时,Al2Y相变得粗大且出现团聚现象而导致了拉伸性能的下降.经过挤压后,合金的力学性能大幅度上升.
关键词:
Mg-6Al-1Zn-Y合金
,
显微组织
,
力学性能
