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1.
用测量固体电解质电池电动势(EMF)的方法,测试了Sm-Ba-Cu-O体系主要化合物的标准Gibbs生成自由能;结果发现,稀土复合氧化物Sm_(1+x)Ba_(2-x)Cu_3O_y,随着固溶度x增加,化合物稳定性下降DTA实验支持这一结论。  相似文献   

2.
用Ga取代部分Fe对R3(Fe,Mo)29结构及磁性的影响   总被引:1,自引:1,他引:0  
详细研究了Ga取代R3(Fe,Mo)29(R=Sm,Y)(Ga<0.15)中的部分Fe对其结构和内禀磁性的影响,包括不同的Ga取代对R3(Fe,Mo)29化合物的晶胞常数、居里温度、饱和磁化强度、磁晶各向异性的影响。结果表明:在R3(Fe,Mo,Ga)29化合物中,随着Ga含量的增加,晶胞体积膨胀,居里温度升高,饱和磁化强度下降,Fe原子的平均磁矩降低,Sm3(Fe0.966-xMo0.034Gax)29化合物的各向异性由平面向锥面结构转变,继续增加Ga含量,有可能出现单轴各向异性。  相似文献   

3.
采用真空单辊快淬法(铜辊,线速度达20~23m/s)将成分为(Sm1-xBx)Fe2(x=0,0.015,0.03,0.045,0.06)合金锭,制成快速凝固的鳞片状合金,再经粉碎在30MPa压力下,模压成φ10mm圆片,然后进行XRD分析,比磁化强度和磁致伸缩(λ″-λ┴)的测量。实验结果表明各样品只有少量非晶相,主要是SmFe2及少量的SmFe5和SmFe7化合物。样品(Sm0.985B0.015)Fe2和(Sm0.94B0.06)Fe2,在720kA/m磁场下,比磁化强度分别为:59.5,52.3Am2kg-1,在885kA/m磁场下(λ″-λ┴)分别为:-510×10-6和-310×10-6。  相似文献   

4.
R3(Fe,Mo)29(R=Sm,Y)化合物及其氮化物的磁性   总被引:2,自引:0,他引:2  
合成了R3(Fe,Mo)29(R=Sm,Y)化合物并在0.1MPa氮气条件下通过气相氮化法制备出其氮化物。R3(Fe,Mo)29金属间化合物氮化后仍保持母相结构,但是晶胞体积发生膨胀,氮化处理同时导致化合物居里温度Tc和饱和磁化强度σs升高同时Sm3(Fe,Mo)29化合物由平面各向异性变为单轴各向异性,但Y3(Fe,Mo)29Nx化合物的各向异性仍与母相相同,为面各向异性。  相似文献   

5.
通过Mossbauer谱等研究(Sm1-xYx)2Fe17Ny的磁性。结果表明:Sm次格子的单轴各向异性较强,对总的各向异性贡献起主导机制;Y原子的择优占位导致晶体结构的变化,而对各向异性的影响较小。  相似文献   

6.
研究了氮原子在Sm_2Fe_(17)合金中的扩散行为,测定了扩散温度、时间与样品平均氮含量的关系,以及氮原子在样品中的分布;计算了氮原子在Sm_2Fe_(17)合金中的扩散频率因子D_0和扩散激活能Q,运用扩散Fick第二定律计算了氮原子在Sm_2Fe_(17)粉末颗粒内部的分布及其与扩散温度、扩散时间、颗粒尺寸之间的关系.理论计算与实验结果一致.  相似文献   

7.
MathematicalSimulationofNdandSmExtractSeparationin(Nd,Sm)Cl_3-HCL-HEHEHP-KeroseneSystemHuangWenmei;YingWeijuanandWangNaibin(黄...  相似文献   

8.
BINDINGENERGYOFTHESHALLOWDONORIN(CdTe)_m/(ZnTe)_nSTRAINEDDOUBLEQUANTUMWELL¥XINGJinhai(DepartmentofPhysics,LiaoningUniversity,S...  相似文献   

9.
用XRD法研究了退火Fe73.5Cu1Mo3Si14.5B8合金中α-Fe(Si)晶化相的有序化过程,结果表明,Fe73.5Cu1Mo3Si14.5B8非晶合金经460℃×1h退火后,α-Fe(Si)晶化相是具有DO3结构的有序相,有序畴为球形,直径为6.1nm,它随退火温度的升高而长大,在560℃退火后达14.0nm,与α-Fe(Si)晶粒的尺寸相当。此时,α-Fe(Si)的有序度为0.78。800℃×1h退火后,α-Fe(Si)的DO8超点阵线条消失。  相似文献   

10.
铝液与SiO2反应原位形成Al/Al2O3(P)复合材料的研究   总被引:7,自引:1,他引:7  
将铸造方法与原位技术相结合研制出原位形成的Al/Al2O3(P)复合材料。向铝液中添加(搅入法)预先在300℃下烘烤3h、粒径为300μm的SiO2颗粒,发生如下反应:3SiO2+4Al=3Si+2Al2O3,其结果,原位形成颗粒分布均匀的Al/Al2O3(P)复合材料  相似文献   

11.
The structure, magnetization, and magnetocrystalline anisotropy were investigated using X-ray diffraction, vibrating sample magnetometer, and AC susceptibility-meter. It is found that the microstructure of (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys is an (Sm,Nd)2(Fe,Co)17 phase with the rhombohedral Th2Zn17-type structure. The Curie temperature Tc increases with the Co concentration increasing, and the magnetization first increases as the Co content increases in (Sm0.5Nd0.5)2(Fe1-xCox)17 alloys and then decreases slowly. The easy magnetization direction (EMD) of (Sm0.5Nd0.5)2(Fe0.25Co0.75)17 is along the c-axis and a strong enhancement of the crystalline anisotropy energy constant K is produced by the addition of some Co atoms. The anisotropy energy constant reaches the maximum when x = 0.75 and then decreases slowly with the Co content further increasing. The (Sm0.5Nd0.5)2(Fe0.25Co0.75)17compound is an optical candidate for the new permanent magnet, which possesses a high magnetization, a high Curie temperature,  相似文献   

12.
INTRODUCTIONTheR3(Fe,M)29(R=rareearth;M=Ti,V,Mn,Mo,etc)compoundsarenewlydiscoveredrareearthironintermetalics.Theyalmostexist...  相似文献   

13.
钛在自贡鸿鹤化工总厂联碱生产中的应用   总被引:7,自引:1,他引:7  
简述了Sm2Fe(17)Nx化合物的结构与内禀磁性能,着重回顾了Sm2Fe(17)Nx永磁合金粉及其磁体的制备工艺发展现状,并展望了Sm2Fe(17)Nx永磁体的发展前景。  相似文献   

14.
The thermal expansion along the longitudinal and transverse directions for amorphousFe_(78)B_(13)Si_9 alloy prepared under various preparing conditions were investigated.The thermalexpansion anisotropy appears in all specimens.The expansion along the longitudinal directionis less than that along the transverse direction.The cooling rate,the melt temperature beforejet casting and the cycling temperature affect the thermal expansion coefficients andanisotropy.The amisotropy of thermal expansion originates from the orientation of atomicinteraction force,the atomic oscillatory frequency and short range order structure or thedirectional arrangement of defects in the alloy.  相似文献   

15.
The novel ternary rare-earth iron-rich interstitial compounds R3(Fe,Cr)29Xy (R=Nd, Sm and X=N, C) with the monoclinic Nd3(Fe,Ti)29 structure have been successfully synthesized. Introduction of the interstitial nitrogen and carbon atoms led to a relative volume expansion ΔV/V of about 6% and an enhancement of Curie temperatures Tc about 268 K for the nitride and about 139 K for the carbide, respectively. The Nd3Fe24.5Cr4.5Xy compounds have a planar anisotropy at room temperature. A first-order magnetization process (FOMP) with critical field Bcr=4.4 T and 3.1 T at room temperature were observed for the Nd-nitride and carbide compounds, respectively. The Sm3Fe24Cr5Xy compounds were found to have a large uniaxial anisotropy of about 18 T at 4.2 K and about 11 T at 293 K. A FOMP with Bcr=2.3 T was also observed in the Sm-nitride compounds at 4.2 K. Magnets with coercivity of μOjHc0.8 T at 293 K has been successfully developed from the Sm3Fe24Cr5Xy (X---N and C) phases.  相似文献   

16.
陆坚  王景唐  丁炳哲 《金属学报》1989,25(3):102-106
本文研究了不同条件下形成的非易态Fe_(78)B_(13)Si_9合金在长轴和短轴方向上的热膨胀。结果表明,在所有条件下均存在热膨胀的各向异性。热膨胀系数随着冷却速度的增加而增加,但其各向异性减小;随着熔体喷铸温度的提高两者均减小。在热循环的作用下,短轴方向的热膨胀系数及其各向异性均减小;而在长轴方向的热膨胀系数却增大。我们认为热膨胀各向异性来源于原子交互作用力的方向性、原子振动频率和短程有序结构或缺陷的方向性。  相似文献   

17.
采用熔体快淬方法制备了不同辊速(v=12m/s、15m/s、20m/s)条件下的Fe_(85)Ga_(15)合金薄带样品,对薄带样品的组织结构和磁致伸缩性能进行了研究.结果表明,合金薄带的组织结构和磁致伸缩性能与快淬时的冷却速度密切相关,v=20m/s辊速条件下制备的薄带在磁场为45kA/m时,其磁致伸缩系数λ达-125×10~6,伸缩曲线尚未完全饱和.对薄带组织形貌的观察表明,薄带样品内晶粒沿薄带厚度方向呈现出取向性排列.XRD分析表明,辊速的提高可以抑制有序DO_3相的析出,α-Fe相和非对称DO_3结构的Fe_3Ga相衍射峰发生重叠并有劈裂现象.TEM分析表明,合金基体中存在着富Ga原子团簇.薄带样品大的磁致伸缩系数主要来源于样品强的形状各向异性和非平衡制备条件下合金内部的特殊晶体结构.  相似文献   

18.
《Intermetallics》2005,13(7):710-716
The crystal structure and magnetic properties of Sm(Co,M)7 (M=Si, Cu, Ti, Zr, and Hf) compounds with the TbCu7-type structure have been investigated by means of X-ray powder diffraction and magnetic measurements. For the Sm(Co,M)7 compounds, the formation of the compound is dominated by the enthalpy of formation of MCo7, atomic radius ratio of Sm to (Co, M) and the electronic configuration of the doping element M, while the site occupation of M is determined by the enthalpies of solution of M in liquid Sm and Co as well as by the electronegativity difference among M, Sm and Co. However, the Sm(Co,Cu)7 compounds exhibit different stabilizing mechanism, which may be due to the large mutual solubility between Co and Cu in the Sm(Co,Cu)7. The stabilizing element Si and Cu prefer to occupy the 3g site, whereas Ti, Zr and Hf have preference to occupy the 2e site. Both the saturation magnetization and Curie temperature of the Sm(Co,M)7 compounds decrease with increasing M content, while the magnetic anisotropy increases with increasing M content. The magnetic anisotropy field is related closely to the content and site occupation of the doping element M, which agrees with the theoretical analysis based on the individual site contribution model.  相似文献   

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