共查询到19条相似文献,搜索用时 109 毫秒
1.
Moessbauer谱学及其在熔渣铁离子行为研究中的应用 总被引:123,自引:0,他引:123
综述了Moessbauer谱学原理、基本参数和测定方法;分析了熔渣中铁离子行为,并从化学和谱学角度阐述了Fe^2 和Feoct^3 离子的Moessbauer谱特征,讨论了铁离子行为与熔渣碱度、渣中全铁量及Na2O、Al2O3含量的关系;提出该领域的研究前景。 相似文献
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本文通过对 [Fe3 O(Ala) 6(H2 O) 3 ](Cl O4) 7和 [Fe3 O(Gly) 6(H2 O) 3 ](NO3 ) 7· 3H2 O的 ESR谱的解析及变温磁化率的研究 ,得出它们的 ESR谱具有各向同性的特点 ;朗德因子分别为 2 .0 19和 1.997;两种配合物中铁离子间有反铁磁相互作用 相似文献
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本文通过对[Fe 3O(Ala) 6(H 2O) 3](ClO 4) 7和[Fe 3O(Gly) 6(H 2O) 3](NO 3) 7·3H 2O的ESR谱的解析及变温磁化率的研究,得出它们的ESR谱具有各向同性的特点;朗德因子分别为2.019和1.997;两种配合物中铁离子间有反铁磁相互作用. 相似文献
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Al2O3:Fe3+体系晶格局域结构的EPR理论研究 总被引:3,自引:1,他引:2
本文通过分析Al2O3∶Fe3+体系中Fe3+离子的EPR谱,研究Fe3+的局域晶体结构结果表明Al2O3∶Fe3+的局域结构存在各向异性膨胀.用拟合EPR谱的低对称参量D和(a-F)实验值的方法,求得两个三棱锥的棱与C3轴的夹角分别为θ1=46.54°和θ2=61.26°,相对于原Al2O3结构的畸变角分别是Δθ1=-1.1°±0.1°,Δθ2=-1.8°.两畸变角同时均小于0说明Al2O3∶Fe3+体系中含Fe3+离子的晶格主要产生沿C3轴的伸长畸变. 相似文献
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本文通过分析Al2 O3 ∶Fe3 + 体系中Fe3 + 离子的EPR谱 ,研究Fe3 + 的局域晶体结构结果表明Al2 O3 ∶Fe3 + 的局域结构存在各向异性膨胀。用拟合EPR谱的低对称参量D和 (a -F)实验值的方法 ,求得两个三棱锥的棱与C3 轴的夹角分别为θ1=4 6 .5 4°和θ2 =6 1.2 6° ,相对于原Al2 O3 结构的畸变角分别是Δθ1=- 1.1°± 0 .1° ,Δθ2 =- 1.8°。两畸变角同时均小于 0说明Al2 O3 ∶Fe3 + 体系中含Fe3 + 离子的晶格主要产生沿C3 轴的伸长畸变 相似文献
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合成和表征了两种新的Schiff碱配合物[NiL(ClO4)*3H2O (1)和CuL(ClO4)*4H2O (2),其中L是由摩尔比为1∶1的水杨醛和二乙撑三胺缩合而成的Schiff碱.1(或2)、FeSO4*7H2O和K3[Fe(ox)3]*3H2O进一步反应,生成了双金属层状配位聚合物{[ML][FeⅡFeⅢ(ox)3] *1.5 H2O}∞,其中M2+ = Ni2+ (3)或Cu2+ (4).红外光谱和Mssbauer谱测定结果表明,3和4具有二维层状结构,其阴离子层由[FeⅡFeⅢ(ox)3]-单元构成. 相似文献
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Vibrations and chemical states of iron ions in soda‐lime glasses determined by element‐specific X‐ray analyses 下载免费PDF全文
Kyoko Okada Yukihito Nagashima Koichi Shiraki Hiroki Kageyama Hironori Ofuchi Yoshitaka Yoda Yasuhiro Kobayashi Norimasa Umesaki Yoshiharu Sakurai 《X射线光谱测定》2018,47(5):359-371
We systematically study medium‐range structures including more than three neighboring atoms around iron ions (Fe2+ and Fe3+) in soda‐lime glass samples with low iron oxide concentrations (MFe2O3) and a wide number ratio of Fe2+ to all iron ions (Fe2+/ΣnFe). The precise medium‐range structures around iron ions in glass have not yet been revealed because of a lack of the appropriate measurement methods. To avoid this problem, we used element‐specific nuclear resonant inelastic scattering (NRIS) with synchrotron X‐rays to observe the vibrations of iron ions (57Fe). The vibrations are related to medium‐range structures with more than three neighboring atoms and to the potential asymmetry and the coordination environment, around iron ions. The NRIS method has high sensitivity and can measure over a wide concentration range. Linear combination fitting of the X‐ray absorption fine structure spectra, which measures only the first neighbors but is a faster than using the NRIS method, was also used additionally. A systematically produced set of glasses with 0.015–5 wt% MFe2O3 and 0–0.85 Fe2+/ΣnFe was measured with these methods. It was found that the soda‐lime glass possessed two different medium‐range structures with different iron ion valences (~2+ or ~3+), which were determined by the Fe2+/ΣnFe, and that these structures were generated during production of the glass. Moreover, these medium‐range structures were the same from 0.015 to 5 wt% MFe2O3. 相似文献
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Optics and Spectroscopy - The change in the vibration spectrum of an iron [Fe(OH)2(H2O)2]+ hydroxo cation during its interaction with peroxynitrite [NO–O2]? in an aqueous medium... 相似文献
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F.E. Spada F.T. Parker C.Y. Nakakura A.E. Berkowitz 《Journal of magnetism and magnetic materials》1993,120(1-3):129-135
The coercive force of small, acicular ( 2000 Å length, 8:1 length-to-diameter ratio) spinel-type iron oxide particles increases substantially following surface treatment with sodium polyphosphate. Regardless of Fe2+/Fe3+ cation ratio, Hc always attains a peak value when the polyphosphate/iron oxide weight ratio P/Fe is in the range 0.5–0.6, denoted (P/Fe)max. The maximum change in Hc is observed when Fe2+/Fe3+ ≈ 0.10–0.15. When P/Fe0.5–0.6, however, both magnitude and sign of the change in coercive force show strong dependence on the Fe2+ content of the oxide, suggesting that the Hc changes are caused by a magnetostrictive mechanism at these high treatment ratios. Calculated anisotropy field distributions of treated specimens show that both the mean anisotropy field δHkδG and predicted Hc reach a peak when particles are treated at (P/Fe)max, where the distribution becomes very broad. At high treatment ratios both δHkδG and predicted Hc decrease to values below that of the untreated oxide. Mössbauer studies of treated and untreated particles show no significant change in the environment of surface iron ions following treatement at P/FE = 0.5, but indicate a small increase in the Fe3+ concentration of the particle core. When P/Fe = 2.5, however, the Fe2+ concentration of the core increases markedly. 相似文献
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Zhi Yu Yuan Zhou Xin Jin Qingyou Lu Runsheng Huang Rongchuan Liu Yuanfu Hsia 《Hyperfine Interactions》1990,55(1-4):1411-1415
Various phenomena induced by iron cation substitution for copper in high-T
c superconductor are discussed. Fe cations are substituted for both Cu(1) and Cu(2) sites, but the substitution is preferentially
taking place on Cu(1) chain sites atx<3%. The Fe cations at Cu(1) chain sites exhibit anisotropic vibration. Three different types of oxygen coordinations of Fe(1)
cations are identified by the point-charge model. The calculation indicates that Fe3+ are present in tetrahedral, pyramidal, and distorted octahedral coordinations. 相似文献
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用H2及CO还原氧化铁过程中,使用了X-ray粉末衍射和化学分析方法确定了氧化铁及金属铁的定量分析关系.铁素体(αFe)、奥氏体(γFe)、碳化铁(Fe3C)、磁铁矿(Fe3O4)、赤铁矿(Fe2O3)与浮氏体(Fe0.947O)的摩尔强度定量关系的系数分别为0.56,0.56,0.52,0.87和2.57.通过这些系数,可以计算出氧化铁的金属化率和还原率. 相似文献
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The diffusion of 59Fe and 60Co has been measured in pure CoO and dilute iron-doped CoO, (Co1?cFecO, as a function of temperature (1000–1400°C) and oxygen partial pressure Po2), (10?7 ≦ Po2 ≦ 0 21 atm) The enhancement factors for the diffusivities of iron and cobalt are nearly identical, which suggests that the primary cause of the enhancement is the increased concentration of charge-compensating cation vacancies with the addition of iron. The Fe ions dissolved in CoO appear to exist as a mixture of Fe2+ and Fe3+ ions, the fraction of iron ions in the three-plus state decreases with decreasing Po2 The simultaneous diffusion of 52Fe and 59Fe has been measured as a function of (itpo; at 1200°C The correlation factor for Fe impurity diffusion determined from the isotope-effect measurements is about the same as that for self-diffusion in CoO at high (itPo2 (2 × 10?3 ≦ po2 ≦ 0 21 atm), but increases slightly with decreasing pO2 Both the enhancement-effect and isotope-effect experiments suggest that the nearestneighbor interactions between Fe ions and vacancies is small, and that the dissolved Fe ions do not have strongly bound electron holes. 相似文献
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Maria C. Blanco Diego G. Franco Yamile Jalit Elisa V. Pannunzio Miner Graciele Berndt Andrea Paesano Jr. Gladys Nieva Raúl E. Carbonio 《Physica B: Condensed Matter》2012,407(16):3078-3080
The samples Bi2BB′O7, with B=Cr and Fe and B′=Nb, Ta and Sb were prepared by solid state method. The crystallographic structure was investigated on the basis of X-ray powder diffraction data. Rietveld refinements show that the crystal structure is cubic, space group Fd-3m. The Bi3+ cation on the eight-coordinate pyrochlore A-site shows displacive disorder, as a consequence of its lone pair electron con?guration. There is also a considerable A-site disorder shown by Rietveld Analysis and confirmed in the case of the iron containing samples with Mössbauer spectroscopy. The magnetic measurements show paramagnetic behavior at all temperatures for the Cr oxides. The Fe pyrochlores show antiferromagnetic order around 10 K. 相似文献
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A. Nakanishi 《Hyperfine Interactions》2008,186(1-3):135-139
For an investigation of the ancient iron manufacturing technique, a reproducing experiment was carried out by archaeologists, where ancient type of iron smelting furnace was built and iron sand with high titanium contents was used as the raw material. During the operation of furnace, a large amount of slag flowed away from the furnace. In order to investigate the possibility for the estimation about the operative condition of furnace and the raw material, 57Fe Mössbauer spectroscopy was applied for characterizing these slags and it was found that these slags mainly consisted of ferropseudobrookite (FeTi2O5). 相似文献