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1.
Binding energy shifts between atomic and solid phases for transition metals Cr, Mn, Fe, Co, and Ni have been obtained for 3p subshells from simultaneously recorded atomic vapor and solid state spectra. This experimental technique provides higher accuracy in comparison to separate measurements and allows direct determination of the shifts. The observed shift values are compared to values obtained using the semiempirical Born–Haber cycle method and the peak structures of the solid state photoelectron spectra are compared to atomic 3p spectra. The binding energy shift of Cr is found to be much smaller than that of the other studied elements.  相似文献   

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Calculations of the band structure of the ferromagnetic alloys Ni3Mn, Ni3Fe, and Ni3Co are presented. The results are compared with experimental data. Change in the electronic structure as one goes from Ni3Mn to Ni3Co is analyzed. The occurrence of ferromagnetism in the alloys studied and the possibility of their existence in an ordered ferromagnetic state are examined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 82–88, June, 1988.  相似文献   

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K shell X-ray production cross-sections in the Ti, V, Cr, Mn, Fe, Co, Ni, and Cu in the molecules were studied at 59.5 keV excitation energy by using a Si(Li) detector ( FWHM = 155 eV at 5.96 keV). The present results are compared with other theoretical values.  相似文献   

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Physics of the Solid State - The linear thermal expansion coefficients (LTEC) of semimetallic Fe2MAl (M = Ti, V, Cr, Mn, Fe, Co, and Ni) alloys have been measured in the temperature range...  相似文献   

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An experimental study was made of the changes in the normal and anomalous Hall constants R0 and Rs, respectively, the internal saturation induction Bs, and the resistivity ? during the ordering of quasibinary Ni3Mn-Ni3Fe and Ni3Mn-Ni3Co alloys. The concentration dependences of R0, Rs, Bs, and ? were also studied in the ordered state of these alloys. It is concluded from an analysis of the experimental results that the decreases inR0 and ? during the ordering of Ni3Mn and as a result of the alloying of ordered Ni3Mn with slight amounts (~5 at. %) of iron are due primarily to a decrease in the hole contribution to transport and to a decrease in the state density in the 3d band of these alloys near the Fermi level. The experimental data are in satisfactory agreement with the curve calculated by Yamashita et al. [6] for the density of 3d states in ordered Ni3Mn and Ni3Fe alloys.  相似文献   

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The normal and anomalous Hall constants R0 and Rs, respectively, and the resistivity have been measured for the quasibinary alloys Ni3Mn-Ni3Fe and Ni3Mn-Ni3Co. The results imply that in ternary alloys of Ni3Mn containing slight Fe and Co impurities the hole regions of the Fermi surface make an important contribution to R0 and that the primary scattering mechanism for the carriers corresponding to the anomalous Hall current in the alloys with Fe at room temperature is phonon scattering. It is concluded that the Fermi surface of the Ni3Mn-Ni3Fe alloys is closed.Translated from Izvestiya VUZ. Fizika, No. 3, pp. 21–29, March, 1970.  相似文献   

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The effects of transition metals (Cr, Mn, Fe, Co and Ni) on the catalytic properties of Pd/Ce-Zr/Al2O3 catalyst for methane combustion have been investigated. The supported Pd catalysts are characterized by BET, XRD, TEM, TPR, TPO and TPSR measurements. Activity tests in methane combustion show that Pd/Ce-Zr-Ni/Al2O3 has the highest catalytic activity and thermal stability among all catalysts. The results of TEM show that the addition of Ni to Pd/Ce-Zr/Al2O3 increases the dispersion of Pd component and inhibits the site growth. The results of TPO and TPSR show that the addition of Ni inhibits the decomposition of PdO particles and improves the reduction-reoxidation properties of the active PdO species, which increases the catalytic activity and thermal stability of the Pd/Ce-Zr/Al2O3 catalyst.  相似文献   

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骆最芬  陈星源  林诗源  赵宇军 《物理学报》2013,62(5):53102-053102
本文采用基于密度泛函理论的广义梯度近似方法和赝势平面波法的第一性原理计算及化学势的热力学平衡原理,对BiXO3 (X= Cr, Mn, Fe, Ni)的结构稳定性进行了仔细的研究. 结果表明,这四种多铁化合物中, BiFeO3最稳定, BiCrO3次之, 而BiMnO3和BiNiO3则很难在热平衡条件下稳定,因此在样品制备中要多考虑热平衡之外的手段. 关键词: 3')" href="#">BiXO3 结构稳定性 第一性原理  相似文献   

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The dependence of the coercive field and saturated magnetization on the interfacial width is studied to understand the driving mechanism of the coercive enhancement in Fe/Mn and Co/Mn bilayers. We establish a controlled annealing procedure to reveal the origin of this enhancement. Using a model, we reveal that the full interfacial width plays a keyrole, and that no Mn based finite size effects drive the mechanism. We show that this mechanism is common to both type of bilayers.  相似文献   

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Physics of the Solid State - The thermal expansion coefficient (TEC) of Co2MAl (M = Ti, V, Cr, Mn, Fe, Ni) band ferromagnets is measured in the temperature interval of 80–900 K. The...  相似文献   

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We report and discuss experimental data on the thermoelectric power of magnetic multilayers. Measurements of the thermoelectric power of Fe/Cr, Co/Cu and Fe/Cu multilayers have been carried out in the temperature range 4K < T < 150 K magnetic fields perpendicular to the layers. All specimens were found to exhibit pronounced magnetothermoelectric power (MTEP) effects correlating with their giant negative magnetoresistance. The main difference between the MTEP and the magnetoresistance is in their temperature dependence. Whereas the magnetoresistance is a decreasing function of temperature, the MTEP, at least in Co/Cu and Fe/Cu multilayers, is very small at low temperature and increases rapidly above 30–40 K. We ascribe this high temperature part of the MTEP to spin-dependent electron-magnon scattering and we propose a theoretical model.  相似文献   

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Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of their 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. Our previous paper [M.C. Biesinger et al., Appl. Surf. Sci. 257 (2010) 887-898.] in which we examined Sc, Ti, V, Cu and Zn species, has shown that all the values of the spectral fitting parameters for each specific species, i.e. binding energy (eV), full wide at half maximum (FWHM) value (eV) for each pass energy, spin-orbit splitting values and asymmetric peak shape fitting parameters, are not all normally provided in the literature and data bases, and are necessary for reproducible, quantitative chemical state analysis. A more consistent, practical and effective approach to curve fitting was developed based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of literature references and (3) specific literature references where fitting procedures are available. This paper extends this approach to the chemical states of Cr, Mn, Fe, Co and Ni metals, and various oxides and hydroxides where intense, complex multiplet splitting in many of the chemical states of these elements poses unique difficulties for chemical state analysis. The curve fitting procedures proposed use the same criteria as proposed previously but with the additional complexity of fitting of multiplet split spectra which has been done based on spectra of numerous reference materials and theoretical XPS modeling of these transition metal species. Binding energies, FWHM values, asymmetric peak shape fitting parameters, multiplet peak separation and peak area percentages are presented. The procedures developed can be utilized to remove uncertainties in the analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.  相似文献   

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便携式全反射X荧光同时测定清洁水体中多种元素   总被引:1,自引:0,他引:1  
应用便携式全反射X射线荧光分析仪,以Sc作内标,同时测定清洁水体中的Cu、Zn、Cr、Fe、Mn、Co、Ni,在X射线管电压30kV,管电流200μA,测定时间100s的条件下,运用点滴支持工具,方法检出限为3.1-5.1μg/L.地表水水样分析结果与ICP-Ms法相符,精密度较好,加标回收率在95%-123%之间.  相似文献   

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采用基于密度泛函理论的第一性原理计算方法,系统地研究了不同掺杂浓度下过渡族元素Cr、Mn、Co、Ni在Al13Fe4相中的占位情况、结构稳定性和机械性能. 计算得到所有的Al13(Fe24-xMx) (M=Cr、Mn、Co、Ni;X=1,2,4)相都具有良好的热力学稳定性和机械稳定性. 相同掺杂浓度化合物的形成焓按如下顺序减小:Al78(Fe24-xCrx) > Al78(Fe24-xMnx) > Al13Fe4 > Al78(Fe24-xNix) > Al78(Fe24-xCox).形成焓的降低增加了Al13Fe4相成核驱动力,Co和Ni有利于促进Al-Fe合金中Al13Fe4相形核,细化Al13Fe4相. 过渡族元素可以改善金属间化合物的脆性,增强塑性变形能力. 并且随着掺杂浓度的增加,过渡族元素的加入对脆性的改善呈先增大后减小的趋势.  相似文献   

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采用直流磁控溅射方法制备了一系列的合成反铁磁及以其为自由层的自旋阀.研究发现,在Ni81,Fe19与Ru层之间插入适当厚度的Co90Fe10层后,可有效地提高合成反铁磁两磁性层间的反铁磁耦合强度,得到具有饱和场日.更高、饱和磁化强度M.更低、热稳定性更好的合成反铁磁.另外,以这种合成反铁磁作自旋阀的自由层时,可有效提高自旋阀的稳定性.  相似文献   

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