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对非晶合金Fe78Si9B13进行了超短脉冲电流处理,实现了晶化时α-Fe(Si)单相结构析出.可以认为,脉冲电流作用时,电子运动与非晶中空位型结构缺陷间的周期性排斥效应促进了类金属原子从非晶结构单元中析出,使Fe(Si)原子局部富集,导致基体金属相在较低温度下优先成核.而在空位的定向迁移的同时,将伴随B原子的扩散,则B原子局域富集,Fe-B化合物的形核析出就要受到这两个因素的抑制
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利用XRD和TEM方法研究Fe42.5Al42.5Ti5B10合金在机械合金化及等温热处理过程中的结构演变及晶粒生长动力学,讨论了机械合金化合成机理和热处理过程中的晶粒生长机理.结果表明,球磨过程中Al,Ti,B原子向Fe晶格中扩散,形成Fe(Al,Ti,B)固溶体.机械合金化合成Fe(Al,Ti,B)遵循连续扩散混合机理.球磨50h后,金属Fe,Al,Ti,B已完全合金化,球磨终产物为纳米晶Fe(Al,Ti,B).球
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XRD
TEM
42.5Al42.5Ti5B10合金')" href="#">Fe42.5Al42.5Ti5B10合金
机械合金化 相似文献
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在0—300℃范围内考查了非晶Fe82Si5B13合金的磁导率等温弛豫动力学行为,给出了等时弛豫谱,观察到四个弛豫峰。测量表明,总的磁导率弛豫由两种弛豫过程组成,即对于退磁可逆的普通减落和对于退磁不可逆的磁导率连续衰减。计算了弛豫时间和激活能的分布,表明弛豫时间和激活能有宽的分布。普通减落和磁导率衰减过程的最可几激活能分别为1.0eV和1.4eV。对退火的样品,观察到磁导率先是增大而后是衰减的广义cross-over效应。
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L. I. Mirkin 《Russian Physics Journal》1966,9(3):73-76
Conclusions It has been shown by X-ray diffraction and metallographic investigation that a solid solution of gallium in tin is formed when liquid gallium is placed on the surface of solid tin or when a tin-gallium alloy is produced artifically by mixing the metals in the liquid state. The solid solution grains are not etched by some reagents in the same way as the grains of tin, and the microhardness of the solid solution is 42 ± ± 8 kg/mm2 compared with 12 ± 2 kg/mm2 for pure tin. Calculations on 24 X-ray reflections showed that the lattice constants of the tin decreased when the solid solution was formed: Constanta decreased from 5.818 to 5.777 Å, i.e., by 0.70%, and constant c decreased from 3.183 to 3.164 Å, i.e., by 0.60%. The direction of the changes in the lattice constants agree well with the cyrstallographic and chemical data on the ionic radii of tin and gallium.In conclusion the author wishes to express his gratitude to E. D. Shchukin, A. V. Pertsov, and N. V. Pertsov for contributing to the discussion of the results and to L. L. Krapivin for help in carrying out the experiments. 相似文献
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亚稳态FeCu固溶体微粉原子相互作用势的计算 总被引:3,自引:1,他引:2
本文介绍了亚稳态Fe50Cu50固溶体晶格常数的测量结果,应用金属结构的经典概念并考虑到原子核周围电子密度的高斯型球对称分布,导出了计算金属中一个原子的平均内能和两种不同金属原子相互作用势的普遍公式.对亚稳态Fe50Cu50合金原子相互作用势作计算,得到平衡时fcc-FeCu的晶格常数为0.36433 nm与实验测量结果接近,也与H.R.Gong等人对亚稳态FeCu合金的研究结论一致,证实了亚稳态Fe50Cu50合金是以fcc结构形式存在的固溶体. 相似文献
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The structural and composition characteristics of cadmium-mercury telluride solid solutions grown by the molecular beam epitaxy method have been investigated. It has been found that the x-ray diffraction method and energy dispersion microanalysis give the cadmium-content values in a solid solution differing by more than 10%. This difference is attributed to the compression of the crystal lattice due to a high density of point defects—mercury vacancies. 相似文献
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通过分子动力学研究了季戊四醇晶体在温度高达500K范围内的结构和振动性质。考察了季戊四醇晶体的晶格参数和分子构型等随温度变化情况,相对晶格常数a来说,晶格常数c容易被压缩。发现C-C,C-H和 C-O键随温度的变化较大,这意味着在分解过程中这些键可能较敏感,即最先断裂可能性较大。研究了季戊四醇晶体在不同温度下的振动,在常压下,我们所计算的振动频率高于实验结果,另外,我们还讨论了由温度引起的频率漂移。 相似文献
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通过分子动力学研究了季戊四醇晶体在温度高达500K范围内的结构和振动性质.考察了季戊四醇晶体的晶格参数和分子构型等随温度变化情况,相对晶格常数a来说,晶格常数c容易被压缩.发现C-C,C-H和C-O键随温度的变化较大,这意味着在分解过程中这些键可能较敏感,即最先断裂可能性较大.研究了季戊四醇晶体在不同温度下的振动,发现大部分频率随温度的升高而降低. 相似文献
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Phase stability of GaxMn1−xAs alloy with a zincblende structure over the whole Mn composition is investigated by means of the full-potential linearized augmented plane-wave method and the cluster expansion method, and role of a lattice constraint from substrate on the phase stability is discussed. The calculated results demonstrate a phase separated type phase diagram with a miscibility gap even when the lattice constraint by changing the lattice constant is imposed, where the critical temperature is found to decrease with increasing the lattice constant. Thus, the elastic constraint from the substrate acts to help stabilize a solid solution so as to realize the magnetic semiconductor with higher Mn composition. 相似文献
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V. K. Portnoi A. V. Leonov V. I. Fadeeva S. A. Fedotov 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(12):1693-1696
Specific features of the phase formation during mechanochemical synthesis of mixtures of elementary components, Ni, Al, and graphite, in an atomic ratio of 2:1:1 and a mixture of the intermetallic compound Ni3Al and graphite (1:1) have been considered. It is shown that nanocrystalline (D = 4–6 nm) three-component solid solutions Ni(Al, C) with identical lattice constants (a = 0.366 nm) are formed during mechanosynthesis, independent of the initial components. Annealing at a temperature of 800°C for 2 h leads to decomposition of solid solutions into three phases: double carbide Ni3AlC0.46 (a = 0.3592 nm), solid solution Ni(Al, C) with the lattice constant 0.3546 nm, and graphite with the lattice constants a = 0.2461 nm and c = 0.660 nm. 相似文献
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L. P. Bulat I. A. Drabkin V. V. Karataev V. B. Osvenski? D. A. Pshena?-Severin 《Physics of the Solid State》2010,52(9):1836-1841
This paper reports on a theoretical and experimental investigation of the behavior of the electrical and thermal conductivities
of a nanostructured material based on Bi
x
Sb2 − x
Te3 solid solutions. The effect of boundary scattering has been taken into account by introducing the scattering mechanism with
a constant mean free path equal to the nanoparticle size. A comparison with the results of the measurements has demonstrated
that one can describe satisfactorily the experimental dependences of the electrical and thermal conductivities on the nanoparticle
size by using only the parameters of the initial solid solution and its pure constituents. The estimates have revealed that
the lattice thermal conductivity of nanostructured materials can be reduced by 20–30% as compared to the initial solid solution
with nanoparticle sizes of the order of 20 nm, which should produce a favorable effect on the magnitude of the thermoelectric
figure-of-merit. 相似文献
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S. I. Sadovnikov A. A. Rempel 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(8):1174-1178
The short-range order and pair correlations in a square lattice in which some part of sites are occupied by A atoms and the other are vacant have been investigated by computer simulation. It is shown that, in the presence of interactions in the first coordination sphere of an A y □1 ? y solid solution with a square lattice, induced pair correlations damp only in the ninth coordination sphere. A functional dependence between the correlation in the first coordination sphere and the induced correlations in the next coordination spheres has been established for different compositions of the solid solution. 相似文献
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The collision-generated hybridization which has been found responsible for the on-site mixing of the atomic-likef-state and the band-liked states in mixed valence solids has been studied for the cerium solid. A practical expression which depends on the lattice
constant and temperature has been obtained for the collision-generated hybridization. Numerical calculations show that the
valence varies continuously with lattice constant and that temperature makes the transition smoother. The collision-generated
hybridization is found to be of significant strength in the intermediate valence regime; but over a wide range of the valence
near 3.5 it varies rather slowly without preferring a particular valence. Factors which can assist the collision-generated
hybridization in stabilizing the mixed valence phase at a particular lattice constant are discussed. 相似文献