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1.
用XRD法研究了退火Fe73.5Cu1Nb3Si13.5B9合金中α-Fe(Si)晶化相的有序化过程,结果表明,Fe73.5Cu1Nb3Si13.5B9非晶合金在490℃,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7.0nm,它随退炎温度的升颃是长大,在590℃退火后达10.9nm,与α-Fe(Si)的尺寸相当,此时α-Fe(Si)的有序度为0.8,在850℃ 相似文献
2.
张湘义 《理化检验(物理分册)》1995,31(2):28-29,44
对Fe73.5Cu1Mo3Si13.5B9微晶软磁合金的结构及其对合金磁性的影响了研究,结果表明,在最佳磁性能下,晶相点阵常数a=0.2843nm,相当于Fe(Si)固溶体中含Si%(mol/mol):18-20,体积百分数V=74.8%,晶粒尺寸D=14.6nm;残余非晶层厚度δ=1.23nm;当T退火≥560℃时明显有Fe-B化合物析出。Fe73.5Cu1Mo3Si13.5B9合金的磁性不仅与 相似文献
3.
利用正电子湮没技术结合X-射线衍射分析了Fe73.5Cu1Nb3Si13.5B9纳变软磁合金在不同退火温度下,微观缺陷与相应相结构和软磁性能的变化规律。 相似文献
4.
用XRD法研究了退火Fe73.5Cu1Nb3Si13.5B9合金中α-Fe(Si)晶化相的有序化过程.结果表明,Fe73.5Cu1Nb3Si13.5B9非晶合金在490℃,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7.0nm,它随退火温度的升高而长大,在590℃退火后达10.9nm,与α-Fe(Si)的尺寸相当.此时,α-Fe(Si)的有序度为0.8在850℃,1h退火后,α-Fe(Si)的DO3超点阵线条消失.在550℃等温退火时,α-Fe(Si)的DO3有序畴先为椭球状,于60min退火后形成球状,直径为10nm. 相似文献
5.
研究了Fe73.5Cu1.0Mo3.0Sit13.5B9.0纳米磁软磁合金的磁性及其影响因素。结果表明,当退火温度为500-520℃时,合金具有最佳软磁性能,起始磁导率μi可达5×10^4。分析了磁性的影响因素。 相似文献
6.
机械球磨法制备纳米晶Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9的 总被引:1,自引:0,他引:1
对Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9成分的母合金进行了机械球磨,并对不同时间的球磨样品进行了X射线衍射(XRD)和Mossbauer谱(MS)的测量,结果表明样品难以完全非晶化,形成了无序的αFe-Si固溶体纳米晶,晶粒尺寸在5nm左右,同时共有一部分富集Nb,B元素的界面非晶相。在各种球磨条件下对αFe-Si固溶体中的Si含量进行了计算。纳米晶Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9软磁合金近年来受到了广泛的重视~[1]。这种材料通常是由熔融金属急冷制成非晶薄带,然后在晶化温度以上退火制成,晶化以后在非晶基体上均匀析出10-20nm尺寸的αFe-Si固溶体。机械球磨或机械合金化是近些年来发展起来的一种制备亚稳态材料如非晶,纳米晶,准晶等的有效手段,有一定优越性。本文利用机械球磨探讨一种制备纳米晶Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9合金粉末的新途径。 相似文献
7.
预退火对Fe73.5Cu1Mo3Si13.5B9纳米晶合金形成的影响 总被引:5,自引:0,他引:5
采用X射线衍射,电子衍射及透射电子显微技术研究了Fe73.5Cu1-xMo3Si13.5B9非晶合金410℃预退火对随后480℃退火所形成的纳米晶结构的影响。结果表明,预退火对Fe73。05,Cu1Mo3Si13.5B9合金纳米晶结构的形成有重要影响。当预退火时间从0小时增加到3小时,合金在480℃,小时退火形成的晶相化α-Fe(Si)的晶粒尺寸从15nm减小到8nm。预退火使α-Fe(Si)相的 相似文献
8.
研究了Nb含量x对Fe76.5-xCu1.j0NbxSi13.5B9.0纳米软磁合金的结构与磁性影响。研究结果表明,当Nb含量x约为3at%时,合金的软磁性能下合金显微组织结构中的aFe-Si纳米晶晶晶粒尺寸D、Si含量、体积分数Vc均呈下降趋势,非晶相的短程序有序范围δ增大;含金的磁性除与aFe-Si纳米晶有关外,还与合金中非晶相密切相关。用新近提出的双相无规磁各向异性模型讨论了合金的磁性与结构 相似文献
9.
10.
研究了520℃下等温退火Fe_(73.5)Cu_(1.0)Mo_(3.0)Si_(13.5)B_(9.0)纳米软磁合金的磁性,发现当退火时间ta为40min时,合金的起始磁导率μi最高,约为5×10~4,探讨了磁性的影响因素。 相似文献
11.
Magnetic micro-actuators and systems (MAGMAS) 总被引:2,自引:0,他引:2
Magnetic interactions provide outstanding performances for powerful integrated micro-actuators. This paper explains how magnetic interactions involving permanent magnets, currents, and various magnetic materials remain very effective and even improve as dimensions are reduced. The technological problems that have slowed the development of magnetic micro-actuators and systems (MAGMAS) are progressively being solved. As long as materials scientists continue to develop better thick-film patterned permanent magnets compatible with microsystem technologies, MAGMAS will have a promising future. 相似文献
12.
Zheng Y Wu Y Lil K Qiu J Han G Guo Z Luo P An L Liu Z Wang L Tan SG Zong B Liu B 《Journal of nanoscience and nanotechnology》2007,7(1):117-137
The high density and high speed nonvolatile MTJ MRAMs are reviewed from perspective of the reading and writing operation. The reading operation of the MRAM with different sensing schemes and cell array structures is discussed, in particular the reference resistance generating schemes which are introduced to maximize the cell efficiency and reading reliability. The high density, low cost cross-point cell layout structures are analyzed systematically. The writing operation modes ranging from the half-select, toggle mode, guided SAF direct writing, thermally assisted writing, to the spin transfer switching are investigated both theoretically and experimentally. The thermal factor always plays an important role in determine not only the thermal stability but also the reading and writing reliability. 相似文献
13.
研究了Nb含量x对Fe_(76.5-x)Cu_(1.0)Nb_xSi_(13.5)B_(9.0)纳米软磁合金的结构与磁性影响。研究结果表明,当N6含量x约为3at%时,合金的软用性能最高;随Nb含量x的增加,最佳软磁性能下合金显微组织结构中的αFe-Si纳米晶晶粒尺寸D、Si含量、体积分数V_c均呈下降趋势,非晶相的短程有序范围δ增大;合金的磁性除与αFe-Si纳米晶有关外,还与合金中非晶相密切相关。用新近提出的双相无规磁各向异性模型讨论了合金的磁性与结构的关系。 相似文献
14.
F. Giovannelli M. Zaghrioui C. Autret-Lambert F. Delorme A. Seron T. Chartier B. Pignon 《Materials Chemistry and Physics》2012
The synthesis of Ni1−xMnx(OH)2(CO3)x/2·nH2O Layered Double Hydroxides (LDHs) for x = 0.2, 0.25 and 0.33, their characterisation by electron microscopy, X-ray diffraction and their magnetic properties are reported in this study. When x increases, the crystallinity of the nanoparticles is improved. The low temperature magnetic behaviour of these compounds is characteristic of the competition between in plane ferromagnetic and interlayer antiferromagnetic interactions. The ferromagnetism is due to in plane Ni cations interaction and decreases when manganese content increases (Tc decreases from 26 to 15 K when x increases from 0.2 to 0.33). It was found that the substitution of Ni by Mn ions favours the in plane antiferromagnetic order. This study demonstrates that magnetic interactions occur in LDH with non magnetic interlayer anions. 相似文献
15.
Rh2O3(III) crystallizes with an orthorhombic corundum-related structure and is Pauli paramagnetic. Its electrical behavior is characterized by a small activation energy, and the Seebeck coefficient indicates p-type conduction. This oxide may be considered as a semimetal, and its properties are discussed in terms of face and edge sharing of RhO6 octahedra. 相似文献
16.
We proposed a novel technique to fabricate colloidal crystals by using monodisperse SiO(2) coated magnetic Fe(3)O(4)(SiO(2)/Fe(3)O(4)) microspheres. The magnetic SiO(2)/Fe(3)O(4) microspheres with a diameter of 700?nm were synthesized in the basic condition with ferric sulfate, ferrous sulfate, tartaric acid and tetraethyl orthosilicate (TEOS) in the reaction system. Monodisperse SiO(2)/Fe(3)O(4) superparamagnetic microspheres have been successfully used to fabricate colloidal crystals under the existing magnetic field. 相似文献
17.
F. Kromer N. Oeschler T. Tayama K. Tenya T. Cichorek M. Lang F. Steglich J. S. Kim G. R. Stewart 《Journal of Low Temperature Physics》2002,126(3-4):815-833
We report on recent magnetic field studies on U
1–xThxBe
13
with x0.1. These new results are related to previous data published by Kromer et al. [F. Kromer et al., Phys. Rev. B 62, 12477 (2000)]. The new magnetization measurements confirm the existence of an anomaly found earlier through calorimetric and dilatometric measurements at T
L
c
for x
c1
0.019. In the critical concentration range x
c1
c2
0.0455, the critical-field curves for the mean field type of phase transition that occur at T
c1
and T
c2
(at zero field) appear to merge as T0. This interesting fact which has been inferred already from the previous measurements could be confirmed for a sample with x=0.038. The normal state for Th concentrations xxc2
is rather unusual: A negative normal-state contribution, n, is observed in the thermal expansion coefficient as well as the occurrence of a positive peak when superconductivity is suppressed by a magnetic field. Both effects are studied in detail and a comparison to specific heat results is given. Finally, we have investigated the non-linear contribution to the magnetization,
(3)
, of UBe
13
and U
0.9
Th
0.1
Be
13
. In contradiction to suggestions made previously by Aliev et al. [Aliev et al., Europhys. Lett. 32, 765 (1995)] for x=0.1,
(3)
remains negative down to T100 mK, the lowest temperature investigated. 相似文献
18.
McLain SE Dolgos MR Tennant DA Turner JF Barnes T Proffen T Sales BC Bewley RI 《Nature materials》2006,5(7):561-566
Fluoride phases that contain the spin-1/2 4d9 Ag(II) ion have recently been predicted to have interesting or unusual magnetochemistry, owing to their structural similarity to the 3d9 Cu(II) cuprates and the covalence associated with this unusual oxidation state of silver. Here we present a comprehensive study of structure and magnetism in the layered Ag(II) fluoride Cs2AgF4, using magnetic susceptometry, inelastic neutron scattering techniques and both X-ray and neutron powder diffraction. We find that this material is well described as a two-dimensional ferromagnet, in sharp contrast to the high-T(C) cuprates and a previous report in the literature. Analyses of the structural data show that Cs2AgF4 is orbitally ordered at all temperatures of measurement. Therefore, we suggest that orbital ordering may be the origin of the ferromagnetism we observe in this material. 相似文献
19.
J. Gosk M. Zajac M. Byszewski M. Kamiska J. Szczytko A. Twardowski B. Strojek S. Podsiado 《Journal of Superconductivity》2003,16(1):79-82
Wurtzite (Ga,Fe)N bulk crystals were, for the first time, successfully grown by AMMONO and chemical transport methods. The magnetization measurements of (Ga,Fe)N crystals revealed the coexistence of paramagnetic and ferromagnetic contributions. The paramagnetic component was shown to be growth condition dependent. The Brillouin-type behavior was observed in the samples obtained by both methods. Some (Ga,Fe)N samples (especially those codoped with Si) grown by the chemical transport method show a Van Vleck–type paramagnetic behavior. 相似文献
20.
Magnetic properties of new (NP) hydrothermal particles 总被引:1,自引:0,他引:1
Corradi A. Andress S. French J. Bottoni G. Candolfo D. Cecchetti A. Masoli F. 《IEEE transactions on magnetics》1984,20(1):33-38
A new type of uniaxial particles for magnetic recording whose precursors are produced via an original hydrothermal process was recently introduced in the market. The characterizing feature of these materials is their extremely uniform size and ellipsoidal shape. Most of their properties can be ascribed to the lack of external (pores, dendrites, sharp edges) as well as internal (because of ellipsoidal shape) - self-demagnetizing sources, which suggests the name of "Non-Polar (NP)" particles. As a result of this morphology, they show unique magnetic properties. The magnetization reversal mechanism is not accounted for by any known mechanism as fanning or curling and the rotational hysteresis gives very sharp Wr vs. H curves with the lowest values for the integral ever measured for particulate media. The behaviour of coercivity versus packing fraction for Cobalt-surface-modified NP particles is described by a new "constricted magnetization" model. The reasons for these unique characteristics and the practical impact that these materials may have in the field of magnetic recording are discussed. 相似文献