共查询到20条相似文献,搜索用时 125 毫秒
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利用X射线衍射技术、差示扫描量热分析技术和透射电子显微镜研究了非晶态Cu56Zr44合金的结构及其等温退火条件下的晶化过程.实验结果表明,非晶态Cu56Zr44合金在室温下的短程结构类似于硬球无规密堆积分布.在703K过冷液相区内等温退火时发现,当退火时间为3min时,晶化产物主要为Cu8Zr3相;当退火时间为6min时,Cu8Zr3关键词:
非晶态
56Zr44合金')" href="#">Cu56Zr44合金
结构
等温退火 相似文献
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根据实验研究成果提出纳米晶合金软磁性能受其介观结构影响的观点,建立了Fe基纳米晶合金的球状介观结构模型,分别求出只有交变磁场或交变磁场和静磁场作用时纳米晶粒球的频率函数——D函数.分析表明,两种D函数都是复变函数,其实部Re(D)为纳米晶电感性质和电容性质的反映,虚部Im(D)为纳米晶电阻性质的反映,据此建立了Fe基纳米晶合金介观结构的等效RLC并联模型.由该模型求得合金产生极值巨磁电阻的条件为vextGMI=v|Re(D)=0,决定因素有μ,σ,ω,R和Hex及微观磁结构.
关键词:
Fe基纳米晶合金
等效RLC并联模型
球状介观结构模型
频率函数 相似文献
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Monica Sorescu Tianhong XuSteven Herchko 《Journal of magnetism and magnetic materials》2011,323(22):2859-2865
Differential scanning calorimetry, X-ray diffraction and room temperature Mössbauer spectrum measurements of Fe73.5Cu1Nb3Si13.5B9 (Finemet) alloy have been carried out in order to study its structural and magnetic properties as a function of annealing temperature. The DSC profile of as-quenched Finemet showed two exothermic peaks at 530 and 702 °C, corresponding to two crystallization processes. The Finemet alloy remains amorphous at 450 °C with one broad peak in XRD pattern and one broad sextet in Mössbauer spectrum. When the Finemet alloy was annealed at 550 °C, only well indexed body-center-cubic phase was detected. After being annealed at 650 and 750 °C, the XRD patterns showed the coexistence of α-Fe(Si) and Fe-B intermetallic phases with the increase in XRD peak intensities, indicating the growth of crystallites and the decomposition of Fe73.5Cu1Nb3Si13.5B9 alloy at elevated temperatures. The Mössbauer spectra of annealed Finemet alloy could be fitted with 4 or 5 sextets and one doublet at higher annealing temperatures, revealing the appearance of different crystalline phases corresponding to the different Fe sites above the crystallization temperature. The appearance of the nanocrystalline phases at different annealing temperatures was further confirmed by the recoilless fraction measurements. 相似文献
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在激光功率为40—160W、扫描速度为10mm/s、激光光斑为20mm照射条件下,用CO 2激 光辐照非晶Fe73.5Cu1Nb3Si13.5B9< /sub>产生微量晶化.利用透射穆斯堡尔谱 (TMS)技术分析了原始态和晶化后样品的超精细结构.确定了穆斯堡尔谱的基本参数——化 学位移(IS)、四极分裂(QS)、内磁场(Hhf)随激光功率变化的规律.分析表明,CO2关键词:
激光辐照
微量晶化
73.5Cu1Nb3 Si13.5B9')" href="#">非晶Fe73.5Cu1Nb3 Si13.5B9
穆斯堡尔谱 相似文献
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The local environment of Cu atoms in Fe73.5Cu1Nb3Si13.5B9 alloy was investigated by extended X-ray absorption fine structure(EXAFS).Cu clusters began to order when the annealing temperature was around 733 K from the results of the Fourier transform curves.The fitting results showed that the first shell of the near fcc(face-centered cubic)Cu clusters only contained Cu atoms.The coordination number increased with the annealing temperature.Subsequently,the occupancy rate increased from 33.3%(annealed at 733 K)to 100% (annealed at 853 K).This local structural change of Cu atoms could probably affect the distribution of the bcc(body-centered cubic)α-Fe in Fe73.5Cu1Nb3Si13.5B9 alloy. 相似文献
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The influence of nanocrystallization conditions on the structure, magnetic properties, and temperature stability of nanocrystalline magnetically soft Fe73.5Cu1Nb1.5Mo1.5Si13.5B9 alloy is studied. It is found that preliminary low-temperature annealing exerts an influence on subsequent nanocrystallization of the alloy. In addition, preannealing followed by nanocrystallization considerably improves the magnetic properties of the alloy. It is shown that the magnetic properties of the material can be controlled by varying the frequency of a magnetic field used for thermal treatment causing nanocrystallization. It is established that the magnetic properties of nanocrystalline Fe73.5Cu1Nb1.5Mo1.5Si13.5B9 alloy offer a high temperature stability. 相似文献
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根据用原子力显微镜对Fe基纳米晶Fe73.5Cu1Nb3Si13.5B9合金薄带的介观结构和巨磁阻抗效应的实验研究结果,提出了纳米晶软磁合金巨磁阻抗效应受其介观结构影响的理论模型.该模型成功地解释了低频对纳米晶软磁合金巨磁阻抗效应的影响,反映了现有“三明治”理论的主要特征,并弥补了它的不足;同时指出了纳米晶粒电导率σ、磁导率μ对合金巨磁阻抗效应有影响.
关键词:
铁基纳米晶合金
介观结构
巨磁阻抗效应
介观模型 相似文献
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The results obtained by partially substituting Ge for B and Si in the FINEMET alloy for the purpose of improving its magnetic properties at high temperatures are presented in this work. Nanocrystalline ribbons were obtained from controlled crystallization of amorphous material made employing the melt spinning technique. The studied compositions were: Fe73.5Si13.5Ge2Nb3B7Cu1 and Fe73.5Si13.5Ge4Nb3B5Cu1. The structural evolution of these alloys was studied using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) and these results were correlated with their magnetic properties at different annealing temperatures. The coercivity obtained for both alloys was below 1 A/m at anneling temperatures between 773 and 823 K. The amorphous saturation magnetization was satisfactory, almost 137 emu/g, comparable with that obtained for FINEMET alloys. The nanocrystallization and the Curie temperatures are dependent on Ge concentration. 相似文献