新型纳米晶软磁合金及其应用(一)

最近十年来纳米磁性材料已经获得了广泛的应用.本文详细论述了由两个铁磁相组成的新型纳米晶软磁合金在理论研究和实际应用方面所取得的重要成果.重点介绍了随机各向异性模型在解释这类纳米晶软磁合金的微结构特征和磁性能方面的成功应用,以及各种纳米晶软磁合金,包括Fe-Si-B-Cu-Nb纳米晶合金、Fe (Co)-Zr-B-(Cu)纳米晶合金、Fe-M-N, C (M = Zr, Hf, Ta, Nb)薄膜、软磁颗粒膜、双相非晶态薄膜和磁性多层膜作为高频软磁材料应用的最新进展情况.     

Ce3Rh2X2(X=Ga,Ge)的磁性模拟和晶场效应研究

根据晶场理论,通过对Kaczorowski研究小组磁化率倒数与温度关系曲线的模拟,得到了稀土化合物Ce3Rh2Ga2和Ce3Rh2Ge2的晶场分裂能和相应波函数,它们的第一激发能和总激发能分别为3.62 meV,39.0meV和11.7 meV,61.5meV.计算表明,Kramers离子Ce3+在晶场效应的作用下,基...     

铁基纳米晶软磁合金的研究现状

纳米晶软磁合金具有较高饱和磁感应强度、高磁导率、低高频损耗等特点.对牌号为Finemet、Nanoperm和Hitperm等三类铁基纳米晶软磁合金进行了分类综述,分别介绍了各类合金的成分、性能、显微组织结构特点以及应用范围,并对它们的非晶晶化过程机理以及影响合金软磁性能的因素进行了简要讨论.     

Tuning electronic,magnetic, and transport properties of blue phosphorene by substitutional doping: a first-principles study

Using first-principles density functional theory, we investigated the geometrical structure and magnetic, electronic, and transport properties of blue phosphorene doped with a multitude of substitutional impurities, including both metallic and semiconducting elements. Substitutional dopants modified the properties of blue phosphorene. B, Al, Ga, Sb, Bi, and Sc substitutional dopants led to an indirect- to direct-gap transition. Blue phosphorene with C, Si, Ge, Sn, O, S, Se, and Fe substitutional dopant atoms showed dilute magnetic semiconducting properties. Furthermore, the effective mass as well as zero-bias transmission spectrum of this material support the fact that the transport properties of blue phosphorene are modified by the above-mentioned impurity atoms. The effective mass of holes for the Bi- and Sb-doped systems was about \(0.138m_{0}\), implying that these systems have high hole mobility. Meanwhile, the Sb-doped system exhibited the smallest effective mass for electrons of \(0.244m_{0}\). The results of this study illustrate that doped blue phosphorene exhibits different electronic, magnetic, transport, and optical properties from pristine blue phosphorene, which may enable many useful applications in nanoelectronics, gas sensing, optoelectronics, and spintronics.     

Fe-Pt纳米晶永磁合金薄膜研究现状

Fe_Pt纳米微晶永磁薄膜材料由于在高密度磁记录材料领域、微电机械和医用器械领域具有良好的应用前景而受到广泛关注。本文简述了Fe_Pt纳米微晶永磁薄膜的研究现状,介绍了该类永磁材料的结构特点和交换耦合作用机理,重点叙述了有关制备工艺和添加元素对改进其磁性能影响的研究。     

热处理温度对Fe_(83.5)B_(15)Cu_(1.5)合金结构及性能影响

通过熔体快淬法制备具有(200)取向α-Fe晶粒的Fe83.5B15Cu1.5非晶纳米晶合金,并重点研究了在制备过程中α-Fe晶粒的产生以及贴棍面和自由面对合金结构与磁性能的影响规律。研究表明,Fe83.5B15Cu1.5合金在熔体快淬之后具有大量(200)择优方向的α-Fe晶粒。晶化热处理之后,贴辊面的微观形貌主要是球形纳米颗粒,而自由面的微观形貌主要是长度为200~300nm的片状多孔结构。经过热处理(温度390℃,保温时间10min)之后可获得最佳磁性能为:饱和磁感应强度Bs=1.83T,矫顽力Hc=8.7A/m。本研究对Fe基非晶合金软磁材料的发展具有积极意义。     

Magnetic core properties and their thermal stability in a BCC Fe-Zr-B-Cu alloy with nanoscale grain size

A mostly single bcc phase with nanoscale grain size of 10 to 20 nm has been found to form by annealing amorphous Fe-Zr-B, Fe-Hf-B and Fe-M-B-Cu (M = Ti, Zr, Hf, Nb and Ta) alloys. It has further been clarified that the newly developed nanocrystalline bcc alloys exhibit high permeability (μ_e) combined with high saturation magnetization (B_s). Subsequently, the possible application potentials of the bcc alloys were investigated. The core loss is as small as 66 mW/kg at 1 T and 50 Hz for a nanocrystalline bcc Fe₈₆Zr₇B₆Cu₁ alloy obtained by annealing for 3.6 ks at 873 K. This value is 45 and 95 percent smaller than those for amorphous Fe₈₆Si₉B₁₃ alloy and Fe-3.5 percent Si alloy, respectively, which are presently in use as core materials in electric power transformers. The frequency dependence of the core loss for the bcc alloy at 0.2 T is almost the same as that for an amorphous Co_70.5Fe_4.5Si₁₀B₁₅ alloy with zero magnetostriction. In the frequency range of 10 to 300 kHz, the core loss for the bcc alloy is slightly smaller than the Co base amorphous which has been used as core material in high-frequency transformers. Furthermore, the core losses of the nanocrystalline Fe₈₆Zr₇B₆Cu₁ alloy also were found to have high stability against thermal aging. Thus, nanocrystalline bcc Fe-Zr-B-Cu alloys with the advantages of high B_s, high μ_e, and low core loss is expected to be used as a core material in various transformers.     

Research on performance improvement of magnetostrictive vibration power generator by frame material

As the performance of modules improved and the Internet became widespread, various electric appliances in daily life became connected to the Internet. Along with this, related to the method of supplying power to the module, attention is being paid to energy harvesting such as vibrational power generator. A magnetostrictive vibration generator comprising a magnetostrictive material (Fe‐Ga alloy) and a vibrating material is a promising device capable of generating small size and high power. However, selection of the optimum vibration material and analysis of the magnetic circuit for the magnetic characteristics of the Fe‐Ga alloy were insufficient, and it was thought that the vibration power generation device could not fully demonstrate the performance. In this paper, magnetic properties of monocrystalline Fe‐Ga alloy and vibrating material are grasped and magnetic analysis using finite element method is carried out. In addition, actually samples were prepared and compared with the results of magnetic analysis. From this result, we examined the effect of combinations of materials on device performance.     

Nb添加量对FeBCu纳米晶合金组织结构、磁性能和退火脆性倾向的影响

为改善FeBCu系纳米晶软磁合金的热处理工艺性,抑制其退火脆性倾向,利用X射线衍射仪、透射电子显微镜、差示扫描量热仪、振动样品磁强计和平板弯曲实验等测试手段,研究了Nb含量对Fe_86-xB₁₃Cu₁Nb_x(x = 0~6)急冷合金条带的结构、热性能、结晶化组织、磁性能和退火脆性倾向的影响。结果表明：增加Nb量可有效提高非晶相的热稳定性、细化热处理后合金的α-Fe晶粒尺寸并改善其软磁性和退火脆性。其效果在Nb含量＞2 at.%尤为显著,而当Nb含量 ≥ 5 at.%时趋于平缓。纳米晶合金退火脆性的改善主要源于其α-Fe晶粒尺寸和体积分数的降低。     

Nb添加量对FeBCu纳米晶合金组织结构、磁性能和退火脆性倾向的影响

为改善FeBCu系纳米晶软磁合金的热处理工艺性,抑制其退火脆性倾向,利用X射线衍射仪、透射电子显微镜、差示扫描量热仪、振动样品磁强计和平板弯曲实验等测试手段,研究了Nb含量对Fe_86-xB₁₃Cu₁Nb_x(x = 0~6)急冷合金条带的结构、热性能、结晶化组织、磁性能和退火脆性倾向的影响。结果表明：增加Nb量可有效提高非晶相的热稳定性、细化热处理后合金的α-Fe晶粒尺寸并改善其软磁性和退火脆性。其效果在Nb含量＞2 at.%尤为显著,而当Nb含量 ≥ 5 at.%时趋于平缓。纳米晶合金退火脆性的改善主要源于其α-Fe晶粒尺寸和体积分数的降低。     

Mn对FeCuSiBNb纳米晶合金的高频磁特性和微观结构的影响

通过差示扫描量热仪（DSC）、X射线衍射仪（XRD）、透射电子显微镜（TEM）、磁光克尔显微镜（MOKE）、直流B-H仪和阻抗分析仪等手段研究了Mn元素对FeCuSiBNb合金的热稳定性、高频磁性能、微观结构和磁畴的影响。结果表明：Mn元素对合金的第一与第二晶化温度区间和矫顽力的影响非常小,但可提高合金的高频磁导率和适用退火温度区间。与无Mn合金相比,Mn掺杂合金在10 kHz下磁导率可提高36.5%,且可抑制Fe₃B相的析出。这种良好的高频特性可归因于Mn元素的掺杂降低了纳米晶合金的平均晶粒尺寸,改善了磁畴结构的均匀度,从而降低了钉扎场。     

触变剂对环氧树脂封装铁基纳米晶磁芯软磁性能的影响

用宽为20 mm、厚为25μm的Fe73.5Cu1Nb3Si13.5B9非晶带材绕制成环形磁芯,经550℃×100 min晶化退火处理制成纳米晶磁芯,并对其进行环氧树脂封装,分析了触变剂对磁芯性能的影响。结果表明,与封装前相比,封装后纳米晶磁芯的磁导率μ、饱磁感应强度Bs、磁滞损耗Pu、磁芯电感Ls和感应电动势E随着触变剂含量的减小而减小;而矫顽力Hc和剩磁Br则随着触变剂含量的减小而增大。     

添加合金元素对Pr-Fe-B永磁合金结构和磁性能的影响

简述了Co,Nb,Zr,Ga,Cu,Si等合金元素的加入对Pr-Fe-B永磁合金的结构和磁性能的形响情况，以上合金元素的加入，均能不同程度的提高Pr-Fe-B的磁性能，但含量超过一定比例后，磁性能则有所下降，Co,Cu,Si的加入还有助于Pr-Fe-B合金居里温度的提高。     

近十年来大功率磁性技术软磁材料发展的回顾与分析（四）

评述了大功率磁性技术中软磁材料的近十年发展史,所介绍的材料包括：硅钢、坡莫合金、软磁铁氧体、非晶和纳米晶合金、软磁复合材料等,并且分析了发展中的一些问题。     

近十年来大功率磁性技术软磁材料发展的回顾与分析（三）

评述了大功率磁性技术中软磁材料的近十年发展史,所介绍的材料包括：硅钢、坡莫合金、软磁铁氧体、非晶和纳米晶合金、软磁复合材料等,并且分析了发展中的一些问题。     

Formulation and mixing conditions of magnetic composite materials used for magnetic wedges in an interior permanent magnet synchronous motor

An interior permanent magnet synchronous motor (IPMSM) is characterized by its high efficiency. However, torque ripple and loss occur because of the spatial harmonics generated by air-gap permeance fluctuations. This study clarified that slot harmonic components can be suppressed by inserting magnetic wedges made of magnetic composite material in the slot opening of an IPMSM. First, the authors examined the torque and loss characteristics by varying relative permeability and saturation magnetic flux density of magnetic wedges using finite element analysis (FEA). Results indicated that the torque ripple and loss could be suppressed when the relative permeability of the magnetic wedge was μ_r = 10 to 22 and the saturation magnetic flux density was B_s = 0.5 to 0.75 T. Furthermore, the authors produced magnetic composite materials made of various soft magnetic material powders and examined their magnetic properties and viscosities. Results showed that a magnetic composite material with optimal magnetic properties and injectable viscosity could be manufactured using Fe-Si-Al with a low volume fraction.     

合金成份对各向同性FeCrCo合金磁性能的影响

以Fe59Cr23Co15Mo3合金为基础,系统地研究了成份以及添加合金化元素Si、V和Ti对合金磁性能的影响。实验表明,合金中Cr含量的适当增加提高了合金的Hc,降低了合金的Br。适量合金化Si、V和Ti的加入,分别起到了提高合金磁能积、降低合金固溶温度和改变冷却方式以及大幅度提高合金Hc的作用。通过实验,Fe54Cr27Co15Mo3Ti1合金的各向同性磁性能为:Br=0.7405T,Hc=50.13kA/m,(BH)m=13.69kJ/m3,为本研究获得的最佳性能。     

超微晶磁芯及其在开关电源中的应用

超微晶亦称纳米非晶，它是一种新型磁性材料。超微晶磁芯具有高磁导率、高矩形比、磁芯损耗低、高温稳定性好等优点而倍受人们青昧。以德国VAC公司生产的铁基超微晶磁芯VITROPERM 500F、钴基超微晶磁芯VITROVAC 6025Z为例，介绍其性能特点以及在开关电源中的应用。     

溅射功率对CoFeB薄膜磁与结构特性的影响

以不同功率溅射制备了CoFeB合金薄膜样品并在高真空下退火处理。发现低功率生长的薄膜始终具有磁各向同性,而高功率生长的薄膜随着退火温度的升高,由起始的单轴磁各向异性逐渐向磁各向同性转变。X射线衍射分析也印证了CoFeB薄膜随退火温度的升高,薄膜由非晶态逐渐向结晶态转变。当退火温度高于400℃时,低功率生长的CoFeB样品的矫顽力大于高功率生长薄膜的矫顽力。同时发现低功率生长的CoFeB的(110)峰值高于高功率生长的样品峰值,表明低功率生长的薄膜晶粒尺寸更大。     

近十年来大功率磁性技术软磁材料发展的回顾与分析（二）

评述了大功率磁性技术中软磁材料的近十年发展史,所介绍的材料包括：硅钢、坡莫合金、软磁铁氧体、非晶和纳米晶合金、软磁复合材料等,并且分析了发展中的一些问题。