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在Ni0.5Zn0.5Nd0.02Fe1.98O4纳米粒子表面原位聚合苯胺制备了Ni0.5Zn0.5Nd0.02Fe1.98O4-聚苯胺(PANI)纳米复合材料.铁氧体含量为0%、15%和30%样品的结构、形貌和电磁性能分别采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和HB8510B网络分析仪进行了研究.结果表明,聚苯胺包覆层对Ni0.5Zn0.5Nd0.02Fe1.98O4的结晶度有一定影响.在X波段(8.2~12.4 GHz),复介电常数的实部随铁氧体含量的增加而减小,虚部随铁氧体含量的增加而增大.复磁导率的实部和虚部都随铁氧体含量的增加而增大. 相似文献
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对短碳纤维进行氧化处理后,采用原位氧化沉淀聚合法使苯胺/磁流体或者苯胺/磁粉在其表面进行包覆反应,制备出具备有一定长径比的导电导磁改性短碳纤维.采用扫描电镜、X射线能谱及X射线衍射对改性碳纤维的形貌、化学组成进行了分析,利用PNA-LN5230A微波网络测试仪测定了其在频率2GHz以下的复介电常数和复磁导率,对比分析了两种不同方法制备的改性碳纤维的电磁参数以及2mm厚度下的吸收损耗.结果表明:聚苯胺/磁流体包覆的碳纤维(改性SCF-A)包覆层完整、致密,Fe含量为2.86at%;聚苯胺/磁粉包覆碳纤维(改性SCF-B)的包覆层外观完整、比较松散,Fe含量为3.12at%.改性SCF-A的复介电常数的实部大于改性SCF-B,但其虚部则小于改性SCF-B;改性SCF-B的复磁导率整体大于改性SCF-A.在频率2GHz以下,改性SCF-A的最大吸收损耗为3.06dB,改性SCF-B的最大吸收损耗为4.14dB. 相似文献
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铁、镍及其合金纳米粒子的制备及电磁性能研究 总被引:2,自引:0,他引:2
利用直流电弧等离子法在105Pa H2 Ar混合气氛下制备了Fe,Ni及FeNi合金纳米粒子,通过XRD,TEM,XPS,VSM及TC-436(LECO LTD.)N/O分析仪等对纳米粒子结构、形貌、成分、表面状态及静态磁性能进行了表征,并通过矢量网络分析仪,利用同轴波导的方法对金属纳米粒子进行了电磁参数的测定.结果发现:在2~8GHz频率范围内,Fe,Ni,FeNi合金纳米粒子/固体石蜡复合材料的复介电常数虚部ε″在3~4,7~10,14~16GHz频段均出现三个峰值,随着Fe元素含量的增加,FeNi合金纳米粒子的复介电常数ε″损耗值成规律性的增加;复磁导率实部μ′也逐渐增大,且在2~4GHz范围出现极大值,复磁导率虚部μ″吸收峰值向高频段移动,而且当成分(质量分数/%)为Fe49.00Ni和Fe28.35Ni时,材料的吸收频带展宽. 相似文献
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利用直流电弧等离子体法在甲烷气氛中制备碳包覆磁性镍纳米胶囊(Carbon-coated Ni nanocapsules,Ni(C)NCs),将它作为电磁波吸收剂,按照质量比10%、20%、30%和40%与有机石蜡基体复合,在0.1~18GHz范围内测定其复介电常数和复磁导率,并对其电磁波响应特性及吸收机制进行了研究。研究结果表明,Ni(C)纳米胶囊具有明显的极化损耗特征,其介电常数在低频范围内随频率提高而急剧衰减,而磁导率具有宽化的多重共振峰;随着Ni(C)纳米胶囊添加量的增加,其介电常数逐渐增加,其复磁导率实部和虚部分别在0.1~8GHz、0.1~10GHz出现增加,而在8~18GHz和10~18GHz范围内出现实部减小和虚部平缓变化的特征。根据极化、涡流以及反射损耗的理论分析,发现Ni(C)纳米胶囊以介电损耗为主,并对相关机制进行了探讨。 相似文献
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二氧化硅包覆片状金属磁性微粉电磁特性分析 总被引:1,自引:0,他引:1
以Na2SiO3溶液为前驱体,稀H2SO4为催化剂在乙二醇溶剂中对片状金属磁性微粉进行表面包覆.用SEM、XRD、RA-IR,VSM等分析手段对包覆前后的金属磁性微粉进行分析表征,并对包覆前后SiO2/金属磁性微粉复合材料的复介电常数和复磁导率等微波(2~18GHz)电磁参数进行了测试.结果表明Na2SiO3溶液在以稀H2SO4为催化剂的条件下在磁性微粉表面以非晶态的形式生长了一层致密、均匀的高电阻率SiO2薄膜,该薄膜使磁性微粉在复磁导率变化不大的情况下,有效降低了磁性微粉的复介电常数. 相似文献
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研究了MnZn高磁导率铁氧体材料在Fe2O3含量不变的前提下,增加ZnO量,起始磁导率、品质因数、饱和磁感应强度及其与温度、频率的关系.结果表明,加入ZnO可以提高起始磁导率,饱和磁感应强度Bs和居里温度降低;当ZnO含量不超过25%mol时,高磁导率MnZn铁氧体材料有着良好的频率特性,但ZnO含量超过25mol%时,由于Zn2+是非磁性离子,且ZnO挥发严重,相反会使得起始磁导率μi下降. 相似文献
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Ceramic composites consisting of ferroelectric
and ferrite (
were synthesized by the mixed oxide route. The phase assemblage, electrical and magnetic properties of the samples were investigated. The results indicates that the
phase is compatible with (
phase, and dense diphasic composite ceramics were obtained. Electrical resistivity of composites varies with increasing amounts of (
phase, and shows a percolation-like drop. Magnetic hysteresis loops were observed in the composites. 相似文献
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本文用溶胶-凝胶自燃烧法制备了Ni0.5Zn0.5Fe2O4粉末颗粒,以甲醛为还原剂在Ni0.5Zn05Fe2O4颗粒表面进行了化学镀铜,制备了Cu/Ni0.5Zn0.5Fe2O4复合粉体.用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对镀铜前的Ni0.5Zn0.5Fe2O4颗粒以及镀铜后的复合纳米颗粒进行了表征.对镀铜前的Ni0.5Zn0.5Fe2O4粉体和不同镀铜量的Cu/Ni0.5Zn0.5Fe2O4复合粉体进行了电磁性能的研究,结果表明镀铜后镍锌铁氧体的吸波性能明显提高,增重量为65%的Cu/Ni0.5Zn0.5Fe2O4复合粉体在频率为11GHz处反射率可达-12dB左右. 相似文献
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The magnetic properties and anisotropy of amor-phous(Fe_(80)Ni_(20))_(78)Si_xB_(22-x).alloys have been investigatedsystematically.The maximum permeability,coercive forceand remanence have been determined for as-prepared andannealed samples,The results on the technical magneticproperties of this alloy system have been discussed andcompared with Masumoto's. 相似文献
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以Fe-Ni-Ti-Al 为助烧剂, 用热压的方法制备了TiB2 基金属陶瓷。研究了烧结温度、烧结时间、助烧剂对材料显微结构和力学性能的影响, 初步分析了TiB2 基金属陶瓷的增韧机理。结果表明, 随着烧结温度的提高, 材料弯曲强度降低, 洛氏硬度升高;随着烧结时间延长, 弯曲强度出现峰值。SEM、EDS 观察表明, 助烧剂中的Ti 避免了Fe2B、Ni23B6 等脆性相的生成, Al 有除氧的作用。裂纹偏转和裂纹桥联是TiB2 金属陶瓷重要的增韧方式。 相似文献
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热处理对电沉积Fe-Ni-S非晶合金结构与性能的影响 总被引:1,自引:0,他引:1
以硫脲为硫源、硼酸为缓冲剂、柠檬酸三钠为络合剂及糖精和1,4丁炔二醇为添加剂的酸性镀液中电沉积了Fe-Ni-S非晶合金薄膜。采用差示扫描量热(DSC)、X射线衍射(XRD)和扫描电镜(SEM)研究了该合金的晶化行为和表面微观形貌。结果表明,镀态Fe-Ni-S合金呈非晶态结构,250℃热处理出现了Fe_7Ni_3(I_(mam))微晶,320.4℃开始晶化出现NiS(R_(3m))相和FeNi_3(P_(m3m))相,417.9℃下大量晶化生成NiS(R_(3m))相和FeNi_3(P_(m3m))相,500℃时合金完全晶化生成许多粒径约为100-200 nm均匀颗粒。研究了热处理对合金薄膜的磁性能、显微硬度和耐腐蚀性能的影响。250℃以下,随着退火温度升高,薄膜的磁性能、显微硬度和耐腐蚀性能不断提高,然后下降。250℃热处理时,合金薄膜饱和磁化强度、硬度和电化学阻抗达到最大(Ms≈1201.1 kA/m,Hv≈425.4 kg/mm~2,Z′≈400Ω),而矫顽力最小(H_C≈2.1 kA/m)。因此250℃热处理的合金镀层软磁性能最佳,耐腐蚀最好。 相似文献
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Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys
The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis. 相似文献
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Md. Obaidullah Takeshi Furusawa Iqbal Ahmed Siddiquey Masahide Sato Noboru Suzuki 《Advanced Powder Technology》2017,28(10):2678-2686
Alumina (Al2O3) coated ZnO core-shell structures were synthesized by a novel, fast, and facile route utilizing microwave (MW) irradiation to control photocatalytic property of ZnO. The phase analysis and the core–shell structure development were corroborated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), X-ray fluorescence (XRF), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) analysis and Fourier transform infrared spectroscopy (FT-IR). The XPS results affirmed that elements on the coated surface were Al and O. Zeta potential analysis predicted the presence of Al2O3 layer on ZnO due to almost similar zeta potential curve for pure Al2O3 and Al2O3 coated ZnO nanoparticles. There was no significant change in band gap energy of ZnO after amorphous Al2O3 coating as obtained from derived data of the reflectance spectra but gradual decreasing of reflectance in the visible range, measured by UV–vis spectroscopy, of the prepared core-shell nanoparticle may be due to the coating of amorphous Al2O3 on ZnO. The photocatalytic efficiency of ZnO was reduced after amorphous Al2O3 layer as confirmed by the photodegradation of methylene blue under UV irradiation. 相似文献