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1.
基于几何遮蔽效应和法拉第旋光效应耦合的磁流体偏振光透过率 总被引:1,自引:0,他引:1
根据几何遮蔽效应和法拉第旋光效应耦合原理给出的解析表达式,通过数值模拟计算,研究了磁流体的纵场诱导偏振光透过率及磁流体的浓度、液态介电常量、磁性颗粒磁偶极矩热能比和单位磁性颗粒团聚体所含磁性颗粒数量四个参量的变化对其偏振光透过率的影响.结果表明,磁流体的浓度、液态介电常量和磁性颗粒磁偶极矩热能比对其偏振光透过率有显著影响,低浓度样品的偏振光透过率随着纵向磁场强度的增大而线性增加,而高浓度样品则随着纵向磁场强度的增大呈现振荡变化的特性.在一定范围内,磁流体偏振光透过率随其液态介电常量εliquid和磁性颗粒磁偶极矩热能比μd/(kT)的变大而增加.而单位磁性颗粒团聚体所含磁性颗粒数量对其偏振光透过率没有影响,磁流体参量依赖的偏振光透过率在低磁场区域和高磁场区域有明显区别.提出了磁流体纵场诱导偏振光透过率在几类光子器件中的可能应用. 相似文献
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根据几何遮蔽效应和法拉第旋光效应耦合原理给出的解析表达式,通过数值模拟计算,研究了磁流体的纵场诱导偏振光透过率及磁流体的浓度、液态介电常量、磁性颗粒磁偶极矩热能比和单位磁性颗粒团聚体所含磁性颗粒数量四个参量的变化对其偏振光透过率的影响.结果表明,磁流体的浓度、液态介电常量和磁性颗粒磁偶极矩热能比对其偏振光透过率有显著影响,低浓度样品的偏振光透过率随着纵向磁场强度的增大而线性增加,而高浓度样品则随着纵向磁场强度的增大呈现振荡变化的特性.在一定范围内,磁流体偏振光透过率随其液态介电常量εliquid和磁性颗粒磁偶极矩热能比μd/(kT)的变大而增加.而单位磁性颗粒团聚体所含磁性颗粒数量对其偏振光透过率没有影响,磁流体参量依赖的偏振光透过率在低磁场区域和高磁场区域有明显区别.提出了磁流体纵场诱导偏振光透过率在几类光子器件中的可能应用. 相似文献
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在基底与靶材之间放置磁性强弱不同的永久磁铁来研究外加磁 场对磁控溅射制备氮化硅陷光薄膜的影响. 通过X射线衍射、原子力显微镜 (AFM) 以及紫外分光光度计分别测试了外加磁场前后所制备薄膜的组织结构、表面形貌和光学性能. 结果表明, 外加磁场后, 氮化硅薄膜依然呈现非晶结构; 但是表面形貌发生明显改变, 中心磁场1.50 T下, 薄膜表面为特殊锥状尖峰结构"类金字塔"的突起, 而且这些突起颗粒垂直于基底表面; 在 可见光及近红外范围内, 中心磁场1.50 T 下的薄膜样品平均透射率最大, 平均透射率达到90% 以上, 比未加磁场的样品提高了近1 倍, 具有很好的陷光特性.
关键词:
外加磁场
磁控溅射
氮化硅薄膜
陷光效应 相似文献
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结合干涉光刻和磁控溅射制备了一维周期性起伏的磁性多层薄膜。利用扫描探针显微镜对样品的微结构进行表征,利用椭偏仪和磁光测量系统对样品的光学性能参数和磁光克尔效应进行测试和研究。实验结果发现,磁性多层薄膜磁光性能得到极大的提升,磁光增强的克尔谱峰值与条带的宽度、中间层二氧化铪层的厚度有关;利用介质层的厚度可调制复合薄膜的磁光特性。进一步研究发现横克尔效应的增强现象。理论计算的结果证实,磁光增强源于光学腔干涉共振和磁等离激元的耦合效应。 相似文献
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磁流体磁彻体力的两种简化形式Helmholtz力和Kelvin力具有一定的适用范围.在推导磁流体中的磁彻体力表达式基础上,分析Helmholtz力和Kelvin力在磁流体中的起源,得出两种形式的成立条件.计算结果表明:当磁流体磁导率与外磁场强度无关时,磁流体磁彻体力可由Helmholtz力表示;当磁流体中磁性颗粒的平均磁矩与磁流体比体积无关时,Kelvin力为磁彻体力的简化形式;在磁流体磁化系数与其密度成正比情况下,Helmholtz力可转换为Kelvin力.
关键词:
磁流体
磁彻体力
Helmholtz力
Kelvin力 相似文献
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研究了结构为 (FM/SiO2)3/Ag/(SiO2/FM)3 多层膜的巨磁阻抗(GMI)效应(这里的F M≡FeCuCrVSiB).多层膜采用射频溅射法沉积在单晶Si衬底上,沉积过程中,沿膜面长方 向施加约72kA/m的磁场,然后在不同的温度下对样品进行了退火处理.结果表明,该多层膜 样品即使在沉积态便具有相当好的软磁性能和GMI效应,在7MHz的频率下,最大纵向和横向 巨磁阻抗比分别为45%和44%.在230℃下经90min退火处理后的样品具有最佳的GMI效应,在85MHz的频率下,最大纵向和横向巨磁阻抗比分别达到251%和277%.与磁性层总厚度相同的FeCuCrVSiB/Ag/FeCuCrVSiB三层膜相比较,在这种多层结构中出现的GMI效应更强.
关键词:
多层膜
巨磁阻抗效应
趋肤效应
有效磁导率 相似文献
13.
Gareev K. G. Luchinin V. V. Sevost’yanov E. N. Testov I. O. Testov O. A. 《Technical Physics》2019,64(6):893-896
Technical Physics - The samples of water-based magnetic fluid, which contain Fe3O4–SiO2 particles with a spherical shape and sizes less than 100 nm, have been obtained. The method based on... 相似文献
14.
Hye Moon Lee Soon Gil Kim Isao Matsui Toru Iwaki Ferry Iskandar I. Wuled Lenggoro Kikuo Okuyama 《Journal of magnetism and magnetic materials》2007
The deposition monolayers of L10 FePt nanoparticles via an electrospraying method and the magnetic properties of the deposited film were studied. FePt nanoparticles in a size of around 2.5 nm in diameter, prepared by a liquid process, were used as a precursor. The size of the deposited particles can be controlled up to 35 nm by controlling the sprayed droplet size that is formed by adjusting the precursor concentration and the precursor flow rate. The droplets were heated in a tubular furnace at a temperature of up to 900 °C to remove all organic compounds and to transform the FePt particles from disordered face centered cubic to an ordered FCT phase. Finally, the particles were deposited in the form of a monolayer film on a silicon substrate by electrostatic force and characterized by scanning electron microscopy. The monolayer of particles was obtained by the high charge on particles obtained during the electrospraying process. The magnetic properties of the monolayer were investigated by magneto-optic Kerr effect measurements. Coercivity up to 650 Oe for a film consisting of 35 nm L10 FePt nanoparticles was observed after heat treatment at a temperature of 800 °C. 相似文献
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以表面磁光克尔原理为机理,测量薄膜材料的磁性参数,实验上求得了饱和状态下坡莫合金的克尔偏转角,并测出了其磁滞回线. 相似文献
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光子自旋霍尔效应类似于电子系统中的电子自旋霍尔效应, 是在折射率梯度和光子分别扮演的外场和自旋电子的角色下, 由自旋-轨道相互作用而产生的光子自旋分裂现象. 光子自旋霍尔效应为操控光子提供了新的途径, 同时也提供了一种精确测量相关物理效应的方法. 本文研究了磁光克尔效应中光子自旋分裂现象, 建立了磁光克尔旋转与光子自旋霍尔效应之间的定量关系, 并通过弱测量系统观测了磁场作用下铁膜表面的光子自旋分裂位移, 得到相应的磁光旋转角, 验证了我们所推导的理论预测. 本文的研究成果为精确测量磁光克尔系数和磁光克尔旋转角提供了一种新方法. 相似文献
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G. A. MÜller K. P. Lieb E. Carpene K. Zhang P. Schaaf J. Faupel H. U. Krebs 《Hyperfine Interactions》2004,158(1-4):137-143
Modifications of magnetic properties upon heavy-ion irradiation have been recently investigated for films of ferromagnetic 3d-elements (Fe, Ni, Co) and alloys (permendur, permalloy), in relation to changes of their microstructure. Here we report on Xe-ion irradiation of a highly textured iron film prepared via pulsed-laser deposition on a MgO(100) single crystal and containing a thin 57Fe marker layer for magnetic orientation Mössbauer spectroscopy (MOMS). We compare the results with those obtained for a polycrystalline Fe/Si(100) sample produced by electron evaporation and premagnetized before Xe-irradiation in a 300 Oe external field. Characterization of the samples also included magneto-optical Kerr effect (MOKE), Rutherford backscattering spectroscopy (RBS) and X-ray diffraction (XRD). 相似文献
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I. A. Kolmychek V. L. Krutyanskii A. Maziewski N. Tahir A. O. Adeyeye T. V. Murzina 《Physics of the Solid State》2016,58(11):2233-2236
The azimuthal anisotropy of the linear and nonlinear magnetooptical Kerr effect has been studied for a structure that is an ordered array with 420-nm-diameter pores in a 30-nm-thick permalloy film on a silicon substrate. The azimuthal anisotropy of the magnetooptical Kerr effect and the coercive force, corresponding to 4 m symmetry of a planar nanopore array, has been established experimentally. The measurements are accompanied with the numerical calculation of the anisotropic magnetization distribution in the structure at different orientations of the applied magnetic field. 相似文献
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C. A. Ballentine R. L. Fink J. Araya-Pochet J. L. Erskine 《Applied Physics A: Materials Science & Processing》1989,49(5):459-466
We describe magneto-optic Kerr effect studies of ultrathin Fe and Ni films on single crystal surfaces of Ag and Cu. Monolayer Fe films on Ag(100) exhibit the theoretically predicted spin-orbit anisotropy, but also yield some interesting discrepancies between behavior predicted by Kerr effect and by spin-polarized photoemission experiments. Layer-dependent studies of the magnetic moment of Ni on Ag(111) and Ag(100) suggest sp-d hybridization effects quench the first layer magnetic moment on Ag(111) but not on Ag(100). Temperature dependent studies of thin film magnetization obtained from Kerr effect measurements yield thickness dependent Curie temperatures, and critical exponents for several thin film systems. 相似文献
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J.S. Tsay H.W. Chang Y.L. Chiou K.T. Huang W.Y. Chan Y.D. Yao 《Journal of magnetism and magnetic materials》2006
Influences of oxygen exposure on the magnetic properties of Co/Ge(1 1 1) ultrathin films have been investigated by surface magneto-optic Kerr effect technique. As the oxygen exposure increases on Co/Ge(1 1 1) films, their magnetic properties could be modified. As an example for 15 ML Co/Ge(1 1 1) films, the coercivity increases from 730 to 920 Oe and the remanence Kerr intensity is reduced for 500 Langmuir (L) of oxygen exposure. Corresponding compositions analyzed by Auger electron spectroscopy measurement shows that the amount of oxygen on the surface layers increases with increasing the oxygen exposure time. Oxygen distributes on the topmost layers of the film. The adsorbed oxygen influences the electronic density of states of Co and results in the changes of the magnetic properties. Besides, the appearance of O/Co/Ge interface could modify the stress anisotropy, and as a result the coercivity of ultrathin Co/Ge(1 1 1) film is enhanced. 相似文献