磁敏二极管及其应用

一、概述磁敏二极管是继霍尔元件和磁敏电阻之后发展起来的一种新型磁电转换元件。它具有体积小、磁灵敏度高的优点,可以广泛应用于磁场检测、自动磁力探伤、工业自动化和电子技术等领域。     

一种新型的磁敏传感器

利用铁基纳米微晶材料的磁敏特性和LC反馈式振荡器的特性,设计制作了一种新型的磁敏传感器,并对其性能进行了测试,实验结果表明,该传感器具有良好的性能,可用作弱磁场探测、磁敏开关等.     

非晶镍铁磁敏薄膜的巨磁阻抗效应

采用异常电沉积法在厚度为60～80μm的铜基片上制备了非晶镍铁磁敏薄膜,厚度为25～30μm.非晶镍铁磁敏薄膜具有优异的软磁性能,感生的切向各向异性会使薄膜在切向方向上形成磁畴,在薄膜纵向的交流电流驱动下产生振荡,导致非晶薄膜的阻抗变化.在10kHz～1MHz范围内研究了复合NiFe/Cu/NiFe磁敏薄膜与单层NiFe薄膜的巨磁阻抗效应特性.频率为40kHz时,在饱和磁场下,巨磁阻抗变化率达到最大值30%,复合NiFe/Cu/NiFe磁敏薄膜比单层NiFe薄膜的具有更明显的巨磁阻抗效应.     

新型磁敏元件

西德 DODUCOKG 公司研制成功了一种新型磁敏元件。这种新型磁敏元件充分利用了韦冈德(Wiegand)效应,它由一根短的、外部绕有由绝缘铜线绕成的敏感线圈的金属丝构成。当韦冈德(wiegand)组件周期地置     

当前国家优先发展的高技术制造业方向

国家发展计划委员会和科学技术部会同有关部门、省市,经过组织有关专家研究,编制了《当前优先发展的高技术产业重点领域指南》。其中,高技术制造业项目如下： 新型传感器 近期产业化的重点是：性能好和技术先进的力敏、磁敏、光敏、热敏、湿敏、离子敏传感器及红外传感器和光纤传感器等,并逐步实现规模化生产。 智能化工业控制部件与执行机构 近期产业化的重点是：逐步形成配有相应硬、软件的智能型阀门定位器和电动执行机构及无纸记录仪等自动化仪表的规模化生产。 快速原型制造工艺及成套设备 近期产业化的重点是：向机电制造企业提供…     

尼龙帘线增强NR/SBR并用胶基磁敏橡胶的磁流变效应及其力学性能

由于可通过外加磁场来控制磁敏橡胶的刚度和强度,同时可解决磁流变液颗粒沉降、稳定性差的问题,因此磁敏橡胶成为国内外广泛关注的一种新型智能材料。制备了尼龙帘线增强型天然橡胶/丁苯橡胶(natural rubber/styrenebutadiene rubber,NR/SBR)并用胶基磁敏橡胶,采用Zwick/Roell电子拉力机和力磁耦合动态力学分析仪研究其静态力学性能和动态磁流变效应。结果表明,尼龙帘线的加入可以极大地提高磁敏橡胶的抗拉强度,同时也可提高磁敏橡胶的剪切模量和零场剪切储能模量;当加入三层帘线时,其抗拉强度可达到17.8 MPa,零场剪切储能模量为2.87 MPa;但随着尼龙帘线的增多,其磁流变效应则降低。     

我国将重点发展七大类新型元器件

根据有关部门制定的“突出重点、择优支持；上规模、上档次、争份额”发展战略，未来几年我国元器件产业将重点发展以个七大类新型产品：＿１．表而贴装元器件。重点发展片式陶瓷电容器、片式电阻器、片式二、三极管、片式错电容器和表面贴装用印刷电路板。２．厚膜混合集成电路（ＨＩＣ）。重点发展为程控交换机、汽车电子等投资类整机配套的产ＤＤＯ。３．敏感元器件及传感器。重点发展电压敏、热敏、气敏和磁敏产品。４．光电子器件。重点发展ＬＣＤ、ＬＥＣ芯片，ＬＤ和ＣＣＤ器件及ＶＦＤ、ＰＤＰ、ＦＥＤ等新一代显示器件。５·新型电…     

FCZ-1型非接触式转速表

一、引言本转速表系应用新型磁敏元件——强磁性金属薄膜磁敏电阻,利用其对磁场强度十分敏感的特点设计而成的转速测试仪,由于它的最大优点是采用非接触方式测量旋转物体的转速,因此它不受被测物启动力矩大小和被测物表面摩擦系数大小的影响,即不用考虑传感头和旋转体间摩擦力大小以及是否有滑动情况,避免了丢转。较之接触式转速表,其测量精度得到了提高。又由于磁敏电     

基于MSE/PVDF复合结构转速传感器的研究

磁敏弹性体(MSE)是一种具有优良磁响应特性的磁敏材料,在磁场作用下将产生垂直其表面的磁致法向力,结合聚偏氟乙烯(PVDF)的正压电效应,针对转速检测提出一种结合两者特性的转速传感器,在敏感单元中设计由MSE与PVDF压电单元组成复合结构,通过复合结构感知磁场激励以实现转速检测,并从微观与宏观层面分析了检测机理,采用自建测试系统确立了磁致法向力与磁场间的关系,PVDF的动态形变响应及传感器的输出特性。结果表明：以复合结构为核心的敏感单元对测试转速的磁场激励表现出稳定的电压峰值响应,并能够实现对中高转速的准确检测。     

新型集成三漏CMOS磁敏传感器

本文介绍了一种新型的集成三漏CMOS磁敏传感器的电路原理、电路特点及研制结果,该电路制作在0.9×0.9mm~2的芯片面积上。该器件具有以下优点:高磁灵敏度,良好的稳定性及温度特性、功能强、显示出良好的工程应用价值。     

A magnetic field direction meter

A magnetic field direction meter is described. The meter consists of a semiconductor magnetic-field sensitive double-collector transistor (magnetotransistor) with ferromagnetic concentrators of the magnetic field, differential amplifier, and digital voltmeter. The angular sensitivity of the magnetotransistor with concentrators to the Earth’s magnetic field is 0.2 mV/degree. The magnetotransistor and the amplifier are built as a single silicon chip.     

A Scanning Magnetooptical Micromagnetometer

A scanning magnetooptical magnetometer designed for measuring weak spatially nonuniform magnetic fields is described. The magnetometer's principle of operation is based on the Faraday effect caused by the magnetic field under study in the region of an epitaxial garnet-type ferrite film whose dimensions are on the order of the period of its domain structure. The magnetic-field sensitivity of the designed magnetometer is about 3 × 10⁻³ Oe for a spatial resolution of about 20 μm. __________ Translated from Pribory i Tekhnika Eksperimenta, No. 5, 2005, pp. 107–110. Original Russian Text Copyright ? 2005 by Vil'danov, Sokolov.     

A 10 tesla table-top controlled waveform magnet

Controlled waveform magnets (CWMs) are a class of pulsed magnets whose pulse shape with time can be programmed by the user. With a CWM, the user gains control not only over the magnitude of the field but also over its rate of change. In this work we present a table-top CWM, driven by a capacitor bank, capable of producing virtually any user-shaped magnetic field waveform up to 10 tesla. Insulated gate bipolar transistor chips have been paralleled to form the high current switch and paralleled chips of SiC Schottky diodes form the crowbar diode module. Sample controlled waveforms including flat-tops up to 10 tesla and some triangular magnetic field pulses have been successfully generated for 10-20 ms with a ripple <1%.     

V-shaped metal–oxide–semiconductor transistor probe with nano tip for surface electric properties

We design and fabricate a V-shaped metal–oxide–semiconductor (MOS) transistor probe with the focused-ion-beam (FIB) nano tip to measure surface electric properties. The V-shaped structure is selected for its better lateral stiffness, and the specific dimensions are determined using the parallel beam approximation (PBA). The deposition conditions for the nano tip are also investigated for better tip sharpness. The high working frequency of the MOS transistor improves the scanning speed and the high sensitivity reduces the additional equipment required. The detection properties of the device are investigated with PZT poling patterns. The measured results show well-defined patterns, promising that the device can detect surface electric properties with high sensitivity and high working frequency.     

V-shaped metal-oxide-semiconductor transistor probe with nano tip for surface electric properties

We design and fabricate a V-shaped metal-oxide-semiconductor (MOS) transistor probe with the focused-ion-beam (FIB) nano tip to measure surface electric properties. The V-shaped structure is selected for its better lateral stiffness, and the specific dimensions are determined using the parallel beam approximation (PBA). The deposition conditions for the nano tip are also investigated for better tip sharpness. The high working frequency of the MOS transistor improves the scanning speed and the high sensitivity reduces the additional equipment required. The detection properties of the device are investigated with PZT poling patterns. The measured results show well-defined patterns, promising that the device can detect surface electric properties with high sensitivity and high working frequency.     

晶体管基座立式包装机的研制

晶体管基座是晶体管的重要组件,均采用大量生产。其立式包装机,运用机、电、气一体化设计,整体结构采用接近开关和磁感应气缸取得信号,利用机械手装盒、卸盒自动化程度高,运行平稳,工作效率高,操作简单方便。     

Plasma enclosed in a magnetic field produced by flexible surface magnets

A homogeneous steady state plasma with a usable volume of approximately 200 l and with an electron temperature of 1-2 eV and a plasma density of approximately 10(9)-10(10) cm(-3) is produced in a discharge chamber the outside of whose walls is covered with flexible magnetic strips. This magnet arrangement can be built at a fraction of the cost of a conventional system using rigid surface magnets. The magnetic multipole field leads to an increase of the plasma density by one to two orders of magnitude and it is also found to cause trapping of high energy electrons originating from the discharge region.     

基于材料磁特性的结构疲劳损伤磁测方法研究

结构疲劳损伤测量和评估方法的研究是一个难点。由于疲劳损伤伴随材料磁特性的变化,且磁测法测量简单方便,所以利用材料磁特性测量和评估结构的疲劳损伤具有实际意义。以Q235钢为试件,通过构建疲劳损伤磁测试验平台,研究了循环应力下,基于磁滞回线的结构疲劳损伤磁测法。结果表明,疲劳损伤不同,磁滞回线也不同。提取磁滞回线的矫顽力H_c和剩磁B_r作为特征量进行分析,结果显示,试件失效前的疲劳过程大致分为两个阶段:首先是H_c和B_r的快速增大阶段,该阶段的H_c和B_r对疲劳损伤的灵敏度较高;然后是H_c和B_r的变化缓慢阶段,该阶段的H_c和B_r对疲劳损伤的灵敏度较低。最后分析了H_c和B_r与疲劳累积损伤D的变化关系,能够为结构疲劳损伤的定量评估及在线监测技术的研究提供基础。     

Magnetic measurements at pressures above 10 GPa in a miniature ceramic anvil cell for a superconducting quantum interference device magnetometer

A miniature ceramic anvil high pressure cell (mCAC) was earlier designed by us for magnetic measurements at pressures up to 7.6 GPa in a commercial superconducting quantum interference magnetometer [N. Tateiwa et al., Rev. Sci. Instrum. 82, 053906 (2011)]. Here, we describe methods to generate pressures above 10 GPa in the mCAC. The efficiency of the pressure generation is sharply improved when the Cu-Be gasket is sufficiently preindented. The maximum pressure for the 0.6 mm culet anvils is 12.6 GPa when the Cu-Be gasket is preindented from the initial thickness of 300-60 μm. The 0.5 mm culet anvils were also tested with a rhenium gasket. The maximum pressure attainable in the mCAC is about 13 GPa. The present cell was used to study YbCu(2)Si(2) which shows a pressure induced transition from the non-magnetic to magnetic phases at 8 GPa. We confirm a ferromagnetic transition from the dc magnetization measurement at high pressure. The mCAC can detect the ferromagnetic ordered state whose spontaneous magnetic moment is smaller than 1 μ(B) per unit cell. The high sensitivity for magnetic measurements in the mCAC may result from the simplicity of cell structure. The present study shows the availability of the mCAC for precise magnetic measurements at pressures above 10 GPa.     

高灵敏度感应式磁传感器的研究

大地电磁测深需要较宽频率范围的感应式磁传感器来探测大深度范围,然而,随着频率的降低磁传感器的感应电压也随之降低;高频段由于磁性材料在磁化时存在趋肤效应,导致磁芯的有效面积变小,因此,提高磁芯的有效导磁率以及磁芯材料的有效面积是扩展频带提高传感器灵敏度的主要手段.采用高电阻率叠片磁芯并且在磁芯两侧附加磁通收集器的办法增加有效面积和有效导磁率从而提高传感器的灵敏度.标定结果表明传感器频率范围是0.001 Hz～10 kHz,在频率小于1 Hz的范围内灵敏度为0.24 V/(nT·Hz),频率高于1 Hz时,为0.75 V/nT,能够满足大深度范围探测的需要.