首页 > 最新文献

2015 IEEE Magnetics Conference (INTERMAG)最新文献

英文 中文
Stability study of spin torque oscillator for microwave assisted magnetic recording (MAMR) 微波辅助磁记录(MAMR)用自旋力矩振荡器稳定性研究
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157098
T. Zhou, M. Zhang, Z. Yuan
MAMR is one of the technologies which could push recording density up to 3-4 Tb/in2 [1-4]. The center part of MAMR is the spin torque oscillator (STO) for the generation of localized ac magnetic field in the microwave frequency regime of 20-30 GHz[5-6]. The STO is placed between the main pole and the trailing shield (Fig. 1a), where a strong magnetic field (gap field) exists. The gap field acts on the STO and greatly affects its performance [7]. Due to very low flying height of 2-3 nm, the STO also senses the field from recording media (Fig. 1a). The media field roughly lies in the magnetization-precession plane of the free layer (field generation layer or FGL) (Fig. 1b), which alters the FGL energy landscape and therefore disturbs its precession, causing STO instability. This is one of the key concerns for MAMR. Using micromagnetic simulation, we studied the STO stability against the gap field and the media stray field. It is found that the Ku of the reference layer, the gap field and the media stray field have a big effect on the STO stability. Possible approaches to enhancing the STO stability are proposed.
MAMR是可以将记录密度提高到3-4 Tb/in2的技术之一[1-4]。MAMR的中心部分是自旋力矩振荡器(STO),用于在20-30 GHz微波频率范围内产生局域交流磁场[5-6]。STO位于主极和尾屏蔽之间(图1a),存在强磁场(间隙场)。间隙场作用于STO上,对其性能影响很大[7]。由于飞行高度非常低,只有2-3纳米,STO还可以从记录介质中感知磁场(图1a)。介质场大致位于自由层(场生成层或FGL)的磁化进动面(图1b),它改变了FGL的能量格局,从而扰乱了其进动,导致STO不稳定。这是MAMR的主要关注点之一。利用微磁仿真技术,研究了STO在间隙场和介质杂散场作用下的稳定性。研究发现,参考层的Ku、间隙场和介质杂散场对STO的稳定性有较大影响。提出了提高STO稳定性的可行方法。
{"title":"Stability study of spin torque oscillator for microwave assisted magnetic recording (MAMR)","authors":"T. Zhou, M. Zhang, Z. Yuan","doi":"10.1109/INTMAG.2015.7157098","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157098","url":null,"abstract":"MAMR is one of the technologies which could push recording density up to 3-4 Tb/in2 [1-4]. The center part of MAMR is the spin torque oscillator (STO) for the generation of localized ac magnetic field in the microwave frequency regime of 20-30 GHz[5-6]. The STO is placed between the main pole and the trailing shield (Fig. 1a), where a strong magnetic field (gap field) exists. The gap field acts on the STO and greatly affects its performance [7]. Due to very low flying height of 2-3 nm, the STO also senses the field from recording media (Fig. 1a). The media field roughly lies in the magnetization-precession plane of the free layer (field generation layer or FGL) (Fig. 1b), which alters the FGL energy landscape and therefore disturbs its precession, causing STO instability. This is one of the key concerns for MAMR. Using micromagnetic simulation, we studied the STO stability against the gap field and the media stray field. It is found that the Ku of the reference layer, the gap field and the media stray field have a big effect on the STO stability. Possible approaches to enhancing the STO stability are proposed.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121060915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Harmonic and magnetic charge model comparison of spherical permanent magnet structures considering a neumann boundary 考虑诺伊曼边界的球形永磁结构的谐波和磁荷模型比较
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157114
B. V. Ninhuijs, J. Jansen, B. Gysen, Elena A. Lomonova
The rapid advances in assistive devices brought out the desire of spherical actuators because of their multiple degrees of freedom and similarity to ball and socket joints [1]. For this application a high torque density is beneficial for the volume of these devices. Due to the typical structure of slotted spherical actuators, designs have to be modeled in 3-D to gain accurate results. As commercially available modeling tools, such as FEA (finite element analysis), are very time consuming, semi-analytical models are needed to optimize a design. A slotted topology can be evaluated by including a Neumann boundary, representing material with a high permeability and a surface current density sheet distribution to model the coils [2]. Two semi-analytical models exists for obtaining the magnetic flux density generated by a spherical permanent magnet array namely, harmonic model [3] and magnetic charge model [4].
随着辅助装置的快速发展,球面执行器具有多个自由度,且与球关节和窝关节相似[1]。对于这种应用,高扭矩密度有利于这些设备的体积。由于开槽球形作动器的典型结构,设计必须进行三维建模才能获得准确的结果。由于商业上可用的建模工具,如FEA(有限元分析)非常耗时,因此需要半解析模型来优化设计。狭缝拓扑可以通过包含诺伊曼边界来评估,诺伊曼边界表示具有高磁导率的材料和表面电流密度片分布来模拟线圈[2]。球形永磁阵列产生的磁通密度有两种半解析模型,即谐波模型[3]和磁荷模型[4]。
{"title":"Harmonic and magnetic charge model comparison of spherical permanent magnet structures considering a neumann boundary","authors":"B. V. Ninhuijs, J. Jansen, B. Gysen, Elena A. Lomonova","doi":"10.1109/INTMAG.2015.7157114","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157114","url":null,"abstract":"The rapid advances in assistive devices brought out the desire of spherical actuators because of their multiple degrees of freedom and similarity to ball and socket joints [1]. For this application a high torque density is beneficial for the volume of these devices. Due to the typical structure of slotted spherical actuators, designs have to be modeled in 3-D to gain accurate results. As commercially available modeling tools, such as FEA (finite element analysis), are very time consuming, semi-analytical models are needed to optimize a design. A slotted topology can be evaluated by including a Neumann boundary, representing material with a high permeability and a surface current density sheet distribution to model the coils [2]. Two semi-analytical models exists for obtaining the magnetic flux density generated by a spherical permanent magnet array namely, harmonic model [3] and magnetic charge model [4].","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"04 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127258886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A novel analytical model of air-gap permeance in tubular linear switched reluctance actuators with hybrid flux paths 具有混合磁通路径的管状线性开关磁阻执行器气隙磁通分析模型
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7156546
X. Xue, K. Cheng, Y. Bao, Z. Zhang
Due to simple and robust configuration, and without any coils and magnets on movers, a tubular linear switched reluctance actuator (TLSRA) is a promising candidate for applications of frequently reciprocating linear motion, such as linear compressors and automotive active suspension systems. For air-gap in a TLSRA, there are the longitudinal and transverse magnetic paths due to various mover positions. Change in air-gap permeance in a TLSRA results in the thrust force, which drives the mover for linear motion. Thus, the air-gap permeance is the crucial parameter for computing the thrust force in the electromagnetic design and estimating the real-time thrust force in force control of TLSRAs. In general, the air-gap permeance at two special positions can be calculated analytically, such as the maximum and minimum air-gap permeance. It is a challenging issue that an analytically model is developed to compute the air-gap permeance at arbitrary mover positions. This paper focuses on that permeance model development.
由于结构简单且坚固耐用,并且在驱动器上没有任何线圈和磁铁,管状线性开关磁阻执行器(TLSRA)是频繁往复线性运动应用的有希望的候选者,例如线性压缩机和汽车主动悬架系统。对于TLSRA中的气隙,由于不同的移动位置,存在纵向和横向磁路。在TLSRA中,气隙渗透率的变化导致推力的产生,推力驱动动器进行直线运动。因此,气隙磁导率是电磁设计中计算推力和力控制中实时估计推力的关键参数。一般情况下,两个特殊位置的气隙渗透率可以解析计算,如最大气隙渗透率和最小气隙渗透率。如何建立一个解析模型来计算任意动器位置的气隙渗透率是一个具有挑战性的问题。本文重点研究了该渗透模型的发展。
{"title":"A novel analytical model of air-gap permeance in tubular linear switched reluctance actuators with hybrid flux paths","authors":"X. Xue, K. Cheng, Y. Bao, Z. Zhang","doi":"10.1109/INTMAG.2015.7156546","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7156546","url":null,"abstract":"Due to simple and robust configuration, and without any coils and magnets on movers, a tubular linear switched reluctance actuator (TLSRA) is a promising candidate for applications of frequently reciprocating linear motion, such as linear compressors and automotive active suspension systems. For air-gap in a TLSRA, there are the longitudinal and transverse magnetic paths due to various mover positions. Change in air-gap permeance in a TLSRA results in the thrust force, which drives the mover for linear motion. Thus, the air-gap permeance is the crucial parameter for computing the thrust force in the electromagnetic design and estimating the real-time thrust force in force control of TLSRAs. In general, the air-gap permeance at two special positions can be calculated analytically, such as the maximum and minimum air-gap permeance. It is a challenging issue that an analytically model is developed to compute the air-gap permeance at arbitrary mover positions. This paper focuses on that permeance model development.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"2018 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125182256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Tayloring the hysteresis loop of soft magnetic nanocrystalline alloys by magnetic and tensile stress annealing 采用磁退火和拉应力退火对软磁纳米晶合金的磁滞回线进行泰勒化
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157083
L. Varga
The eddy current limits for metallic cores should be shifted above 1 MHz in order to keep the operating frequencies about 100 to 500 kHz for inductors and transformers. The high operating frequency permits the mass and volume reducing which is a major demand nowadays in aerospace and automobile applications. Specially, in the context of aerospace applications, a magnetic material that can maintain a lower core loss over the applicable temperature range can provide a basis for nosing out the competition with ferrites (limited temperature range) and with crystalline permalloy of 17 μm thick (limited plastic yields strength). It has been recognized that for low loss and wide applicable temperature demand magnetic field and stress annealed Finemet represent an advanced material permitting new solutions for high frequency magnetics. Compact toroids without gap can be prepared with high quality factor and high current inductors. This work presents some new results concerning the magnetic field and stress annealing.
为了使电感器和变压器的工作频率保持在100至500千赫左右,金属铁芯的涡流限制应移至1兆赫以上。高工作频率允许减少质量和体积,这是当今航空航天和汽车应用的主要需求。特别是,在航空航天应用的背景下,一种能够在适用温度范围内保持较低铁芯损耗的磁性材料可以为与铁氧体(有限温度范围)和17 μm厚的晶莫合金(有限塑性屈服强度)的竞争提供基础。人们已经认识到,对于低损耗和广泛适用的温度要求,磁场和应力退火的Finemet代表了一种先进的材料,为高频磁性提供了新的解决方案。采用高质量因数和高电流电感可以制备无间隙紧凑的环形电路。本文提出了一些关于磁场和应力退火的新结果。
{"title":"Tayloring the hysteresis loop of soft magnetic nanocrystalline alloys by magnetic and tensile stress annealing","authors":"L. Varga","doi":"10.1109/INTMAG.2015.7157083","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157083","url":null,"abstract":"The eddy current limits for metallic cores should be shifted above 1 MHz in order to keep the operating frequencies about 100 to 500 kHz for inductors and transformers. The high operating frequency permits the mass and volume reducing which is a major demand nowadays in aerospace and automobile applications. Specially, in the context of aerospace applications, a magnetic material that can maintain a lower core loss over the applicable temperature range can provide a basis for nosing out the competition with ferrites (limited temperature range) and with crystalline permalloy of 17 μm thick (limited plastic yields strength). It has been recognized that for low loss and wide applicable temperature demand magnetic field and stress annealed Finemet represent an advanced material permitting new solutions for high frequency magnetics. Compact toroids without gap can be prepared with high quality factor and high current inductors. This work presents some new results concerning the magnetic field and stress annealing.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126079010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Magnetocaloric and hysteretic properties of Ni-Mn based Heusler alloys Ni-Mn基Heusler合金的磁热和磁滞特性
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157274
T. Gottschall, K. Skokov, E. Palacios, R. Burriel, O. Gutfleisch
The aim of this work is the comprehensive characterization of the magnetocaloric effect of Heusler alloys using different measurement techniques like calorimetry, magnetometry and the direct determination of the adiabatic temperature change in order to combine them in the S(T) diagram. It turns out that some discrepancies can appear when comparing measurements obtained with different speeds.
这项工作的目的是利用不同的测量技术,如量热法、磁强计和绝热温度变化的直接测定,全面表征Heusler合金的磁热效应,以便将它们结合在S(T)图中。事实证明,在比较以不同速度获得的测量结果时,可能会出现一些差异。
{"title":"Magnetocaloric and hysteretic properties of Ni-Mn based Heusler alloys","authors":"T. Gottschall, K. Skokov, E. Palacios, R. Burriel, O. Gutfleisch","doi":"10.1109/INTMAG.2015.7157274","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157274","url":null,"abstract":"The aim of this work is the comprehensive characterization of the magnetocaloric effect of Heusler alloys using different measurement techniques like calorimetry, magnetometry and the direct determination of the adiabatic temperature change in order to combine them in the S(T) diagram. It turns out that some discrepancies can appear when comparing measurements obtained with different speeds.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126166046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Development of high sensitivity multi core MI element 高灵敏度多芯MI元件的研制
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7156660
N. Hamada, A. Shimode, C. Cai, M. Yamamoto
MI sensor is a magnetic sensor based on the Magneto Impedance (MI) effect discovered by Mori et al. in 1993[1]. A small and highly sensitive magnetic sensor (AMI 306) based on above MI effect and used as an electromagnetic compass mainly in mobile phones and smart phones has been developed and commercialized by AICHI MICRO INTELLIGENT[2]. According to theoretical analysis, the MI sensor is foreseen to show the fT/√Hz level of noise density[3], and its performance would even be equal to SQUID. MI element (AMI306) with pickup coil fabricated by a plating process is used in electromagnetic compasses. Although it shows magnetic resolution in the micro Tesla order[4], higher performance in sensitivity and noise level is required.
MI传感器是Mori等人在1993年[1]发现的基于磁阻抗(Magneto Impedance, MI)效应的磁传感器。爱知微智基于上述磁敏效应开发了一种小型高灵敏度磁敏传感器(AMI 306),主要用于手机和智能手机的电磁罗盘,并已实现商业化[2]。根据理论分析,预计MI传感器的噪声密度将达到fT/√Hz水平[3],其性能甚至可以与SQUID媲美。采用电镀工艺制造带拾取线圈的MI元件(AMI306)用于电磁罗盘。虽然显示了微特斯拉量级的磁分辨率[4],但对灵敏度和噪声水平的要求更高。
{"title":"Development of high sensitivity multi core MI element","authors":"N. Hamada, A. Shimode, C. Cai, M. Yamamoto","doi":"10.1109/INTMAG.2015.7156660","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7156660","url":null,"abstract":"MI sensor is a magnetic sensor based on the Magneto Impedance (MI) effect discovered by Mori et al. in 1993[1]. A small and highly sensitive magnetic sensor (AMI 306) based on above MI effect and used as an electromagnetic compass mainly in mobile phones and smart phones has been developed and commercialized by AICHI MICRO INTELLIGENT[2]. According to theoretical analysis, the MI sensor is foreseen to show the fT/√Hz level of noise density[3], and its performance would even be equal to SQUID. MI element (AMI306) with pickup coil fabricated by a plating process is used in electromagnetic compasses. Although it shows magnetic resolution in the micro Tesla order[4], higher performance in sensitivity and noise level is required.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115066024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Radio-frequency (RF) fly height monitoring system for Heat-Assisted Magnetic Recording (HAMR) 用于热辅助磁记录(HAMR)的射频(RF)飞行高度监测系统
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157660
L. Franca-Neto, B. Knigge, K. Flechsig, K. Hunter
In HDDs, during write operation, the transducer head flies over the media with no continuous monitoring on the adequacy of its flying height against sudden incidents. If the head hits an asperity or a lubricant spill drops from the head, the head momentarily oscillates around its intended fly height. This can compromise the data being written. Only by issuing a read command can the drive evaluate the quality of the data just written. This verification after write is not normally performed because it impacts drive performance. Heat-Assisted Magnetic Recording (HAMR) holds promises for higher data densities in magnetic media into the future and an “always-on” fly height monitoring system is desired. In HAMR, maintaining adequate fly height during write operation is a requirement from both the magnetic writing and the near-field heating antenna operation. The Radio-Frequency (RF) based system described in this work for fly height monitoring is non-magnetic in nature and, since the gap between head and media is smaller than the mean distance between air molecules, this system is also immune to temperature changes in the head or in the ambient. As shown in figure 1, the air gap between the flying head and the media is represented in electrical domain by capacitors (C1 and C2 in fig. 1). An RF signal of frequency significantly above the frequencies taken by the data signal's spectrum (cf. fig. 1) is injected onto the write lines. This RF signal capacitively couples onto all the elements on the head and the head-media interface (cf. fig. 1). When the head changes its fly height, the corresponding capacitance for the air gap changes its value. This varying capacitance behaves as a charge pump, which amplitude modulates (AM) the RF signal and injects this AM-modulated RF signal back into the head wiring. This signal travels back through the suspension and is detected at the pre-amplifier end. The amplitude of the sidebands carry information on fly height changes. The closer the head flies to the media, the stronger the AM sideband tones for the same disturbance in fly height.
在hdd中,在写入操作期间,换能器头在介质上飞行,没有连续监测其飞行高度是否足以应对突发事件。如果头部碰到一个尖锐的物体或润滑剂从头部溢出,头部会暂时围绕其预定的飞行高度摆动。这可能危及正在写入的数据。只有发出读命令,驱动器才能评估刚刚写入的数据的质量。写入后的验证通常不执行,因为它会影响驱动器性能。热辅助磁记录(HAMR)有望在未来的磁性介质中实现更高的数据密度,并且需要一个“永远在线”的飞行高度监测系统。在HAMR中,在写入操作期间保持足够的飞行高度是磁写入和近场加热天线操作的要求。本研究中描述的基于射频(RF)的飞行高度监测系统本质上是非磁性的,由于头部和介质之间的距离小于空气分子之间的平均距离,因此该系统也不受头部或环境温度变化的影响。如图1所示,飞头和介质之间的气隙在电域中由电容器(图1中的C1和C2)表示。将频率明显高于数据信号频谱所取频率的射频信号(参见图1)注入写入线路。该射频信号电容耦合到磁头和磁头-介质接口上的所有元件上(参见图1)。当磁头改变其飞行高度时,气隙对应的电容值也会改变。这种变化的电容表现为电荷泵,它对射频信号进行幅度调制(AM),并将这种AM调制的射频信号注入头部接线。该信号通过悬架返回,并在前置放大器端检测到。边带的振幅携带飞行高度变化的信息。头部飞得越近媒体,在飞行高度相同的扰动中,AM边带音调越强。
{"title":"Radio-frequency (RF) fly height monitoring system for Heat-Assisted Magnetic Recording (HAMR)","authors":"L. Franca-Neto, B. Knigge, K. Flechsig, K. Hunter","doi":"10.1109/INTMAG.2015.7157660","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157660","url":null,"abstract":"In HDDs, during write operation, the transducer head flies over the media with no continuous monitoring on the adequacy of its flying height against sudden incidents. If the head hits an asperity or a lubricant spill drops from the head, the head momentarily oscillates around its intended fly height. This can compromise the data being written. Only by issuing a read command can the drive evaluate the quality of the data just written. This verification after write is not normally performed because it impacts drive performance. Heat-Assisted Magnetic Recording (HAMR) holds promises for higher data densities in magnetic media into the future and an “always-on” fly height monitoring system is desired. In HAMR, maintaining adequate fly height during write operation is a requirement from both the magnetic writing and the near-field heating antenna operation. The Radio-Frequency (RF) based system described in this work for fly height monitoring is non-magnetic in nature and, since the gap between head and media is smaller than the mean distance between air molecules, this system is also immune to temperature changes in the head or in the ambient. As shown in figure 1, the air gap between the flying head and the media is represented in electrical domain by capacitors (C1 and C2 in fig. 1). An RF signal of frequency significantly above the frequencies taken by the data signal's spectrum (cf. fig. 1) is injected onto the write lines. This RF signal capacitively couples onto all the elements on the head and the head-media interface (cf. fig. 1). When the head changes its fly height, the corresponding capacitance for the air gap changes its value. This varying capacitance behaves as a charge pump, which amplitude modulates (AM) the RF signal and injects this AM-modulated RF signal back into the head wiring. This signal travels back through the suspension and is detected at the pre-amplifier end. The amplitude of the sidebands carry information on fly height changes. The closer the head flies to the media, the stronger the AM sideband tones for the same disturbance in fly height.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115179298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Preparation of Fe-based soft magnetic composites with high Bs by acidic bluing coating 酸性蓝涂法制备高硼铁基软磁复合材料
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157714
G. Zhao, C. Wu, M. Yan
Fe-based soft magnetic composites (SMCs) are technologically important due to their unique properties such as satisfactory magnetic performance and low loss for high frequency applications. Insulation coating of the ferromagnetic powders is critical in the preparation of SMCs. While traditional phosphate treatment allows surface passivation of the Fe powders, the obtained phosphate coating layers are non-magnetic, resulting in decreased saturation magnetization. Consequently, it is essential to develop SMCs with both high flux density and low loss. In this work, acidic bluing method has been used to grow Fe3O4 layers as insulation coating on the surfaces of iron powders. As Fe3O4 is a ferromagnetic material with high electrical resistivity, the effect of magnetic dilution can be avoided.
铁基软磁复合材料(SMCs)由于其独特的性能,如令人满意的磁性和低损耗,在高频应用中具有重要的技术意义。铁磁粉末的绝缘涂层是制备SMCs的关键。而传统的磷酸盐处理允许铁粉的表面钝化,得到的磷酸盐涂层是无磁性的,导致降低饱和磁化。因此,开发高磁通密度和低损耗的SMCs至关重要。本研究采用酸性发蓝法在铁粉表面生长Fe3O4层作为绝缘涂层。由于Fe3O4是一种具有高电阻率的铁磁性材料,可以避免磁稀释的影响。
{"title":"Preparation of Fe-based soft magnetic composites with high Bs by acidic bluing coating","authors":"G. Zhao, C. Wu, M. Yan","doi":"10.1109/INTMAG.2015.7157714","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157714","url":null,"abstract":"Fe-based soft magnetic composites (SMCs) are technologically important due to their unique properties such as satisfactory magnetic performance and low loss for high frequency applications. Insulation coating of the ferromagnetic powders is critical in the preparation of SMCs. While traditional phosphate treatment allows surface passivation of the Fe powders, the obtained phosphate coating layers are non-magnetic, resulting in decreased saturation magnetization. Consequently, it is essential to develop SMCs with both high flux density and low loss. In this work, acidic bluing method has been used to grow Fe3O4 layers as insulation coating on the surfaces of iron powders. As Fe3O4 is a ferromagnetic material with high electrical resistivity, the effect of magnetic dilution can be avoided.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115489621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of air-gap between metal strips and a ferrite plate on magnetic shielding 金属条与铁氧体板间气隙对磁屏蔽的影响
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157202
H. Park, J. Kwon, S. Kwak, S. Ahn
In this paper, the effect of air-gap between the metal strip and ferrite plate on magnetic shielding in the presence of a periodic line current source is analyzed in two-dimensional and approximate model of the WPT coils in electric vehicles and mobile devices. An analytical method based on Fourier transform and mode matching technique is proposed to investigate the penetration of quasistatic magnetic field into the ferrite plate and metal strips.
本文以电动汽车和移动设备中WPT线圈为研究对象,分析了周期性线电流源存在时,金属带与铁氧体极板之间的气隙对磁屏蔽的影响。提出了一种基于傅里叶变换和模式匹配技术的准静态磁场穿透铁氧体板和金属条的分析方法。
{"title":"Effect of air-gap between metal strips and a ferrite plate on magnetic shielding","authors":"H. Park, J. Kwon, S. Kwak, S. Ahn","doi":"10.1109/INTMAG.2015.7157202","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157202","url":null,"abstract":"In this paper, the effect of air-gap between the metal strip and ferrite plate on magnetic shielding in the presence of a periodic line current source is analyzed in two-dimensional and approximate model of the WPT coils in electric vehicles and mobile devices. An analytical method based on Fourier transform and mode matching technique is proposed to investigate the penetration of quasistatic magnetic field into the ferrite plate and metal strips.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116060919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Analytical expressions for transition width and transition jitter in granular PMR media taking account of switching field distribution 考虑开关场分布的颗粒状PMR介质中过渡宽度和过渡抖动的解析表达式
Pub Date : 2015-05-11 DOI: 10.1109/INTMAG.2015.7157321
T. Jin, H. Muraoka, S. Greaves
We have reported analytical expressions for transition width and transition jitter based on the media micro-structure and the readback resolution. In most practical applications, the switching field distribution (SFD) cannot be ignored. In this work we derive analytical formulations that are good approximations for the transition width and transition jitter using Voronoi cell modeling with a finite SFD.
我们报道了基于介质微观结构和读回分辨率的过渡宽度和过渡抖动的解析表达式。在大多数实际应用中,开关场分布(SFD)是不可忽视的。在这项工作中,我们使用有限SFD的Voronoi细胞建模,推导出了很好的近似过渡宽度和过渡抖动的解析公式。
{"title":"Analytical expressions for transition width and transition jitter in granular PMR media taking account of switching field distribution","authors":"T. Jin, H. Muraoka, S. Greaves","doi":"10.1109/INTMAG.2015.7157321","DOIUrl":"https://doi.org/10.1109/INTMAG.2015.7157321","url":null,"abstract":"We have reported analytical expressions for transition width and transition jitter based on the media micro-structure and the readback resolution. In most practical applications, the switching field distribution (SFD) cannot be ignored. In this work we derive analytical formulations that are good approximations for the transition width and transition jitter using Voronoi cell modeling with a finite SFD.","PeriodicalId":381832,"journal":{"name":"2015 IEEE Magnetics Conference (INTERMAG)","volume":"990 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116227978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
2015 IEEE Magnetics Conference (INTERMAG)
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1