Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508585
M. Ishikawa, M. Tsukahara, M. Yamada, Y. Saito, K. Hamaya
A spin metal-oxide-semiconductor field-effect transistor (spin-MOSFET) is one of the emerging devices for the low power consumption in silicon-based electronics from the viewpoint of logic-in-memory architectures [1]. To realize these kinds of spintronic applications, one of the main issues for realizing the spin-MOSFETs is an observation of the high magnetoresistance (MR) ratio obtained by two-terminal local measurements at room temperature [2]. Up to now, although there are lots of studies of the local MR effect through the silicon (Si) channels, the values of the MR ratio are less than 0.8 % at 100 K [3] and 0.03 % at room temperature [4]. In this paper, we show relatively large MR ratios at room temperature in Si $< 100 >$ lateral spin valves (LSVs) with a small size $(0.305 mu mathrm {m}^{2})$ cross section in the spin-transport layer. For comparison of the crystal orientation of the Si spin-transport layers, we prepared two kinds of LSVs along Si $< 100 >$ and Si $< 110 >$ with CoFe/MgO electrodes on phosphorus-doped $(n sim 1.3 times 10 ^{19}$ cm $^{-3})(100)$ textured Si on insulator (SOI) ($sim 61$ nm) layer, as shown in Fig. 1(a). An MgO (1.1 nm) tunnel barrier was deposited on the SOI spin-transport layer at 200 °C by electron beam evaporation. Then, a CoFe (10 nm) and a Ru capping layer were sputtered on top of it under a base pressure less than $5 times 10 ^{-7}$ Pa. The MgO and CoFe layers were epitaxially grown on the (100) textured SOI, where the (100)-textured MgO layer was grown on Si(100). Device fabrication methods are described in detail elsewhere.[5] We have checked that these resistivity and Hall mobility of the Si spin-transport layer were almost the same by evaluating from longitudinal resistivity and Hall-effect measurements for Si $ < 100 >$ and Si $ < 110 >$ Hall-bar devices. Figures 1(b) and 1(c) show four-terminal nonlocal Hanle-effect curves for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at a bias current of 0.5 mA at 20 K. These data mean that we can obtain reliable spin transport in Si layers in our LSVs, as shown in our previous work [5]. It should be noted that the magnitude of the spin signal, $vert Delta R_{NL}vert $, for Si $ < 100 >$ is approximately twice as large as that for Si $ < 110 >$. Although the detailed will be published elsewhere [6], it is inferred that this phenomenon is tentatively interpreted by the difference in the spin injection/detection efficiency associated with the valley structures of the conduction band in Si. We hereafter focus on the MR effect that is one of the most important points for realizing the spin-MOSFETs. Figures 2(a) and 2(b) display the two-terminal local-MR signals for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at 20 K. Here the bias current is 0.5 mA. It should be noted that the magnitude of the local-MR signals, $vert Delta R_{L}vert $, for Si $ < 100 >$ is also larger than that for Si $ < 110 >$. Irrespective of measurement schemes, we can find the
自旋金属氧化物半导体场效应晶体管(自旋mosfet)是从逻辑存储器架构的角度来看，是硅基电子器件中低功耗的新兴器件之一[1]。为了实现这些自旋电子应用，实现自旋mosfet的主要问题之一是在室温下通过双端局部测量获得高磁阻(MR)比的观察[2]。到目前为止，虽然有很多关于硅通道局部磁流变效应的研究，但磁流变比的数值都小于0.8 % at 100 K [3] and 0.03 % at room temperature [4]. In this paper, we show relatively large MR ratios at room temperature in Si $< 100 >$ lateral spin valves (LSVs) with a small size $(0.305 mu mathrm {m}^{2})$ cross section in the spin-transport layer. For comparison of the crystal orientation of the Si spin-transport layers, we prepared two kinds of LSVs along Si $< 100 >$ and Si $< 110 >$ with CoFe/MgO electrodes on phosphorus-doped $(n sim 1.3 times 10 ^{19}$ cm $^{-3})(100)$ textured Si on insulator (SOI) ($sim 61$ nm) layer, as shown in Fig. 1(a). An MgO (1.1 nm) tunnel barrier was deposited on the SOI spin-transport layer at 200 °C by electron beam evaporation. Then, a CoFe (10 nm) and a Ru capping layer were sputtered on top of it under a base pressure less than $5 times 10 ^{-7}$ Pa. The MgO and CoFe layers were epitaxially grown on the (100) textured SOI, where the (100)-textured MgO layer was grown on Si(100). Device fabrication methods are described in detail elsewhere.[5] We have checked that these resistivity and Hall mobility of the Si spin-transport layer were almost the same by evaluating from longitudinal resistivity and Hall-effect measurements for Si $ < 100 >$ and Si $ < 110 >$ Hall-bar devices. Figures 1(b) and 1(c) show four-terminal nonlocal Hanle-effect curves for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at a bias current of 0.5 mA at 20 K. These data mean that we can obtain reliable spin transport in Si layers in our LSVs, as shown in our previous work [5]. It should be noted that the magnitude of the spin signal, $vert Delta R_{NL}vert $, for Si $ < 100 >$ is approximately twice as large as that for Si $ < 110 >$. Although the detailed will be published elsewhere [6], it is inferred that this phenomenon is tentatively interpreted by the difference in the spin injection/detection efficiency associated with the valley structures of the conduction band in Si. We hereafter focus on the MR effect that is one of the most important points for realizing the spin-MOSFETs. Figures 2(a) and 2(b) display the two-terminal local-MR signals for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at 20 K. Here the bias current is 0.5 mA. It should be noted that the magnitude of the local-MR signals, $vert Delta R_{L}vert $, for Si $ < 100 >$ is also larger than that for Si $ < 110 >$. Irrespective of measurement schemes, we can find the large difference in the spin injection/detection efficiency between Si $ < 100 >$ and Si $ < 110 >$ LSVs. We can also observe this effect even at room temperature (303 K), as shown in Fig. 2(c) and 2(d). Thanks to the crystal orientation effect, a relatively large $vert Delta R_{L}vert $ of $2 Omega $, which is the largest $vert Delta R_{L}vert $ value reported so far, can be obtained. The estimated MR ratio is approximately 0.06 %
{"title":"Large local magnetoresistance at room temperature in Si<100> devices.","authors":"M. Ishikawa, M. Tsukahara, M. Yamada, Y. Saito, K. Hamaya","doi":"10.1109/INTMAG.2018.8508585","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508585","url":null,"abstract":"A spin metal-oxide-semiconductor field-effect transistor (spin-MOSFET) is one of the emerging devices for the low power consumption in silicon-based electronics from the viewpoint of logic-in-memory architectures [1]. To realize these kinds of spintronic applications, one of the main issues for realizing the spin-MOSFETs is an observation of the high magnetoresistance (MR) ratio obtained by two-terminal local measurements at room temperature [2]. Up to now, although there are lots of studies of the local MR effect through the silicon (Si) channels, the values of the MR ratio are less than 0.8 % at 100 K [3] and 0.03 % at room temperature [4]. In this paper, we show relatively large MR ratios at room temperature in Si $< 100 >$ lateral spin valves (LSVs) with a small size $(0.305 mu mathrm {m}^{2})$ cross section in the spin-transport layer. For comparison of the crystal orientation of the Si spin-transport layers, we prepared two kinds of LSVs along Si $< 100 >$ and Si $< 110 >$ with CoFe/MgO electrodes on phosphorus-doped $(n sim 1.3 times 10 ^{19}$ cm $^{-3})(100)$ textured Si on insulator (SOI) ($sim 61$ nm) layer, as shown in Fig. 1(a). An MgO (1.1 nm) tunnel barrier was deposited on the SOI spin-transport layer at 200 °C by electron beam evaporation. Then, a CoFe (10 nm) and a Ru capping layer were sputtered on top of it under a base pressure less than $5 times 10 ^{-7}$ Pa. The MgO and CoFe layers were epitaxially grown on the (100) textured SOI, where the (100)-textured MgO layer was grown on Si(100). Device fabrication methods are described in detail elsewhere.[5] We have checked that these resistivity and Hall mobility of the Si spin-transport layer were almost the same by evaluating from longitudinal resistivity and Hall-effect measurements for Si $ < 100 >$ and Si $ < 110 >$ Hall-bar devices. Figures 1(b) and 1(c) show four-terminal nonlocal Hanle-effect curves for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at a bias current of 0.5 mA at 20 K. These data mean that we can obtain reliable spin transport in Si layers in our LSVs, as shown in our previous work [5]. It should be noted that the magnitude of the spin signal, $vert Delta R_{NL}vert $, for Si $ < 100 >$ is approximately twice as large as that for Si $ < 110 >$. Although the detailed will be published elsewhere [6], it is inferred that this phenomenon is tentatively interpreted by the difference in the spin injection/detection efficiency associated with the valley structures of the conduction band in Si. We hereafter focus on the MR effect that is one of the most important points for realizing the spin-MOSFETs. Figures 2(a) and 2(b) display the two-terminal local-MR signals for Si $ < 100 >$ and Si $ < 110 >$ LSVs, respectively, at 20 K. Here the bias current is 0.5 mA. It should be noted that the magnitude of the local-MR signals, $vert Delta R_{L}vert $, for Si $ < 100 >$ is also larger than that for Si $ < 110 >$. Irrespective of measurement schemes, we can find the ","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"42 9","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91437334","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508118
Shoushou Zhang, Siyuan Guo
The subdomain model for analytical calculation of magnetic field is widely developed to predict electromagnetic performance in permanent magnet (PM) machines. Based on the principle of the mutual flux through the stator windings due to step-skewed PMs identical to that from equivalent non-skewed (PM), a 2D subdomain model of surface-mounted PM machines accounting for step-skewed magnets is proposed. By resolving the analytical expressions of the equivalent PMs subdomain, the 3D problem of step-skewed magnets along axis is simplified to a 2D problem, which saves the computational resources and improves the efficiency. The 2D multislice finite-element analysis confirms accuracy of the analytical method.
{"title":"2D Analytical Subdomain Model of Surface-Mounted PM Machines Accounting for Step-skewed Magnets","authors":"Shoushou Zhang, Siyuan Guo","doi":"10.1109/INTMAG.2018.8508118","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508118","url":null,"abstract":"The subdomain model for analytical calculation of magnetic field is widely developed to predict electromagnetic performance in permanent magnet (PM) machines. Based on the principle of the mutual flux through the stator windings due to step-skewed PMs identical to that from equivalent non-skewed (PM), a 2D subdomain model of surface-mounted PM machines accounting for step-skewed magnets is proposed. By resolving the analytical expressions of the equivalent PMs subdomain, the 3D problem of step-skewed magnets along axis is simplified to a 2D problem, which saves the computational resources and improves the efficiency. The 2D multislice finite-element analysis confirms accuracy of the analytical method.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"2 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80233991","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508039
N. Imaoka, S. Yamamoto, K. Ozaki
We report the synthesis and characterization of a high-magnetization Fe-Mn powder that is easily solidified using conventional powder-metallurgy processes rather than the conventional method of using rolled electrical steel sheets. Fe-Mn powders doped with 0.1 and 33 at% manganese, referred to as “Mn0.1” and “Mn33”, respectively, were fabricated by the reduction of Mn-doped-ferrite (Fe1−xMnx)3O4 nanopowders with hydrogen gas at 900–1100 °C. The starting manganese-doped-ferrite nanopowder, with particles in the 5–50 nm size range, were prepared using an aqueous process. The Mn0.1 sample exhibited a saturation magnetization of ~219 emu/g, which is comparable to that of pure iron powders. The Mn0.1 and Mn33 powders, featuring crystal sizes of 0.1–10 μm, exhibited coercivities of 0.1–1 Oe; these values are much lower than that of similarly sized iron powders. To study the fine microstructures of these powders, transmission electron microscopy augmented with energy-dispersive X-ray spectroscopy was used, which revealed grains 20–100 nm in size, despite the Mn0.1 and Mn33 specimens having different manganese contents. As these sizes are rather large for coercivity to be controlled by random anisotropy, we propose that a novel magnetic-reversal mechanism operates in these Fe-Mn powders.
{"title":"Magnetic Properties and Microstructures of Newly Developed Iron-Based Soft Magnetic Powders","authors":"N. Imaoka, S. Yamamoto, K. Ozaki","doi":"10.1109/INTMAG.2018.8508039","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508039","url":null,"abstract":"We report the synthesis and characterization of a high-magnetization Fe-Mn powder that is easily solidified using conventional powder-metallurgy processes rather than the conventional method of using rolled electrical steel sheets. Fe-Mn powders doped with 0.1 and 33 at% manganese, referred to as “Mn0.1” and “Mn33”, respectively, were fabricated by the reduction of Mn-doped-ferrite (Fe1−xMnx)3O4 nanopowders with hydrogen gas at 900–1100 °C. The starting manganese-doped-ferrite nanopowder, with particles in the 5–50 nm size range, were prepared using an aqueous process. The Mn0.1 sample exhibited a saturation magnetization of ~219 emu/g, which is comparable to that of pure iron powders. The Mn0.1 and Mn33 powders, featuring crystal sizes of 0.1–10 μm, exhibited coercivities of 0.1–1 Oe; these values are much lower than that of similarly sized iron powders. To study the fine microstructures of these powders, transmission electron microscopy augmented with energy-dispersive X-ray spectroscopy was used, which revealed grains 20–100 nm in size, despite the Mn0.1 and Mn33 specimens having different manganese contents. As these sizes are rather large for coercivity to be controlled by random anisotropy, we propose that a novel magnetic-reversal mechanism operates in these Fe-Mn powders.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"36 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76016743","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508440
H. Kawano, H. Oshima, K. Shimizu, A. Furuya, Y. Uehara, J. Kato, M. Kitaoka, Kazuyoshi Hakamata
This paper presents accurate simulation of the magnetic properties of manganese-zinc (Mn-Zn) ferrite toroidal cores using the dimensional resonance effect. We prepared as-sintered Mn-Zn ferrite toroidal cores with systematically varied dimensions and precisely measured their complex permeability and loss at frequencies of up to several MHz. We also performed magnetic simulation for core models with real shapes by combining the finite element method with an equivalent circuit model that describes the capacitive behavior at high-resistive grain boundaries in polycrystalline Mn-Zn ferrite. We showed that the systematic variation of permeability according to the core size observed in the experiment was in good agreement with the simulation, from which we confirmed accurate prediction of the dimensional resonance effect. We also revealed that the frequency dependence of core loss in the experiment was well reproduced by the magnetic simulation.
{"title":"Systematic Experimental and Simulation Studies of Dimensional Resonance in Mn-Zn Ferrite Toroidal Cores","authors":"H. Kawano, H. Oshima, K. Shimizu, A. Furuya, Y. Uehara, J. Kato, M. Kitaoka, Kazuyoshi Hakamata","doi":"10.1109/INTMAG.2018.8508440","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508440","url":null,"abstract":"This paper presents accurate simulation of the magnetic properties of manganese-zinc (Mn-Zn) ferrite toroidal cores using the dimensional resonance effect. We prepared as-sintered Mn-Zn ferrite toroidal cores with systematically varied dimensions and precisely measured their complex permeability and loss at frequencies of up to several MHz. We also performed magnetic simulation for core models with real shapes by combining the finite element method with an equivalent circuit model that describes the capacitive behavior at high-resistive grain boundaries in polycrystalline Mn-Zn ferrite. We showed that the systematic variation of permeability according to the core size observed in the experiment was in good agreement with the simulation, from which we confirmed accurate prediction of the dimensional resonance effect. We also revealed that the frequency dependence of core loss in the experiment was well reproduced by the magnetic simulation.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"13 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73324525","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508753
G. Lei, Y. Guo, J. Zhu
Soft magnetic composite (SMC) material has been investigated for the development of cores for permanent magnet (PM) motors in recent years. Compared with the cores made of traditional silicon steel sheet, there are several special properties of SMC cores, including (1) the isotropic performance in electromagnetic and thermal properties due to the powder nature of SMC, making it ideal for the PM motors with 3D flux path, such as transverse flux machine (TFM) and claw pole motor (CPM); (2) the lower eddy current loss and magnetic permeability because of the isolation coat of the particles, the easier manufacturing ability of stator/rotor cores by using molding technology [1]–[3]. On the other hand, there are two main challenges for the manufacturing and application of SMC cores in PM motors. First, heat treatment is a crucial process in the manufacturing of SMC cores. There are several control parameters in this step such as the burn-off and curing temperatures and times. They will determine the core loss and magnetic permeability of the manufactured SMC cores. Therefore, optimal manufacturing factors should be investigated to obtain the best magnetic properties of the cores. Second, there are some manufacturing variations of the SMC cores like core densities and dimension, which will lead variations of the motor performances, such as output power and efficiency. Thus, the quality of the manufactured SMC cores will affect the quality of the SMC motors. To gain the best performances and good quality of the SMC cores and motors, manufacturing uncertainty analysis should be investigated for both SMC cores and motors. This work will consider these two challenges by using the Taguchi method. The Taguchi method is a robust design method with consideration of manufacturing variations and other noise factors in the manufacturing and usage of a product like motor. It is a structured approach for determining the best combination of inputs to produce a product or service, based on the orthogonal design technology and quality loss functions (or S/N ratio). It is one of the most powerful methods available to reduce product cost, improve quality, and simultaneously reduce development interval [4]–[6] [4]–[6]. In this work, this method will first be used for the determination of the best parameters for the heat treatment of SMC cores, and some manufacturing variations will be discussed. Then, to decrease the effects of manufacturing variations of SMC cores on the motor performances, this method will be investigated again to find out the best dimension of a 3D TFM to increase the manufacturing quality of the motor. 1. Determination of the best heat treatment parameters of SMC cores Fig. 1 illustrates several manufacturing facilities and samples for a 3D TFM with SMC cores. The hydraulic compact machine (Fig.1(c)) uses the die tools (Figs.1(a) &(b)) to compact the SMC powders to produce the raw SMC core (Fig.1(e)), then the high-temperature furnace will cook the ra
{"title":"Manufacturing Condition and Variations of Soft Magnetic Composite Cores for Application in PM Motors Based on Taguchi Method.","authors":"G. Lei, Y. Guo, J. Zhu","doi":"10.1109/INTMAG.2018.8508753","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508753","url":null,"abstract":"Soft magnetic composite (SMC) material has been investigated for the development of cores for permanent magnet (PM) motors in recent years. Compared with the cores made of traditional silicon steel sheet, there are several special properties of SMC cores, including (1) the isotropic performance in electromagnetic and thermal properties due to the powder nature of SMC, making it ideal for the PM motors with 3D flux path, such as transverse flux machine (TFM) and claw pole motor (CPM); (2) the lower eddy current loss and magnetic permeability because of the isolation coat of the particles, the easier manufacturing ability of stator/rotor cores by using molding technology [1]–[3]. On the other hand, there are two main challenges for the manufacturing and application of SMC cores in PM motors. First, heat treatment is a crucial process in the manufacturing of SMC cores. There are several control parameters in this step such as the burn-off and curing temperatures and times. They will determine the core loss and magnetic permeability of the manufactured SMC cores. Therefore, optimal manufacturing factors should be investigated to obtain the best magnetic properties of the cores. Second, there are some manufacturing variations of the SMC cores like core densities and dimension, which will lead variations of the motor performances, such as output power and efficiency. Thus, the quality of the manufactured SMC cores will affect the quality of the SMC motors. To gain the best performances and good quality of the SMC cores and motors, manufacturing uncertainty analysis should be investigated for both SMC cores and motors. This work will consider these two challenges by using the Taguchi method. The Taguchi method is a robust design method with consideration of manufacturing variations and other noise factors in the manufacturing and usage of a product like motor. It is a structured approach for determining the best combination of inputs to produce a product or service, based on the orthogonal design technology and quality loss functions (or S/N ratio). It is one of the most powerful methods available to reduce product cost, improve quality, and simultaneously reduce development interval [4]–[6] [4]–[6]. In this work, this method will first be used for the determination of the best parameters for the heat treatment of SMC cores, and some manufacturing variations will be discussed. Then, to decrease the effects of manufacturing variations of SMC cores on the motor performances, this method will be investigated again to find out the best dimension of a 3D TFM to increase the manufacturing quality of the motor. 1. Determination of the best heat treatment parameters of SMC cores Fig. 1 illustrates several manufacturing facilities and samples for a 3D TFM with SMC cores. The hydraulic compact machine (Fig.1(c)) uses the die tools (Figs.1(a) &(b)) to compact the SMC powders to produce the raw SMC core (Fig.1(e)), then the high-temperature furnace will cook the ra","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"30 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78034403","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508178
C. Falub, R. Hida, M. Meduňa, M. Bless, J. Richter, H. Rohrmann, T. Nadig, M. Padrun
Miniaturization of the RF passive devices and DC-DC converters is key to achieving lighter, faster and more efficient mobile devices, and high-conversion ratio DC micro-grids, as the 5th generation (5G) wireless network and Internet of Things (IoT) paradigms emerge. In order to realize this objective, however, the biggest challenge remains shrinking the size of the chip-integrated magnetic components (e.g., micro-inductors, micro-transformers). Due to their flux amplification properties and high operating frequencies, integrated thin film magnetic cores with high permeability based on amorphous and polycrystalline magnetic alloys promise further device miniaturization, lower energy loss and thus lower power operation [1], [2]. Yet, integrating these magnetic films on the silicon complementary metal oxide semiconductors (Si-CMOS) platform is technologically very challenging, since for a significant inductance enhancement, several-micrometer-thick films with ultra-low losses need to be deposited. Moreover, leveraging this gain requires complex tailoring of the device architecture and magnetic thin film properties, since maximizing simultaneously the inductance, frequency bandwidth and peak quality factor is very difficult [3]. In this work, we present an economical method of manufacturing magnetic thin films, which allows combining soft magnetic materials with complementary properties, e.g., high saturation magnetization, low coercivity, high specific resistivity and low magnetostriction. Soft magnetic multilayered thin films based on the Ni78.5Fe21.5, Co91.5Ta4.5Zr4, Fe52Co28B20, Fe65Co35 alloy materials were deposited on 8” bare Si and Si/200nm-thermal-SiO2 wafers in an industrial, high-throughput Evatec LLS EVO II magnetron sputtering system [4]. The sputtered multilayers consisted of stacks of alternating 80nm-thick ferromagnetic layers and 4nm-thick Al2O3 dielectric interlayers. Since the substrate cage rotates continuously, such that the substrates face different targets (e.g., NiFe, FeCoB, CoTaZr) alternatively (Fig. 1a), each ferromagnetic sublayer in the multilayer stack can exhibit a nano-layered structure with very sharp interfaces as revealed by X-ray reflectometry (XRR) and transmission electron microscopy (TEM) (Fig. 1b,c). We adjusted the thickness of these individual nanolayers by changing the cage rotation speed and the power of each cathode, which is an excellent mode to engineer new, composite ferromagnetic materials with tunable properties. The ferromagnetic layers were deposited by DC sputtering at a pressure of $1.7 times 10 ^{-3}$ mbar using Ni-21.5%Fe, Fe-28%Co-20%B (at.%) and Co-4.5%Ta-4%Zr long life (~250 kWh) targets, whereas the dielectric Al2 O3 interlayers were deposited by RF sputtering from monoblock Al2 O3 targets at a pressure of $5 times 10 ^{-3}$ mbar. We introduced the in-plane magnetic anisotropy in these multilayered thin films during sputtering by a linear magnetic field parallel to the wafer plane, which is
{"title":"Nanostructured Soft Magnetic Multilayers with Tunable Properties for On-Chip Micro-Magnetic Devices.","authors":"C. Falub, R. Hida, M. Meduňa, M. Bless, J. Richter, H. Rohrmann, T. Nadig, M. Padrun","doi":"10.1109/INTMAG.2018.8508178","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508178","url":null,"abstract":"Miniaturization of the RF passive devices and DC-DC converters is key to achieving lighter, faster and more efficient mobile devices, and high-conversion ratio DC micro-grids, as the 5th generation (5G) wireless network and Internet of Things (IoT) paradigms emerge. In order to realize this objective, however, the biggest challenge remains shrinking the size of the chip-integrated magnetic components (e.g., micro-inductors, micro-transformers). Due to their flux amplification properties and high operating frequencies, integrated thin film magnetic cores with high permeability based on amorphous and polycrystalline magnetic alloys promise further device miniaturization, lower energy loss and thus lower power operation [1], [2]. Yet, integrating these magnetic films on the silicon complementary metal oxide semiconductors (Si-CMOS) platform is technologically very challenging, since for a significant inductance enhancement, several-micrometer-thick films with ultra-low losses need to be deposited. Moreover, leveraging this gain requires complex tailoring of the device architecture and magnetic thin film properties, since maximizing simultaneously the inductance, frequency bandwidth and peak quality factor is very difficult [3]. In this work, we present an economical method of manufacturing magnetic thin films, which allows combining soft magnetic materials with complementary properties, e.g., high saturation magnetization, low coercivity, high specific resistivity and low magnetostriction. Soft magnetic multilayered thin films based on the Ni78.5Fe21.5, Co91.5Ta4.5Zr4, Fe52Co28B20, Fe65Co35 alloy materials were deposited on 8” bare Si and Si/200nm-thermal-SiO2 wafers in an industrial, high-throughput Evatec LLS EVO II magnetron sputtering system [4]. The sputtered multilayers consisted of stacks of alternating 80nm-thick ferromagnetic layers and 4nm-thick Al2O3 dielectric interlayers. Since the substrate cage rotates continuously, such that the substrates face different targets (e.g., NiFe, FeCoB, CoTaZr) alternatively (Fig. 1a), each ferromagnetic sublayer in the multilayer stack can exhibit a nano-layered structure with very sharp interfaces as revealed by X-ray reflectometry (XRR) and transmission electron microscopy (TEM) (Fig. 1b,c). We adjusted the thickness of these individual nanolayers by changing the cage rotation speed and the power of each cathode, which is an excellent mode to engineer new, composite ferromagnetic materials with tunable properties. The ferromagnetic layers were deposited by DC sputtering at a pressure of $1.7 times 10 ^{-3}$ mbar using Ni-21.5%Fe, Fe-28%Co-20%B (at.%) and Co-4.5%Ta-4%Zr long life (~250 kWh) targets, whereas the dielectric Al2 O3 interlayers were deposited by RF sputtering from monoblock Al2 O3 targets at a pressure of $5 times 10 ^{-3}$ mbar. We introduced the in-plane magnetic anisotropy in these multilayered thin films during sputtering by a linear magnetic field parallel to the wafer plane, which is ","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"28 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80384970","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508707
Q. Syed, I. Hahn
Recently, great interest is developing towards axial flux permanent magnet motor (AFPM) for direct-driven in-wheel applications, due to their inherent multipolar disc-type structure and small axial length. Three-disc AFPMs have a high torque density because they effectively utilize the intermediate disc and are compact enough to be easily mounted in the wheel. Mechanical problems are also reduced because an intermediate disc is equally attracted in axial direction by its both sides. The slotted double stator and single rotor (DSSR) AFPM has more power and torque density and less cost, weight, volume, inertia and cooling problems in comparison to the single stator and double rotor (SSDR) AFPM topologies [1]. The flux focusing type slotted DSSR AFPM consumes a less amount of the permanent magnets (PMs) and has more torque density compared to the surface mounted permanent magnet (SPM) type slotted DSSR AFPM [2]. Therefore, in this paper flux focusing type DSSR AFPM is further investigated for parametric optimization. Initial dimensions of the flux focusing type DSSR AFPM are selected using the basic analytical modelling. A 3D finite element analysis (FEA) is utilized for its detailed characteristic analysis. The flux focusing type DSSR AFPM has 24 number of poles and 36 number of stator slots on each stator disc. Although it has a less winding factor (0.866), which decreases the output electromagnetic torque, it has a less total harmonic distortion (THD), zero fundamental or 1st harmonic, which reduces the losses, especially core losses. Due to the symmetry and its high periodicity of 12, 1/24th of each geometrical model of the flux focusing type DSSR AFPM is analysed using a 3D FEA, which decreases the computation time. The design of experiments (DoE) method is used for the parametric optimization of the flux focusing type DSSR AFPM. Although it is time-consuming due to the 3D FEA, it is suitable for the electromagnetic optimization of motor [3]. Initially, the full factorial design (FFD) is applied to analyse the effect of different design variables on the performance of the flux focusing type DSSR AFPM. With the help of the FFD, the significant design parameters can be identified easily. The FFD is very time-consuming, therefore, only the minimum, maximum and mean values of each design variable are considered, which limits the DoE. To extend the DoE and also to reduce the computation time compared to the FFD, the Latin hypercube sampling method (LHS) is used for the detailed characteristic analysis of the flux focusing type DSSR AFPM. The objective is to get best motor performance, such as high electromagnetic torque and back EMF and low torque ripple, cogging torque and total harmonic distortion (THD). The flux focussing type DSSR AFPM has constant outer radius length, current density, airgap, and stator yoke height. The design variables of the flux focussing type DSSR AFPM are shown in Fig. 1, where “A” is the ratio of the stator slot width and
{"title":"Parametric Optimization of Flux Focusing Type Double Stator and Single Rotor Axial Flux Permanent Magnet Motor.","authors":"Q. Syed, I. Hahn","doi":"10.1109/INTMAG.2018.8508707","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508707","url":null,"abstract":"Recently, great interest is developing towards axial flux permanent magnet motor (AFPM) for direct-driven in-wheel applications, due to their inherent multipolar disc-type structure and small axial length. Three-disc AFPMs have a high torque density because they effectively utilize the intermediate disc and are compact enough to be easily mounted in the wheel. Mechanical problems are also reduced because an intermediate disc is equally attracted in axial direction by its both sides. The slotted double stator and single rotor (DSSR) AFPM has more power and torque density and less cost, weight, volume, inertia and cooling problems in comparison to the single stator and double rotor (SSDR) AFPM topologies [1]. The flux focusing type slotted DSSR AFPM consumes a less amount of the permanent magnets (PMs) and has more torque density compared to the surface mounted permanent magnet (SPM) type slotted DSSR AFPM [2]. Therefore, in this paper flux focusing type DSSR AFPM is further investigated for parametric optimization. Initial dimensions of the flux focusing type DSSR AFPM are selected using the basic analytical modelling. A 3D finite element analysis (FEA) is utilized for its detailed characteristic analysis. The flux focusing type DSSR AFPM has 24 number of poles and 36 number of stator slots on each stator disc. Although it has a less winding factor (0.866), which decreases the output electromagnetic torque, it has a less total harmonic distortion (THD), zero fundamental or 1st harmonic, which reduces the losses, especially core losses. Due to the symmetry and its high periodicity of 12, 1/24th of each geometrical model of the flux focusing type DSSR AFPM is analysed using a 3D FEA, which decreases the computation time. The design of experiments (DoE) method is used for the parametric optimization of the flux focusing type DSSR AFPM. Although it is time-consuming due to the 3D FEA, it is suitable for the electromagnetic optimization of motor [3]. Initially, the full factorial design (FFD) is applied to analyse the effect of different design variables on the performance of the flux focusing type DSSR AFPM. With the help of the FFD, the significant design parameters can be identified easily. The FFD is very time-consuming, therefore, only the minimum, maximum and mean values of each design variable are considered, which limits the DoE. To extend the DoE and also to reduce the computation time compared to the FFD, the Latin hypercube sampling method (LHS) is used for the detailed characteristic analysis of the flux focusing type DSSR AFPM. The objective is to get best motor performance, such as high electromagnetic torque and back EMF and low torque ripple, cogging torque and total harmonic distortion (THD). The flux focussing type DSSR AFPM has constant outer radius length, current density, airgap, and stator yoke height. The design variables of the flux focussing type DSSR AFPM are shown in Fig. 1, where “A” is the ratio of the stator slot width and","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"145 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76242385","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508359
B. Schauerte, S. Steentjes, N. Leuning, K. Hameyer
Increasing rotating frequencies of electrical machines to maximize the power density lead to higher tensile and compressive mechanical stresses that are distributed inhomogeneously along the rotors’ cross section and add up to the already present residual stresses induced by the preceding manufacturing and processing steps. These effects are either neglected or considered only in the post-processing of the machine layout and design.Neglecting the mechanical impact on the magnetic properties during numerical machine simulations leads to uncertainties and deviations from the actual material behavior. This deviations are transmitted to the subsequent loss calculation and further post-processing resulting in inaccurate loss maps. In this paper the influence of mechanical stress on the hysteresis properties and occurring losses of a non-oriented soft magnetic material are examined and replicated by an adjusted energy-based hysteresis model. The chosen models ability to recreate the observed behavior for both, anhysteretic and hysteretic components, will then be evaluated. The evaluation of the model will be performed with focus on a variety of characteristic magnetic properties. Namely the required maximum magnetic field, measured and simulated losses and the ability of the model, to recreate the actual measured magnetic flux paths including the remanence polarisation and coercive magnetic field.
{"title":"A continuous parameter-based approach to model the effect of mechanical stress on the electromagnetic hysteresis characteristic","authors":"B. Schauerte, S. Steentjes, N. Leuning, K. Hameyer","doi":"10.1109/INTMAG.2018.8508359","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508359","url":null,"abstract":"Increasing rotating frequencies of electrical machines to maximize the power density lead to higher tensile and compressive mechanical stresses that are distributed inhomogeneously along the rotors’ cross section and add up to the already present residual stresses induced by the preceding manufacturing and processing steps. These effects are either neglected or considered only in the post-processing of the machine layout and design.Neglecting the mechanical impact on the magnetic properties during numerical machine simulations leads to uncertainties and deviations from the actual material behavior. This deviations are transmitted to the subsequent loss calculation and further post-processing resulting in inaccurate loss maps. In this paper the influence of mechanical stress on the hysteresis properties and occurring losses of a non-oriented soft magnetic material are examined and replicated by an adjusted energy-based hysteresis model. The chosen models ability to recreate the observed behavior for both, anhysteretic and hysteretic components, will then be evaluated. The evaluation of the model will be performed with focus on a variety of characteristic magnetic properties. Namely the required maximum magnetic field, measured and simulated losses and the ability of the model, to recreate the actual measured magnetic flux paths including the remanence polarisation and coercive magnetic field.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"8 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75231452","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508363
B. Rameshti, S. Sharma, Y. Blanter, G. Bauer
The interaction between magnon and photons in cavities has attracted much attention in the past few years. The material of choice is the electrically insulating ferrimagnetic insulator yttrium iron garnet with exceptional high magnetic quality. The interest has, on one hand, been focused on (infrared) light scattering in monolithic YIG spheres that act as spherical optical resonators. On the other hand, both YIG spheres and films have been loaded into microwave cavities, from which the magnetization dynamics could be read-out by microwave transmission/reflection spectra or, electrically, with heavy metal contacts. In this talk I will report our theoretical efforts to understand experimental results and predict new effects in both research areas, both published [1–4] and unpublished.
{"title":"Magnons in Photonic Cavities and Resonators","authors":"B. Rameshti, S. Sharma, Y. Blanter, G. Bauer","doi":"10.1109/INTMAG.2018.8508363","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508363","url":null,"abstract":"The interaction between magnon and photons in cavities has attracted much attention in the past few years. The material of choice is the electrically insulating ferrimagnetic insulator yttrium iron garnet with exceptional high magnetic quality. The interest has, on one hand, been focused on (infrared) light scattering in monolithic YIG spheres that act as spherical optical resonators. On the other hand, both YIG spheres and films have been loaded into microwave cavities, from which the magnetization dynamics could be read-out by microwave transmission/reflection spectra or, electrically, with heavy metal contacts. In this talk I will report our theoretical efforts to understand experimental results and predict new effects in both research areas, both published [1–4] and unpublished.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"33 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78233386","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}
Pub Date : 2018-04-23DOI: 10.1109/INTMAG.2018.8508856
K. Mohri
The Magnetics research, technology, and industry has been rapidly shifted in these years to the field of micro magnetic sensors due to the world-wide competing production of micro geo-magnetic sensors installed in the electronic compasses for Smart phones and mobile phones with the production number of more than 1 billion per year since 2014.
{"title":"High-performance micro magnetic sensors installed in wearable electronic compasses and I-o-T magnetic sensors promoting new information society - Amorphous Wire CMOS IC Magneto- Impedance Sensors -.","authors":"K. Mohri","doi":"10.1109/INTMAG.2018.8508856","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508856","url":null,"abstract":"The Magnetics research, technology, and industry has been rapidly shifted in these years to the field of micro magnetic sensors due to the world-wide competing production of micro geo-magnetic sensors installed in the electronic compasses for Smart phones and mobile phones with the production number of more than 1 billion per year since 2014.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"71 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78720361","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}
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