Magnetic materials with low magnetic loss are required to realize both a high-frequency support and a miniaturization of radio frequency components. Hexagonal close-packed cobalt (hcp-Co) nanoparticles are considered suitable for high frequencies due to their nanoparticle morphology and high magnetocrystalline anisotropy. However, the face-centered cubic (fcc) or the ϵ phase with low magnetocrystalline anisotropy is fabricated in the synthetization of Co nanoparticles with a size of less than a few hundred nanometers. In this letter, we investigate the synthesis of Co nanoparticles by the thermolysis of dicobalt octacarbonyl at various temperatures for obtaining Co particles with a single hcp phase. Although Co nanoparticles synthesized at 453 K exhibited a mixture of hcp and fcc phases with an hcp phase ratio of 25%, Co nanoparticles almost achieved the hcp phase ratio of 100% by decreasing the thermolysis temperature to 333 K or lower. Furthermore, we evaluated the permeability spectrum of the composite with Co particles of 10 vol% dispersed in polystyrene. Although the real part of the permeability in the composite containing Co nanoparticles with the mixed phase of fcc and hcp monotonously decreased with frequency, the composite contained Co nanoparticles with a single phase with a suitable constant value up to 3 GHz for high-frequency applications.
{"title":"Synthesis of Hexagonal Close-Packed Cobalt Nanoparticles From Thermolysis of Cobalt Carbonyl","authors":"Kyohei Takahashi;Hiroshi Ito;Isao Kanada;Hiroyuki Matsumoto","doi":"10.1109/LMAG.2023.3316608","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3316608","url":null,"abstract":"Magnetic materials with low magnetic loss are required to realize both a high-frequency support and a miniaturization of radio frequency components. Hexagonal close-packed cobalt (hcp-Co) nanoparticles are considered suitable for high frequencies due to their nanoparticle morphology and high magnetocrystalline anisotropy. However, the face-centered cubic (fcc) or the ϵ phase with low magnetocrystalline anisotropy is fabricated in the synthetization of Co nanoparticles with a size of less than a few hundred nanometers. In this letter, we investigate the synthesis of Co nanoparticles by the thermolysis of dicobalt octacarbonyl at various temperatures for obtaining Co particles with a single hcp phase. Although Co nanoparticles synthesized at 453 K exhibited a mixture of hcp and fcc phases with an hcp phase ratio of 25%, Co nanoparticles almost achieved the hcp phase ratio of 100% by decreasing the thermolysis temperature to 333 K or lower. Furthermore, we evaluated the permeability spectrum of the composite with Co particles of 10 vol% dispersed in polystyrene. Although the real part of the permeability in the composite containing Co nanoparticles with the mixed phase of fcc and hcp monotonously decreased with frequency, the composite contained Co nanoparticles with a single phase with a suitable constant value up to 3 GHz for high-frequency applications.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-4"},"PeriodicalIF":1.2,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67763015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This letter presents an innovative method for rapid and precise measurement of bacteria in liquid samples for point-of-care testing. The method utilizes the bacteria concentration-dependent ac susceptibility of magnetic nanoparticles, allowing for efficient and practical bacterial detection. The ac susceptibility of the magnetic nanoparticles/bacteria aggregate exhibits a decrease proportional to the bacteria concentration, attributed to the influence of bacteria on the magnetic coupling between the magnetic nanoparticles and magnetic dynamic response of the aggregate. To validate the performance of our method, we conducted measurements on Fusobacterium nucleatum samples obtained from both healthy individuals and cancer patients. The results demonstrated a robust correlation (correlation factor up to 0.94) between our measurements and the results obtained through quantitative polymerase chain reaction (qPCR) analysis, highlighting the high precision and accuracy of our method in quantifying bacteria, which is comparable to a qPCR system. The simplified apparatus not only reduces costs but also saves time by eliminating the need for DNA amplification of short segments, making it a promising alternative for rapid and precise bacterial measurement in point-of-care testing.
{"title":"Magnetic Susceptibility-Based Detection of Fusobacterium Nucleatum in Human Saliva","authors":"Kazuhiko Okita;Youcheng Pu;Loi Tonthat;Toru Murayama;Shin Yabukami;Yohei Ozawa;Seji Asamitsu;Hiroshi Okamoto;Takashi Kamei","doi":"10.1109/LMAG.2023.3308062","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3308062","url":null,"abstract":"This letter presents an innovative method for rapid and precise measurement of bacteria in liquid samples for point-of-care testing. The method utilizes the bacteria concentration-dependent ac susceptibility of magnetic nanoparticles, allowing for efficient and practical bacterial detection. The ac susceptibility of the magnetic nanoparticles/bacteria aggregate exhibits a decrease proportional to the bacteria concentration, attributed to the influence of bacteria on the magnetic coupling between the magnetic nanoparticles and magnetic dynamic response of the aggregate. To validate the performance of our method, we conducted measurements on \u0000<italic>Fusobacterium nucleatum</i>\u0000 samples obtained from both healthy individuals and cancer patients. The results demonstrated a robust correlation (correlation factor up to 0.94) between our measurements and the results obtained through quantitative polymerase chain reaction (qPCR) analysis, highlighting the high precision and accuracy of our method in quantifying bacteria, which is comparable to a qPCR system. The simplified apparatus not only reduces costs but also saves time by eliminating the need for DNA amplification of short segments, making it a promising alternative for rapid and precise bacterial measurement in point-of-care testing.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-4"},"PeriodicalIF":1.2,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67763007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-22DOI: 10.1109/LMAG.2023.3307296
Qiangxin Li;Jian Feng;Qi Xiao;Xiong Gao
The lowest order mode of a shear-horizontal electromagnetic acoustic transducer (EMAT) typically exhibits a low signal-to-noise ratio and poor spatial resolution in defect detection. To solve this issue, this letter presents a crack identification and location method based on dual-reception magnetic encoded spatial pulse compression technology. On the one hand, the method implements spatial pulse compression technology by adjusting the spatial distribution of the magnetic field to obtain a high amplitude and narrow pulse detection signal. On the other hand, this method multiplexes the excitation EMAT as a receiver through signal processing technology, so that the position of cracks can be more accurately judged by analyzing the signals of the dual EMATs. Most importantly, this method does not require additional EMAT and complex excitation equipment. Finally, a simulation model was built to verify the method. The simulation results show, that compared with the detection signal of the traditional method, the SNR is improved by over 1.1 dB, and the spatial resolution is improved by over 18%. Additionally, the method can effectively distinguish the crack defects on both sides of EMATs, and the localization accuracy exceeds 95%.
{"title":"A Method of Shear-Horizontal EMAT Based on Dual-Reception Magnetic Encoded Spatial Pulse Compression for Multiple Cracks Identification and Location","authors":"Qiangxin Li;Jian Feng;Qi Xiao;Xiong Gao","doi":"10.1109/LMAG.2023.3307296","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3307296","url":null,"abstract":"The lowest order mode of a shear-horizontal electromagnetic acoustic transducer (EMAT) typically exhibits a low signal-to-noise ratio and poor spatial resolution in defect detection. To solve this issue, this letter presents a crack identification and location method based on dual-reception magnetic encoded spatial pulse compression technology. On the one hand, the method implements spatial pulse compression technology by adjusting the spatial distribution of the magnetic field to obtain a high amplitude and narrow pulse detection signal. On the other hand, this method multiplexes the excitation EMAT as a receiver through signal processing technology, so that the position of cracks can be more accurately judged by analyzing the signals of the dual EMATs. Most importantly, this method does not require additional EMAT and complex excitation equipment. Finally, a simulation model was built to verify the method. The simulation results show, that compared with the detection signal of the traditional method, the SNR is improved by over 1.1 dB, and the spatial resolution is improved by over 18%. Additionally, the method can effectively distinguish the crack defects on both sides of EMATs, and the localization accuracy exceeds 95%.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67762114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-02DOI: 10.1109/LMAG.2023.3301384
Seyed Hassan Hadi Nemati;Nima Eslami;Mohammad Hossein Moaiyeri
The computing-in-memory (CiM) approach is a promising option for addressing the processor–memory data transfer bottleneck while performing data-intensive applications. In this letter, we present a novel CiM architecture based on spin-transfer torque magnetic random-access memory, which can work in computing and memory modes. In this letter, two spintronic devices are considered per cell to store the main data and its complement to address the reliability concerns during the read operation, which also provides a fascinating ability for performing reliable Boolean operations (all basic functions), binary/ternary content-addressable memory search operation, and multi-input majority function. Since the developed architecture can perform bitwise xnor operations in one cycle, a resistive-based accumulator has been designed to perform multi-input majority production to improve the structure for implementing fast and low-cost binary neural networks (BNNs). To this end, multiplication, accumulation, and passing through the activation function are accomplished in three cycles. The simulation result of exploiting the architecture in the BNN application indicates 86%–98% lower power-delay product than existing architectures.
{"title":"Computing in Memory Using Doubled STT-MRAM With the Application of Binarized Neural Networks","authors":"Seyed Hassan Hadi Nemati;Nima Eslami;Mohammad Hossein Moaiyeri","doi":"10.1109/LMAG.2023.3301384","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3301384","url":null,"abstract":"The computing-in-memory (CiM) approach is a promising option for addressing the processor–memory data transfer bottleneck while performing data-intensive applications. In this letter, we present a novel CiM architecture based on spin-transfer torque magnetic random-access memory, which can work in computing and memory modes. In this letter, two spintronic devices are considered per cell to store the main data and its complement to address the reliability concerns during the read operation, which also provides a fascinating ability for performing reliable Boolean operations (all basic functions), binary/ternary content-addressable memory search operation, and multi-input majority function. Since the developed architecture can perform bitwise \u0000<sc>xnor</small>\u0000 operations in one cycle, a resistive-based accumulator has been designed to perform multi-input majority production to improve the structure for implementing fast and low-cost binary neural networks (BNNs). To this end, multiplication, accumulation, and passing through the activation function are accomplished in three cycles. The simulation result of exploiting the architecture in the BNN application indicates 86%–98% lower power-delay product than existing architectures.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67919308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-13DOI: 10.1109/LMAG.2023.3295271
Sohom Bhattacharjee;Choon Sik Cho;Dong Sik Cho
Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation technique that is used to treat a variety of neurological disorders, including major depression. The development of the deep brain TMS coil for stimulating subcortical structures expands the use of TMS beyond the stimulation of superficial cortical targets. Deep brain stimulation may have beneficial effects on neurological disorders such as Parkinson's disease, post-traumatic stress disorder, and mild traumatic brain injury. Previous studies have shown that the cerebellum plays a very big role in behavior and motor planning. To stimulate the specific areas of the human brain, we require a TMS coil with precise focal abilities because the material, design, and position of a TMS coil play a significant role in adjusting the coil's focusing power. Therefore, we studied stimulation of the frontal brain and cerebellum with two different new coil designs positioned on different locations. A rare design of the TMS coil made with Litz wire was developed to enhance excitation focality in the brain and was compared with a traditional figure-of-eight (FOE) coil and double-cone coil. The finite-element simulation tool ANSYS Maxwell 3-D has been used to simulate and compare the magnetic field and electric field induced inside the model of the human brain. The coil studies are as follows: a FOE coil, an overlapped copper coil, and a Litz wire overlapped coil. This was followed by experimental validation which shows great agreement with the simulation results.
{"title":"Development of Overlapped Designed Coils for Transcranial Magnetic Stimulations","authors":"Sohom Bhattacharjee;Choon Sik Cho;Dong Sik Cho","doi":"10.1109/LMAG.2023.3295271","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3295271","url":null,"abstract":"Transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation technique that is used to treat a variety of neurological disorders, including major depression. The development of the deep brain TMS coil for stimulating subcortical structures expands the use of TMS beyond the stimulation of superficial cortical targets. Deep brain stimulation may have beneficial effects on neurological disorders such as Parkinson's disease, post-traumatic stress disorder, and mild traumatic brain injury. Previous studies have shown that the cerebellum plays a very big role in behavior and motor planning. To stimulate the specific areas of the human brain, we require a TMS coil with precise focal abilities because the material, design, and position of a TMS coil play a significant role in adjusting the coil's focusing power. Therefore, we studied stimulation of the frontal brain and cerebellum with two different new coil designs positioned on different locations. A rare design of the TMS coil made with Litz wire was developed to enhance excitation focality in the brain and was compared with a traditional figure-of-eight (FOE) coil and double-cone coil. The finite-element simulation tool ANSYS Maxwell 3-D has been used to simulate and compare the magnetic field and electric field induced inside the model of the human brain. The coil studies are as follows: a FOE coil, an overlapped copper coil, and a Litz wire overlapped coil. This was followed by experimental validation which shows great agreement with the simulation results.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67762070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this letter, we present a 1T1D1M-based (one transistor, one diode, and one magnetic tunnel junction) spin-orbit torque, magnetic random-access memory (SOT-MRAM) with multimode magnetization switching for high-density memory, ultrahigh-speed writing, and energy-efficient on-chip memory application. The conventional spin-transfer torque (STT)-MRAM or SOT-MRAM is limited by the unipolar (or bipolar) switching property and demands the utilization of a common channel with bidirectional write current, which not only brings about source degradation of the access transistor but also increases the energy consumption in the write operation. By introducing a Schottky diode, the 1T1D1SOT-MRAM cell based on ultrafast switching of multiple modes outperforms conventional MRAMs in terms of decoupling of current channels in different directions and high-density integration. Simulation results show that the MRAM achieves 82% and 100% reduction in bit-cell area compared with STT-MRAM and SOT-MRAM, respectively, and ∼3.3× improvement in write energy consumption in comparison with STT-MRAM.
{"title":"High-Density 1T1D1SOT-MRAM With Multimode Ultrahigh-Speed Magnetization Switching","authors":"Hao Zhang;Di Wang;Long Liu;Xuefeng Zhao;Huai Lin;Changqing Xie","doi":"10.1109/LMAG.2023.3293407","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3293407","url":null,"abstract":"In this letter, we present a 1T1D1M-based (one transistor, one diode, and one magnetic tunnel junction) spin-orbit torque, magnetic random-access memory (SOT-MRAM) with multimode magnetization switching for high-density memory, ultrahigh-speed writing, and energy-efficient on-chip memory application. The conventional spin-transfer torque (STT)-MRAM or SOT-MRAM is limited by the unipolar (or bipolar) switching property and demands the utilization of a common channel with bidirectional write current, which not only brings about source degradation of the access transistor but also increases the energy consumption in the write operation. By introducing a Schottky diode, the 1T1D1SOT-MRAM cell based on ultrafast switching of multiple modes outperforms conventional MRAMs in terms of decoupling of current channels in different directions and high-density integration. Simulation results show that the MRAM achieves 82% and 100% reduction in bit-cell area compared with STT-MRAM and SOT-MRAM, respectively, and ∼3.3× improvement in write energy consumption in comparison with STT-MRAM.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67763004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effects of uniform and static moderate magnetic fields (0–400 mT) on the membrane potential of nerve fibers in Metapenaeus ensis shrimps were investigated. The results showed that the magnetic field caused an increase in membrane potential, eventually reaching a static state, and that effects of short-term exposure were largely reversible. A nonlinear relationship between the percentage change in membrane potential ( V% ) and magnetic field induction was observed, where V% increased rapidly below an inflection point (around 200 mT) and slowed down thereafter. Hypotheses suggest that ion channels in the membrane have varying sensitivities to magnetic fields and presented the distribution of ion channel activation thresholds within the 0–400 mT range. The identification of the inflection point holds great practical value in the fields of magnetic field therapy, exposure limits, and magnetic shielding design.
{"title":"Effect of Moderate Static Magnetic Field on Membrane Potential of Abdominal Nerve Fiber in Metapenaeus Ensis","authors":"Siyuan Liu;Shupeng Liu;Yongyong Gong;Jinbo Chen;Hengyu Li;Zhizheng Wu;Ze Cui;Mei Liu;Jingtao Lei;Tao Wang","doi":"10.1109/LMAG.2023.3293391","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3293391","url":null,"abstract":"The effects of uniform and static moderate magnetic fields (0–400 mT) on the membrane potential of nerve fibers in \u0000<italic>Metapenaeus ensis</i>\u0000 shrimps were investigated. The results showed that the magnetic field caused an increase in membrane potential, eventually reaching a static state, and that effects of short-term exposure were largely reversible. A nonlinear relationship between the percentage change in membrane potential (\u0000<italic>V%</i>\u0000) and magnetic field induction was observed, where \u0000<italic>V%</i>\u0000 increased rapidly below an inflection point (around 200 mT) and slowed down thereafter. Hypotheses suggest that ion channels in the membrane have varying sensitivities to magnetic fields and presented the distribution of ion channel activation thresholds within the 0–400 mT range. The identification of the inflection point holds great practical value in the fields of magnetic field therapy, exposure limits, and magnetic shielding design.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67919307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-28DOI: 10.1109/LMAG.2023.3290534
Ke Liu;Hongsong Miao;Qiang Fu;Yuqi Pang;Yangyi Sui
Aeromagnetic gradient tensor measurement has become a powerful method in geological surveys, mineral resource exploration, and other applications due to its ability to resist temporal changes of the geomagnetic field and its ability to provide rich information and be highly efficient. Various factors may affect the quality of aeromagnetic gradient tensor measurements, including systematic errors of the measurement system, magnetic interference from the carrying platform, and unexpected environmental impacts. But there are no methods for analyzing and identifying them at present. Therefore, we model an error source identification method based on a transforming deviation matrix, which is constructed according to the generalized Hilbert transform relations among the tensor components and reflects the error characteristics of the measurements. Our method provides a basis for guiding data processing and reducing waste of financial, material, and human resources through timely adjustments of experimental schemes. The correctness and engineering practicality of the method have been verified by simulation and field experiments.
{"title":"Error Characteristic Analysis and Error Source Identification of Aeromagnetic Field Gradient Tensor Measurements","authors":"Ke Liu;Hongsong Miao;Qiang Fu;Yuqi Pang;Yangyi Sui","doi":"10.1109/LMAG.2023.3290534","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3290534","url":null,"abstract":"Aeromagnetic gradient tensor measurement has become a powerful method in geological surveys, mineral resource exploration, and other applications due to its ability to resist temporal changes of the geomagnetic field and its ability to provide rich information and be highly efficient. Various factors may affect the quality of aeromagnetic gradient tensor measurements, including systematic errors of the measurement system, magnetic interference from the carrying platform, and unexpected environmental impacts. But there are no methods for analyzing and identifying them at present. Therefore, we model an error source identification method based on a transforming deviation matrix, which is constructed according to the generalized Hilbert transform relations among the tensor components and reflects the error characteristics of the measurements. Our method provides a basis for guiding data processing and reducing waste of financial, material, and human resources through timely adjustments of experimental schemes. The correctness and engineering practicality of the method have been verified by simulation and field experiments.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67762117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objective is to study the prediction of the electromagnetic (EM) field and the output performance of permanent magnet eddy current devices (PMECDs) based on a physics-informed sparse neural network (PISNN). In order to achieve this goal, a unified physical model is first defined according to different types of PMECDs, which is equivalent to solving a parameterized magnetic quasi-static problem. A soft constraint module and a hard constraint module, composed of physical equations, are constructed. The soft constraints are then integrated into the neural network's objective function, while the hard constraint module is utilized to predict device performance and physical field. Stochastic gradient descent is used to minimize the residual of the physical equations during PISNN training. Subsequently, the structural parameters and operating parameters of the PMECD are modified to verify the generalization ability of the model. Our results indicate that PISNN accurately and efficiently predicts the EM field distribution and the output torque. Furthermore, our prediction results for permanent magnet eddy current devices with different parameters demonstrate the potential of the method for transfer learning.
{"title":"Physics-Informed Sparse Neural Network for Permanent Magnet Eddy Current Device Modeling and Analysis","authors":"Dazhi Wang;Sihan Wang;Deshan Kong;Jiaxing Wang;Wenhui Li;Michael Pecht","doi":"10.1109/LMAG.2023.3288388","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3288388","url":null,"abstract":"The objective is to study the prediction of the electromagnetic (EM) field and the output performance of permanent magnet eddy current devices (PMECDs) based on a physics-informed sparse neural network (PISNN). In order to achieve this goal, a unified physical model is first defined according to different types of PMECDs, which is equivalent to solving a parameterized magnetic quasi-static problem. A soft constraint module and a hard constraint module, composed of physical equations, are constructed. The soft constraints are then integrated into the neural network's objective function, while the hard constraint module is utilized to predict device performance and physical field. Stochastic gradient descent is used to minimize the residual of the physical equations during PISNN training. Subsequently, the structural parameters and operating parameters of the PMECD are modified to verify the generalization ability of the model. Our results indicate that PISNN accurately and efficiently predicts the EM field distribution and the output torque. Furthermore, our prediction results for permanent magnet eddy current devices with different parameters demonstrate the potential of the method for transfer learning.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67762115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multiferroic nanomagnet neuron devices have the advantages of ultralow power consumption and high integration, which give them promising applications in neuromorphic computing. In this letter, a multiferroic nanomagnet neuron device driven by an inclined monopulse clock is modeled. The strain field direction of the device is at an angle to the nanomagnet's long axis, and the nanomagnet's magnetic moment can be driven to switch randomly 0°/180° by applying a pulse voltage of 0.1 ns pulse width only, thus realizing artificial neuron functions. The numerical model of the neuron device is established based on the Landau–Lifshitz–Gilbert equation. The numerical simulation results indicate that the neuron device can complete high-speed neuromorphic computation with tiny energy use (∼2.65 aJ). Additionally, a three-layer artificial neural network based on neuron devices is built. The simulation results demonstrate that the network can recognize handwritten digits in the Modified National Institute of Standards and Technology (MNIST) dataset at a rate of more than 98% and has a high tolerance for process error. The device has significant advantages over conventional spin neuron devices, including a simple structure, ultralow energy consumption, fast computation capabilities, and a wide fabrication process error tolerance range. The study results in this letter offer crucial theoretical recommendations for applying strain magneto-electronic devices in neuromorphic computing.
{"title":"Performance Simulation of Multiferroic Neuron Device Driven by an Inclined Monopulse Clock","authors":"Shuqing Dou;Xiaokuo Yang;Jiahui Yuan;Yongshun Xia;Xin Bai;Huanqing Cui;Bo Wei","doi":"10.1109/LMAG.2023.3287396","DOIUrl":"https://doi.org/10.1109/LMAG.2023.3287396","url":null,"abstract":"Multiferroic nanomagnet neuron devices have the advantages of ultralow power consumption and high integration, which give them promising applications in neuromorphic computing. In this letter, a multiferroic nanomagnet neuron device driven by an inclined monopulse clock is modeled. The strain field direction of the device is at an angle to the nanomagnet's long axis, and the nanomagnet's magnetic moment can be driven to switch randomly 0°/180° by applying a pulse voltage of 0.1 ns pulse width only, thus realizing artificial neuron functions. The numerical model of the neuron device is established based on the Landau–Lifshitz–Gilbert equation. The numerical simulation results indicate that the neuron device can complete high-speed neuromorphic computation with tiny energy use (∼2.65 aJ). Additionally, a three-layer artificial neural network based on neuron devices is built. The simulation results demonstrate that the network can recognize handwritten digits in the Modified National Institute of Standards and Technology (MNIST) dataset at a rate of more than 98% and has a high tolerance for process error. The device has significant advantages over conventional spin neuron devices, including a simple structure, ultralow energy consumption, fast computation capabilities, and a wide fabrication process error tolerance range. The study results in this letter offer crucial theoretical recommendations for applying strain magneto-electronic devices in neuromorphic computing.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"14 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67762071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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