{"title":"Correlation Between Temperature and Domain State Configuration in Fe2CoGe Thin Film","authors":"Rajesh Kumar Roul;Bongurala Prakash;S. Narayana Jammalamadaka","doi":"10.1109/TMAG.2025.3555522","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3555522","url":null,"abstract":"We present findings regarding room temperature first-order reversal curve (FORC) analysis of Fe2CoGe Heusler alloy thin films subjected to varying annealing temperatures in the range of <inline-formula> <tex-math>$100~^{circ }$ </tex-math></inline-formula>C–<inline-formula> <tex-math>$400~^{circ }$ </tex-math></inline-formula>C. Our study suggests that the magnetostatic interactions (MIs) among magnetic grains decrease with the annealing temperature of Fe2CoGe thin films. This observation is further supported by the analysis of the switching field distribution (SFD). The transformation from multidomain (MD) to vortex domain (VD) structures is evident at different annealing temperatures. The alterations in domain state configuration associated with varied annealing temperatures could potentially enhance the applicability of Fe2CoGe Heusler alloy films for future spintronic applications.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 6","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inclining-Interface Connected Integrated-Parallel-Magnetization Trapezoidal-Magnetic-Pole Combination BPMSM and Its Magnetic Field Analytical Calculation","authors":"Wenshao Bu;Jinghui Zhang;Zongang Fan","doi":"10.1109/TMAG.2025.3574067","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3574067","url":null,"abstract":"For the bearingless permanent magnet synchronous motor (BPMSM), to improve the sinusoidal degree of air-gap magnetic field, and solve the problem of difficulty in solving the air-gap magnetic field, a novel structure of Inclining-interface Connected Trapezoidal-Magnetic-Pole Combination with integrated Parallel Magnetization (ICTMPC-PM) is proposed, and for the BPMSM with ICTMPC-PMs, the analytical calculation model of the no-load air-gap magnetic field is studied under the consideration of the rotor eccentricity. First, the analytical equation of air-gap flux density for the slotless BPMSM with ICTMPC-PMs is obtained by solving Laplace’s and Poisson’s equations in each subdomain. Then, combining the relative permeability function, the analytical equations of radial air-gap flux density are further solved for the slotted BPMSM with ICTMPC-PMs. Subsequently, combining with the equivalent air-gap function and under the consideration of the radial eccentricity of the bearingless rotor, the analytical equations of radial air-gap flux density are achieved. Finally, through the finite element method (FEM), the characteristic comparison of the no-load air-gap magnetic field and the validation of the analytical calculation model for a BPMSM with ICTMPC-PMs are conducted. From the research results, the BPMSM structure with ICTMPC-PMs can significantly reduce the low-order harmonics of the air-gap magnetic field, such as the third, fifth, and seventh harmonics, thereby significantly improve the sinusoidal degree of the air-gap magnetic flux density waveform; The established analytical calculation model of air-gap magnetic field for the BPMSM with ICTMPC-PMs is effective and has a high accuracy.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 7","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"IEEE Magnetics Society Information","authors":"","doi":"10.1109/TMAG.2025.3550293","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3550293","url":null,"abstract":"","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 4","pages":"C2-C2"},"PeriodicalIF":2.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10942486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a Dual-Spring Linear Resonant Actuator for Improved Haptic Performance","authors":"Kyeongtak Park;Younghun Jeong;Danping Xu;Sangmoon Hwang","doi":"10.1109/TMAG.2025.3554743","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3554743","url":null,"abstract":"This study proposes a novel dual-spring linear resonant actuator (LRA) designed to enhance haptic feedback in tactile devices, particularly haptic controllers. The design aims to improve acceleration performance compared with the one-spring existing prototype. The new type allows for larger magnets and moving mass within the same size constraints. Both the prototype and new type were analyzed using an electromagnetic-mechanical coupled model to evaluate their acceleration and displacement. The new type shows a 0.32 mm decrease in maximum displacement and a 0.58 G increase in maximum acceleration on dummy jig at the same input voltage, compared with the prototype. To validate the analysis results, a sample of the new type is fabricated and tested using a vibration analyzer and Klippel equipment. The experimental results confirm the improved haptic performance of the dual-spring structure, thus demonstrating its potential to provide superior haptic feedback with stronger vibration.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 9","pages":"1-5"},"PeriodicalIF":1.9,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengjie Xiang;Liang Yan;Xiaoshuai Liu;Xinyi Li;Xinghua He;Wei Hua;Cungang Hu
{"title":"A Field-Superposition Model for Fast Electromagnetic Performance Prediction of PM Machine With Irregular Magnets and Irons","authors":"Pengjie Xiang;Liang Yan;Xiaoshuai Liu;Xinyi Li;Xinghua He;Wei Hua;Cungang Hu","doi":"10.1109/TMAG.2025.3573334","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3573334","url":null,"abstract":"Accurate and fast prediction of air-gap magnetic field is critical for the design and optimization of spoke-type permanent-magnet (PM) machines especially those with high slot/pole number and irregular-shaped magnets. Conventional field-superposition analytical model is a fast computation method for electromagnetic performance prediction of PM machines; however, it cannot be directly used in the spoke-type PM machines with irregular magnets and interpolar irons. In this article, an improved field-superposition method based on segmented virtual domains (SVDs) is proposed to achieve high-precision and fast magnetic field prediction of the spoke-type PM machine accounting for irregular magnets and interpolar irons. The number of domains requiring modeling can be reduced effectively to save computation time, and the inter-layer magnetic resistance of the interpolar iron can be taken account for high precision by the improved field-superposition method. First, the schematic of one spoke-type PM machine with quasi-trapezoidal magnet and quasi-triangular iron is presented, and the major features of the proposed analytical modeling method are discussed and compared with conventional superposition method. Second, by taking advantage of the segmented virtual-domain method along with half-range Fourier series expansion, the open-circuit air-gap field with and without stator slots, the back electromotive force, and the torque output of the electric machine are formulated mathematically. Finally, the finite-element method is conducted on the electromagnetic performance calculation to validate the improved field-superposition method. The results show that the analytical model agrees with the numerical results well, and the computation time can be reduced from 92 to 0.631 s.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 7","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chao Cui;Xiaochun Fang;Jinkai Wang;Yaxuan Li;Zhongping Yang;Fei Lin
{"title":"A Linear Eddy Current Braking System With Normal Force Suppression Function for Electrodynamic Suspension Train","authors":"Chao Cui;Xiaochun Fang;Jinkai Wang;Yaxuan Li;Zhongping Yang;Fei Lin","doi":"10.1109/TMAG.2025.3573300","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3573300","url":null,"abstract":"The linear eddy current braking (LECB) system is suitable for use as an emergency braking system to ensure the safe and stable operation of high-speed maglev trains. This article analyzes the adverse effects of the normal force generated by eddy currents on the stable levitation of the electrodynamic suspension (EDS) train. From the perspective of electromagnetic mechanisms, it elucidates the intrinsic relationship between the magnetic field distribution and the resulting eddy current electromagnetic forces. Based on this theoretical framework, a novel parallel hybrid excitation (PHE) eddy current braking electromagnetic structure is proposed for the EDS train. The aim is to suppress the normal force without reducing the braking force. Using the subdomain method and the principle of equivalent magnetic vector potential, a spatiotemporal distribution model of magnetic flux density, along with analytical models for the eddy current braking force and normal force, is developed. Key parameters influencing the system’s electromagnetic performance are identified. The analytical model’s accuracy is validated through 3-D finite element simulations, confirming the effectiveness of the proposed structure and providing a theoretical basis for its application in EDS trains.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 7","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144536453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yash R. Saxena;Connor J. Lewis;Muhammad Sabbir Alam;Jayasimha Atulasimha;Urvakhsh M. Mehta;Ravi L. Hadimani
{"title":"A Hybrid Machine Learning Algorithm for Predicting Resting Motor Thresholds in Patients With Schizophrenia and Healthy Individuals Undergoing Transcranial Magnetic Stimulation","authors":"Yash R. Saxena;Connor J. Lewis;Muhammad Sabbir Alam;Jayasimha Atulasimha;Urvakhsh M. Mehta;Ravi L. Hadimani","doi":"10.1109/TMAG.2025.3554122","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3554122","url":null,"abstract":"Due to the complex and varied neuroanatomy and functional states of brains, it is difficult to predict the resting motor threshold (RMT) needed as a dose parameter for treatment with transcranial magnetic stimulation (TMS). Our prior publications have shown that anatomical parameters, such as coil-to-cortex distance (CCD), gray matter volume (GMV), depolarized GMV (DGMV), and maximum electric field (E-field) value, neuroanatomy, and connectivity derived from functional magnetic resonance imaging (fMRI) are all associated with RMT. For 54 subjects with schizophrenia and 43 healthy subjects, fMRI blood oxygen-level detection (BOLD) in 25 brain regions was turned into time series and fed into a long short-term memory (LSTM) model. The outputs of the LSTM are concatenated with the schizophrenia status, CCD, GMV, percentage of gray matter voxels depolarized over 50 V/m (DGMV50) and 100 V/M (DGMV100), and maximum E-field value and then fed into an artificial neural network (ANN) that predicted the RMT. The training and testing mean absolute errors (MAEs) are 0.1176 and 0.0845, respectively, corresponding to the errors of 3.6456% and 2.6195% of the maximum stimulator output (%MSO) in the predicted RMT values. Our novel hybrid LSTM-ANN neural network can be used as a pretreatment procedure to reduce the number of trials needed to measure RMT for patients and increase patient comfort and confidence in the procedure administered.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 9","pages":"1-6"},"PeriodicalIF":1.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}