IEEE Magnetics Letters最新文献

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Magnetic and Dielectric Properties of CoFeB Multilayer Thin Films With Oxide Capping Layer 带氧化物封盖层的 CoFeB 多层薄膜的磁性和介电特性
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-09-12 DOI: 10.1109/LMAG.2024.3459813
Yuting Liu;Sylvain Eimer;Jianyuan Zhao;Yiming Chen
{"title":"Magnetic and Dielectric Properties of CoFeB Multilayer Thin Films With Oxide Capping Layer","authors":"Yuting Liu;Sylvain Eimer;Jianyuan Zhao;Yiming Chen","doi":"10.1109/LMAG.2024.3459813","DOIUrl":"10.1109/LMAG.2024.3459813","url":null,"abstract":"Ferromagnetic multilayer thin films with oxide capping layer have potential applications in voltage-controlled magnetic devices. Here, we present the optimization of the magnetic and dielectric properties of CoFeB/MgO thin films with different capping layers (Ta, Al\u0000<sub>2</sub>\u0000O\u0000<sub>3</sub>\u0000, and HfO\u0000<sub>2</sub>\u0000). We find that the samples with oxide capping layers show a higher perpendicular magnetic anisotropy (PMA) than those with a Ta capping layer. Meanwhile, a high dielectric constant of 58 is obtained in samples capped with 30 nm of HfO\u0000<sub>2</sub>\u0000. This high dielectric constant is attributed to the formation of an oxygen vacancy-related capacitive double layer in the HfO\u0000<sub>2</sub>\u0000 film according to X-ray diffraction analyses and current–voltage measurements. Finally, we find that the optimal annealing temperature, which allows for both high PMA and dielectric constant, is between 250 °C and 290 °C. Our results could contribute to designing high-performance materials for controlling interfacial magnetic properties in novel spintronic devices.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193671","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}
引用次数: 0
Effect of Powder Particle Surface Treatment on DC Magnetic Properties of Compacted Iron Cores 粉末颗粒表面处理对压制铁芯直流磁性能的影响
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-08-26 DOI: 10.1109/LMAG.2024.3450334
Martin Tkáč;Peter Kollár;Robert Maciaszek;Samuel Dobák;Ján Füzer;Denisa Olekšáková;Radovan Bureš;Mária Fáberová
{"title":"Effect of Powder Particle Surface Treatment on DC Magnetic Properties of Compacted Iron Cores","authors":"Martin Tkáč;Peter Kollár;Robert Maciaszek;Samuel Dobák;Ján Füzer;Denisa Olekšáková;Radovan Bureš;Mária Fáberová","doi":"10.1109/LMAG.2024.3450334","DOIUrl":"10.1109/LMAG.2024.3450334","url":null,"abstract":"Soft magnetic iron finds practical use in many applications, such as electromagnets and relays. In order for these devices to work effectively, it is necessary to know their dc magnetic properties. Soft magnetic compacted powder cores possess lower permeability than powder particles from which they were prepared, due to the inner demagnetization factor caused by the existence of pores in the core structure. The aim of the work was to determine the effect of surface mechanical treatment of iron powder particles of two different size fractions, leading either to an increase in the demagnetization factor or to a positive effect on the dc magnetic properties of the resulting compacted cores. For samples prepared from smaller powder particles, we found, that despite the increase in inner demagnetization factor as a result of the smoothing procedure, the differential relative permeability increased, and total energy loss decreased.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10648613","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Exploring the Structural and Magnetic Properties of Cu-Rich CuxMn3−xO4 Spinels for Advanced Magnetic Refrigeration at Liquid Nitrogen Temperatures 探索用于液氮温度下先进磁制冷的富铜 CuxMn3-xO4 Spinels 的结构和磁特性
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-08-15 DOI: 10.1109/LMAG.2024.3443745
Abir Hadded;Igor Veremchuk;Shengqiang Zhou;Denys Makarov;Essebti Dhahri
{"title":"Exploring the Structural and Magnetic Properties of Cu-Rich CuxMn3−xO4 Spinels for Advanced Magnetic Refrigeration at Liquid Nitrogen Temperatures","authors":"Abir Hadded;Igor Veremchuk;Shengqiang Zhou;Denys Makarov;Essebti Dhahri","doi":"10.1109/LMAG.2024.3443745","DOIUrl":"https://doi.org/10.1109/LMAG.2024.3443745","url":null,"abstract":"Cu–Mn oxide spinels reveal notorious magnetocaloric performance at liquid nitrogen temperatures. We applied the soft chemistry sol–gel method to prepare Cu\u0000<italic><sub>x</sub></i>\u0000Mn\u0000<sub>3−</sub>\u0000<italic><sub>x</sub></i>\u0000O\u0000<sub>4</sub>\u0000 samples with nominal Cu content of \u0000<italic>x</i>\u0000 = 1, 1.5, 1.8, and 2. According to powder X-ray diffraction studies, we succeeded to fabricate multiphase samples with a high content of Cu in spinel phases. We provide insights into the structural and magnetic, as well as magnetocaloric, properties of the synthesized samples. We determine that in contrast to samples with \u0000<italic>x</i>\u0000 = 1.0 and 1.5, which are coupled ferromagnetically, the samples with \u0000<italic>x</i>\u0000 = 1.8 and 2.0 reveal ferrimagnetic coupling. The transition temperature is found to decrease only slightly from 78 K (\u0000<italic>x</i>\u0000 = 1) to 75 K (\u0000<italic>x</i>\u0000 = 2). The maximum values of the magnetic entropy change and relative cooling power are determined for each compound and found to be the largest for the sample with \u0000<italic>x</i>\u0000 = 1.0 due to its largest magnetization. Independent of the Cu content, here, the studied samples reveal a relative cooling power of larger than 139 J/kg, which highlights the relevance of these materials for magnetic refrigeration applications, particularly at liquid nitrogen temperatures.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174007","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}
引用次数: 0
A Variable Stiffness Methodology to Extend Travel Range of Micro Electromagnetic Actuators 扩展微型电磁致动器行程范围的可变刚度方法
IF 1.2 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-08-13 DOI: 10.1109/lmag.2024.3442710
Xian Shi, Changda Yang, Kerong Cai, Xu Wang, Yinghu Liu, Zekai Zhang, Feng Yu, Biao Ji, Guangwei Meng
{"title":"A Variable Stiffness Methodology to Extend Travel Range of Micro Electromagnetic Actuators","authors":"Xian Shi, Changda Yang, Kerong Cai, Xu Wang, Yinghu Liu, Zekai Zhang, Feng Yu, Biao Ji, Guangwei Meng","doi":"10.1109/lmag.2024.3442710","DOIUrl":"https://doi.org/10.1109/lmag.2024.3442710","url":null,"abstract":"","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193669","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}
引用次数: 0
Impact of Off-Axis External Magnetic Field Perturbation on the Write Error Slopes of Perpendicular STT-RAM Cell: Micromagnetic Study 离轴外部磁场扰动对垂直 STT-RAM 单元写入误差斜率的影响:微磁研究
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-07-18 DOI: 10.1109/LMAG.2024.3430189
Susheel K. Arya;Sonalie Ahirwar;Tanmoy Pramanik
{"title":"Impact of Off-Axis External Magnetic Field Perturbation on the Write Error Slopes of Perpendicular STT-RAM Cell: Micromagnetic Study","authors":"Susheel K. Arya;Sonalie Ahirwar;Tanmoy Pramanik","doi":"10.1109/LMAG.2024.3430189","DOIUrl":"10.1109/LMAG.2024.3430189","url":null,"abstract":"External magnetic field perturbation remains a key reliability issue for spin-transfer-torque magnetic random-access memory. Although several prototypes have been demonstrated already, the effects of external fields with varying directions are not well reported. Our macrospin-based study revealed a significant increase in write failures in the presence of small off-axis external magnetic fields. However, incoherent switching pathways, which are also known to impact the switching process, cannot be captured by a macrospin model. Here, we report the micromagnetic model study of the switching process of perpendicular nanomagnets in the presence of magnetic fields of varying magnitudes and directions. The results are consistent with the macrospin model prediction for smaller magnet sizes. For larger magnet sizes, the impact of the off-axis external magnetic field becomes much worse when incoherent magnetization modes dominate the switching process.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.1,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141738173","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}
引用次数: 0
One Trillion True Random Bits Generated With a Field-Programmable Gate Array Actuated Magnetic Tunnel Junction 利用场可编程门阵列驱动磁隧道结生成一万亿真实随机比特
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-06-18 DOI: 10.1109/LMAG.2024.3416091
Andre Dubovskiy;Troy Criss;Ahmed Sidi El Valli;Laura Rehm;Andrew D. Kent;Andrew Haas
{"title":"One Trillion True Random Bits Generated With a Field-Programmable Gate Array Actuated Magnetic Tunnel Junction","authors":"Andre Dubovskiy;Troy Criss;Ahmed Sidi El Valli;Laura Rehm;Andrew D. Kent;Andrew Haas","doi":"10.1109/LMAG.2024.3416091","DOIUrl":"10.1109/LMAG.2024.3416091","url":null,"abstract":"Large quantities of random numbers are crucial in a wide range of applications. We have recently demonstrated that perpendicular nanopillar magnetic tunnel junctions (pMTJs) can produce true random bits when actuated with short pulses. However, our implementation used high-end and expensive electronics, such as a high-bandwidth arbitrary waveform generator and analog-to-digital converter, and was limited to relatively low data rates. Here, we significantly increase the speed of true random-number generation of our stochastic actuated pMTJs (SMART-pMTJs) using field-programmable gate arrays (FPGAs), demonstrating the generation of over \u0000<inline-formula><tex-math>${text{10}}^{text{12}}$</tex-math></inline-formula>\u0000 bits at rates exceeding 10 Mb/s. The resulting bitstreams pass the NIST Statistical Test Suite for randomness with only one \u0000<sc>xor</small>\u0000 operation. In addition to a hundred-fold reduction in the setup cost and a thousand-fold increase in bitrate, the advancement includes simplifying and optimizing random bit generation with a custom-designed analog daughterboard to interface an FPGA and SMART-pMTJ. The resulting setup further enables FPGA at-speed processing of MTJ data for stochastic modeling and cryptography.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-4"},"PeriodicalIF":1.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10561576","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Multiplexer-Based High-Capacity Spintronic Synapse 基于多路复用器的高容量自旋电子突触
IF 1.1 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-06-18 DOI: 10.1109/LMAG.2024.3416092
Mahan Rezaei;Ermia Elahi;Arefe Amirany;Mohammad Hossein Moaiyeri
{"title":"A Multiplexer-Based High-Capacity Spintronic Synapse","authors":"Mahan Rezaei;Ermia Elahi;Arefe Amirany;Mohammad Hossein Moaiyeri","doi":"10.1109/LMAG.2024.3416092","DOIUrl":"10.1109/LMAG.2024.3416092","url":null,"abstract":"In recent years, there have been significant advancements in the manufacturing of emerging technologies, especially in the areas of in-memory computing and neural networks, which are currently some of the most actively researched topics. With the increasing need to process complex tasks, the development of intelligent processors has become more crucial than ever. This letter advances a high-capacity spintronic synapse using magnetic tunnel junctions (MTJs) and carbon nanotube field-effect transistors (CNTFETs) to implement associative memory. The choice of MTJ devices is due to their remarkable features, including reliable reconfiguration and nonvolatility. Moreover, CNTFETs have overcome traditional complementary metal–oxide semiconductor limitations, such as the short-channel effect and suboptimal hole mobility. The design seeks to improve accuracy and memory capacity by increasing the number of weights. Simulation results indicate that the design offers a 19%–73% higher number of weights and a lower error rate than the state-of-the-art counterparts.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934114","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}
引用次数: 0
Magnetic and Microstructural Characterization of Carburized 25Cr35NiNb Alloy 渗碳 HP 合金的磁性和微观结构表征
IF 1.2 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-03-18 DOI: 10.1109/LMAG.2024.3376152
Shukai Chen;Minghao Zhang;Ke Huang;Genghao Jiao;Yihua Kang;Bo Feng
{"title":"Magnetic and Microstructural Characterization of Carburized 25Cr35NiNb Alloy","authors":"Shukai Chen;Minghao Zhang;Ke Huang;Genghao Jiao;Yihua Kang;Bo Feng","doi":"10.1109/LMAG.2024.3376152","DOIUrl":"10.1109/LMAG.2024.3376152","url":null,"abstract":"During the service of an HP tube, carbon diffuses into the tube wall, forming a carburization layer and reducing the mechanical strength. To quantitatively measure the carburization layer thickness, its magnetic properties should be accurately characterized. Magnetic properties, including saturation magnetization and magnetic permeability, of chromium-depleted HP alloy have been characterized by a vibration sample magnetometer and the eddy current method. The microstructural observations were made using optical microscopy and scanning electron microscopy. The change of the magnetic properties with chromium content has been quantitatively obtained. The results show that the saturated mass magnetization and magnetic permeability have abrupt increases when chromium content is less than 14.6% and 11.8%, respectively. The obtained properties were further used to quantitatively evaluate the carburization layer thickness in a slice of ex-serviced tube. The estimation error was less than 0.33 mm, indicating the characterized magnetic properties are effective for the carburization layer measurement.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169211","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}
引用次数: 0
Complementary-Magnetization-Switching Perpendicular Spin-Orbit Torque Random-Access Memory Cell for High Read Performance 实现高读取性能的互补磁化开关垂直自旋轨道转矩随机存取存储器单元
IF 1.2 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-03-03 DOI: 10.1109/LMAG.2024.3396750
Hao Zhang;Di Wang;Long Liu;Yu Liu;Huai Lin;Yifan Zhang;Changqing Xie
{"title":"Complementary-Magnetization-Switching Perpendicular Spin-Orbit Torque Random-Access Memory Cell for High Read Performance","authors":"Hao Zhang;Di Wang;Long Liu;Yu Liu;Huai Lin;Yifan Zhang;Changqing Xie","doi":"10.1109/LMAG.2024.3396750","DOIUrl":"10.1109/LMAG.2024.3396750","url":null,"abstract":"The read reliability of spin-transfer torque magnetic random-access memory (STT-MRAM) is greatly hindered by a low sensing margin as a result of a small tunneling magnetoresistance ratio. Although the new generation of perpendicular anisotropy spin-orbit torque (SOT)-MRAM offers faster access speed and a longer lifetime than STT-MRAM, its read performance has not improved or even deteriorated because of the additional resistance of the SOT channel in the read path. In this letter, we propose two novel cell structures of SOT-MRAM that consist of one/two transistors, two diodes, and two magnetic tunnel junctions (1T2D2MTJ/2T2D2MTJ) on a shared U-shaped antiferromagnet layer, enabling a self-referencing scheme. Thanks to the bent current channel, the opposite direction of the SOT current below the free layers can one-step switch different data states in compatibility with the existing fabrication process of SOT-MRAM. Combined with the 28 nm tech node and Verilog-A MTJ compact model, the simulation results show that our MRAM cell significantly improves the sensing margin and bit error rate over the conventional two transistors and one MTJ (2T1M) cell, which is expected to become a high read performance solution.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2024-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140842453","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}
引用次数: 0
Design and Testing of a Compact, Portable Single-Pulse Transcranial Magnetic Stimulation Device 设计和测试小型便携式 sTMS 设备
IF 1.2 4区 物理与天体物理
IEEE Magnetics Letters Pub Date : 2024-02-28 DOI: 10.1109/LMAG.2024.3371370
Wesley Lawson
{"title":"Design and Testing of a Compact, Portable Single-Pulse Transcranial Magnetic Stimulation Device","authors":"Wesley Lawson","doi":"10.1109/LMAG.2024.3371370","DOIUrl":"10.1109/LMAG.2024.3371370","url":null,"abstract":"We describe the design and preliminary testing of a portable single-pulse transcranial magnetic stimulation (sTMS) device for the possible treatment of migraine headaches. The design requirements are presented, and tradeoffs/options for some of the key components are analyzed. Details of the design are given, and performance results of the initial prototype are compared with the theoretical predictions, demonstrating the viability of the design.","PeriodicalId":13040,"journal":{"name":"IEEE Magnetics Letters","volume":"15 ","pages":"1-5"},"PeriodicalIF":1.2,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140011487","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}
引用次数: 0
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