Magnetochemistry最新文献_第7页

The Magnetostriction of Amorphous Magnetic Microwires: The Role of the Local Atomic Environment and Internal Stresses Relaxation 非晶磁微线的磁致伸缩:局部原子环境和内应力松弛的作用

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Magnetochemistry Pub Date : 2023-10-20 DOI: 10.3390/magnetochemistry9100222

Valentina Zhukova, Alfonso García-Gómez, Alvaro Gonzalez, Margarita Churyukanova, Sergey Kaloshkin, Paula Corte-Leon, Mihail Ipatov, Jesus Olivera, Arcady Zhukov

{"title":"The Magnetostriction of Amorphous Magnetic Microwires: The Role of the Local Atomic Environment and Internal Stresses Relaxation","authors":"Valentina Zhukova, Alfonso García-Gómez, Alvaro Gonzalez, Margarita Churyukanova, Sergey Kaloshkin, Paula Corte-Leon, Mihail Ipatov, Jesus Olivera, Arcady Zhukov","doi":"10.3390/magnetochemistry9100222","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100222","url":null,"abstract":"We studied the magnetostriction coefficients, λs, Curie temperature, Tc, and their dependence on annealing conditions in Fe47Ni27Si11B13C2 and Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 amorphous glass-coated microwires with rather different character of hysteresis loops. A positive λs ≈ 20 × 10−6 is observed in as-prepared Fe47Ni27Si11B13C2, while low and negative λs ≈ −0.3 × 10−6 is obtained for Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 microwire. Annealing affects the magnetostriction coefficients and Curie temperatures, Tc, of both Fe47Ni27Si11B13C2 and Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 glass-coated microwires in a similar way. Observed dependencies of hysteresis loops, λs and Tc on annealing conditions are discussed in terms of superposition of internal stresses relaxation and structural relaxation of studied microwires. We observed linear λs dependence on applied stress, σ, in both studied microwires. A decrease in the magnetostriction coefficient upon applied stress is observed for Co-rich microwires with low and negative magnetostriction coefficient. On the contrary, for Fe-Ni-rich microwires with a positive magnetostriction coefficient, an increase in the magnetostriction coefficient with applied stress is observed. The observed results are discussed considering the internal stresses relaxation and short range atomic rearrangements induced by annealing on hysteresis loops, magnetostriction coefficients and Curie temperatures of studied microwires.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135617427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of Radiation Damping Rates Using 133Cs, 7Li and 31P Solution NMR Spectroscopy and a Theoretical NMR RASER Model 用133Cs, 7Li和31P溶液核磁共振光谱和理论核磁共振激光模型估计辐射阻尼率

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Magnetochemistry Pub Date : 2023-10-18 DOI: 10.3390/magnetochemistry9100221

Eisuke Chikayama, Stephan J. Ginthör, Matthias Bechmann, Norbert Müller

{"title":"Estimation of Radiation Damping Rates Using 133Cs, 7Li and 31P Solution NMR Spectroscopy and a Theoretical NMR RASER Model","authors":"Eisuke Chikayama, Stephan J. Ginthör, Matthias Bechmann, Norbert Müller","doi":"10.3390/magnetochemistry9100221","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100221","url":null,"abstract":"Radio amplification using stimulated emission of radiation (RASER) effects in the NMR can increase NMR signals over time due to a feedback loop between the sample magnetization and the probe coil coupled with radiation damping (RD). Previously, RD rates had been directly observed only for the 1H, 3He, 17O and 129Xe nuclei. We report that experimental direct measurements of an NMR RASER to determine RD time constants for the three heteronuclei (133Cs (I = 7/2), 7Li (I = 3/2) and 31P (I = 1/2)) in a highly concentrated solution from the NMR RASER emissions using a conventional NMR probe. Under conditions where the RD rate exceeds the transverse relaxation rate (i.e., the NMR RASER condition is fulfilled), we recorded both the transverse NMR RASER response to imperfect inversion and the recovery of longitudinal magnetization. The data were directly evaluated based on the well-known Bloom model as estimated RD rate constants of 8.0, 1.8 and 25 Hz for 133Cs, 7Li and 31P, respectively. The proposed method can be applied to observe RD rate constants for the other nuclei as well.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135887947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature Dependence of Magnetization Dynamics in Co/IrMn and Co/FeMn Exchange Biased Structures Co/IrMn和Co/FeMn交换偏置结构磁化动力学的温度依赖性

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Magnetochemistry Pub Date : 2023-10-08 DOI: 10.3390/magnetochemistry9100218

Irina O. Dzhun, Andrey V. Gerasimenko, Alexander A. Ezhov, Stanislav I. Bezzubov, Valeria V. Rodionova, Christina A. Gritsenko, Nikolai G. Chechenin

{"title":"Temperature Dependence of Magnetization Dynamics in Co/IrMn and Co/FeMn Exchange Biased Structures","authors":"Irina O. Dzhun, Andrey V. Gerasimenko, Alexander A. Ezhov, Stanislav I. Bezzubov, Valeria V. Rodionova, Christina A. Gritsenko, Nikolai G. Chechenin","doi":"10.3390/magnetochemistry9100218","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100218","url":null,"abstract":"Thin film ferromagnet/antiferromagnet (F/AF) exchange biased structures that are widely used in GMR spin valves are considered nowadays as promising systems for antiferromagnetic spintronic and spin-orbitronic devices. Here, the temperature dependences of magnetization dynamics in Co/IrMn and Co/FeMn F/AF structures are investigated using ferromagnetic resonance (FMR) in comparison to a free Co layer. A strong additional decrease in the resonance field was observed in Co/IrMn with a temperature decrease attributed to the rotatable anisotropy increase, which almost vanished at room temperature. In contrast to Co/IrMn, the contribution of the rotatable anisotropy in Co/FeMn is much weaker, even though it exists at RT, it is negative, and slightly varies with the temperature and resonance field shift in Co/FeMn. This is mainly due to unidirectional exchange anisotropy. FMR linewidth for the free Co layer increases with decreasing temperature and is accompanied with a slow relaxation process, while the additional contribution to FMR line broadening in Co/IrMn and Co/FeMn structures is correlated with variation in the exchange anisotropy. The observed results are discussed based on structural and surface morphology and magnetization reversal characterization using X-ray diffraction, atomic force microscopy, and vibrating sample magnetometry data.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135197923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase Separation in the Double Perovskite Sr2FeNbO6-δ 双钙钛矿Sr2FeNbO6-δ的相分离

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Magnetochemistry Pub Date : 2023-10-08 DOI: 10.3390/magnetochemistry9100219

Daniil Popov, Ruslan Batulin, Mikhail Cherosov, Farit Vagizov, Almaz Zinnatullin, Tatiana Chupakhina, Yuliya Deeva, Tanmoy Maiti, Rushana Eremina

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Superparamagnetism of Artificial Glasses Based on Rocks: Experimental Data and Theoretical Modeling 基于岩石的人造玻璃的超顺磁性:实验数据和理论建模

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Magnetochemistry Pub Date : 2023-10-08 DOI: 10.3390/magnetochemistry9100220

Petr Kharitonskii, Elena Sergienko, Andrey Ralin, Evgenii Setrov, Timur Sheidaev, Kamil Gareev, Alexander Ustinov, Nikita Zolotov, Svetlana Yanson, Danil Dubeshko

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In One Fell Sweep: Modeling Exchange, Hyperfine and Dipolar Interactions from EPR Spectra of Copper(II) Spin Triangles 从铜(II)自旋三角形的EPR光谱模拟交换、超精细和偶极相互作用

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Magnetochemistry Pub Date : 2023-10-06 DOI: 10.3390/magnetochemistry9100217

Athanassios K. Boudalis

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Design and Numerical Study of Magnetic Energy Storage in Toroidal Superconducting Magnets Made of YBCO and BSCCO YBCO和BSCCO环形超导磁体磁能存储的设计与数值研究

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Magnetochemistry Pub Date : 2023-10-01 DOI: 10.3390/magnetochemistry9100216

Radu Jubleanu, Dumitru Cazacu

{"title":"Design and Numerical Study of Magnetic Energy Storage in Toroidal Superconducting Magnets Made of YBCO and BSCCO","authors":"Radu Jubleanu, Dumitru Cazacu","doi":"10.3390/magnetochemistry9100216","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100216","url":null,"abstract":"The superconducting magnet energy storage (SMES) has become an increasingly popular device with the development of renewable energy sources. The power fluctuations they produce in energy systems must be compensated with the help of storage devices. A toroidal SMES magnet with large capacity is a tendency for storage energy because it has great energy density and low stray field. A key component in the creation of these superconducting magnets is the material from which they are made. The present work describes a comparative numerical analysis with finite element method, of energy storage in a toroidal modular superconducting coil using two types of superconducting material with different properties bismuth strontium calcium copper oxide (BSCCO) and yttrium barium copper oxide (YBCO). Regarding the design of the modular torus, it was obtained that for a 1.25 times increase of the critical current for the BSCCO superconducting material compared with YBCO, the dimensions of the BSCCO torus were reduced by 7% considering the same stored energy. Also, following a numerical parametric analysis, it resulted that, in order to maximize the amount of energy stored, the thickness of the torus modules must be as small as possible, without exceeding the critical current. Another numerical analysis showed that the energy stored is maximum when the major radius of the torus is minimum, i.e., for a torus as compact as possible.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135407654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Investigation of Ferrofluid Sessile Droplet Tensile Deformation in a Uniform Magnetic Field 均匀磁场下铁磁流体固体液滴拉伸变形研究

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Magnetochemistry Pub Date : 2023-09-30 DOI: 10.3390/magnetochemistry9100215

Gui-Ping Zhu, Shi-Hua Wu, Shu-Ze Zheng, Lai Li, Nam-Trung Nguyen

{"title":"Investigation of Ferrofluid Sessile Droplet Tensile Deformation in a Uniform Magnetic Field","authors":"Gui-Ping Zhu, Shi-Hua Wu, Shu-Ze Zheng, Lai Li, Nam-Trung Nguyen","doi":"10.3390/magnetochemistry9100215","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100215","url":null,"abstract":"A significant growth of research on digital microfluidics has been achieved over the past several decades, and the field is still attracting increasing attention for fulfilling relevant mechanisms and potential applications. Numerous studies have been devoted to actively manipulating droplets in a variety of fundamental and applicational scenarios. In this work, the deformation of ferromagnetic fluid droplets is studied under an external uniform magnetic field. The droplets are precisely dispersed on the bottom surface of a container assembled with polymer methacrylate (PMMA) plates. Mineral oil is applied instead of air as the surrounding medium for easy stretching and preventing water solvent evaporation in ferrofluid. The design and processing of the container are firstly carried out to observe the shape and characterize the wettability of the droplets in the immiscible mineral oil medium. Furthermore, the droplets’ deformation and the working mechanism are given under the action of the horizontal uniform magnetic field. At different magnetic field intensities, the droplet is stretched in the horizontal direction parallel to the applied field. Due to volume conservation, the dimension in the height reduces correspondingly. With the coupling effect of magnetic force, viscous force and interfacial tension, the contact angle first increases with the magnetic field and then basically remains unchanged upon magnetization saturation. Consistent with the experimental results, the numerical method clearly reveals the field coupling mechanism and the nonlinear deformation of the sessile droplet.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136343653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Equivalent Noise Analysis and Modeling for a Magnetic Tunnel Junction Magnetometer with In Situ Magnetic Feedback 具有原位磁反馈的磁隧道结磁强计等效噪声分析与建模

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Magnetochemistry Pub Date : 2023-09-29 DOI: 10.3390/magnetochemistry9100214

Aiyu Dou, Ru Bai, Yucheng Sun, Jiakun Tu, Chuanjia Kou, Xin Xie, Zhenghong Qian

{"title":"Equivalent Noise Analysis and Modeling for a Magnetic Tunnel Junction Magnetometer with In Situ Magnetic Feedback","authors":"Aiyu Dou, Ru Bai, Yucheng Sun, Jiakun Tu, Chuanjia Kou, Xin Xie, Zhenghong Qian","doi":"10.3390/magnetochemistry9100214","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100214","url":null,"abstract":"Magnetic tunnel junction (MTJ) sensors have been one of the excellent candidates for magnetic field detection due to their high sensitivity and compact size. In this paper, we design a magnetometer with in situ magnetic feedback consisting of an MTJ sensor. To analyze and evaluate the detectivity of the MTJ magnetometer, a noise model of the MTJ sensor in the magnetometer without magnetic feedback is first developed. Then, the noise model of the MTJ magnetometer with in situ magnetic feedback is also established, including the noises of the MTJ sensor and the signal conditioning circuit, as well as the feedback circuit. The equivalent noise model of the MTJ magnetometer with in situ magnetic feedback is evaluated through nonlinear fitting for the noise voltage spectrum. Although the noise generated by the MTJ sensor is much greater than that of the signal conditioning circuit, the noise introduced by the feedback coils into the MTJ sensor is slightly more than twice that generated by the MTJ sensor itself. The measurement results show that the detectivity of the MTJ magnetometer with in situ magnetic feedback reaches 526 pT/Hz1/2 at 10 Hz. The equivalent noise analysis method presented in this paper is suitable for the detectivity analysis of magnetometers with magnetic feedback.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135246036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polymer-Assisted Synthesis, Structure and Magnetic Properties of Bimetallic FeCo- and FeNi/N-Doped Carbon Nanocomposites 双金属FeCo和FeNi/ n掺杂碳纳米复合材料的聚合物辅助合成、结构和磁性能

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Magnetochemistry Pub Date : 2023-09-27 DOI: 10.3390/magnetochemistry9100213

Gulsara D. Kugabaeva, Kamila A. Kydralieva, Lyubov S. Bondarenko, Rose K. Baimuratova, Dmitry Yu. Karpenkov, Ekaterina A. Golovkova, Pavel N. Degtyarenko, Nina D. Golubeva, Igor E. Uflyand, Gulzhian I. Dzhardimalieva

{"title":"Polymer-Assisted Synthesis, Structure and Magnetic Properties of Bimetallic FeCo- and FeNi/N-Doped Carbon Nanocomposites","authors":"Gulsara D. Kugabaeva, Kamila A. Kydralieva, Lyubov S. Bondarenko, Rose K. Baimuratova, Dmitry Yu. Karpenkov, Ekaterina A. Golovkova, Pavel N. Degtyarenko, Nina D. Golubeva, Igor E. Uflyand, Gulzhian I. Dzhardimalieva","doi":"10.3390/magnetochemistry9100213","DOIUrl":"https://doi.org/10.3390/magnetochemistry9100213","url":null,"abstract":"Bimetallic FeCo and FeNi nanoparticles attract much attention due to their promising magnetic properties and a wide range of practical applications as recording and storage media, catalytic systems in fuel cells, supercapacitors, lithium batteries, etc. In this paper, we propose an original approach to the preparation of FeCo- and FeNi/N-doped carbon nanocomposites by means of a coupled process of frontal polymerization and thermolysis of molecular co-crystallized acrylamide complexes. The phase composition, structure, and microstructure of the resulting nanocomposites are studied using XRD, IR spectroscopy, elemental and thermal analysis, and electron microscopy data. The main magnetic characteristics of the synthesized nanocomposites, including the field dependences and the ZFC-FC curves peculiarities, are studied. It is shown that the obtained FeCo/N-C nanocomposites exhibit exchange bias behavior at low temperatures. In turn, FeNi/N-C nanocomposites are ferromagnetically ordered.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135579824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0