Article
Chemistry, Multidisciplinary
Devika Sudsom, Andrea Ehrmann
Summary: Combining clusters of magnetic materials with a matrix of other magnetic materials can lead to the discovery of new magnetic properties or magnetization reversal processes, which is important for basic research. Micromagnetic simulations show that magnetization reversal is influenced by neighboring nanodots and the magnetic matrix, providing important insights for data storage and processing applications.
Article
Materials Science, Multidisciplinary
A. Ehrmann, T. Blachowicz
Summary: Asymmetric hysteresis loops can be observed in exchange-bias systems and in purely ferromagnetic samples due to minor loops or thermal effects. Micromagnetic simulations of a nanoparticle structure reveal distinctly asymmetric and horizontally shifted hysteresis loops.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Yuqing Li, Yuan Teng, Xiaochang Xu, Yu Zhang, Ming Yue
Summary: The openness of recoil loops is not affected by inter-phase exchange coupling effect. The irreversibility of the reversal of hard-phase grains and the presence of adjacent soft phase play significant roles in determining the openness degree.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Mohamed Salaheldeen, Ayman Nafady, Ahmed M. Abu-Dief, Rosario Diaz Crespo, Maria Paz Fernandez-Garcia, Juan Pedro Andres, Ricardo Lopez Anton, Jesus A. Blanco, Pablo Alvarez-Alonso
Summary: The interest in magnetic nanostructures with perpendicular magnetic anisotropy and exchange bias has grown due to their potential applications in spintronic devices. In this study, a nanofabrication process was used to induce a significant out-of-plane component of the magnetic easy axis and exchange bias in CoO/Co multilayers deposited on nanostructured alumina templates. The increase in exchange bias and coercivity in the nanostructured films compared to non-patterned films indicates a change in magnetic anisotropy from in-plane to out-of-plane.
Article
Materials Science, Multidisciplinary
W. G. Zheng, V. Baledent, L. Bocher, A. Forget, D. Colson, P. Foury-Leylekian
Summary: In this study, an exchange bias effect with a large vertical shift in the field-cooled hysteresis loop was observed in the spin ladder system BaFe2Se3 below 50 K. The existence of uncompensated spins was evidenced by susceptibility, magnetic remanence, and hysteresis loop measurements. A nanometer-sized layered structure was also observed by scanning electron microscope (SEM) and confirmed by scanning transmission electron microscope (STEM) coupled with electron energy loss spectroscopy (EELS).
Article
Materials Science, Multidisciplinary
V. L. Kurichenko, D. Yu. Karpenkov, A. Yu. Degtyarenko
Summary: The exchange interaction between nanostructured components can enhance the magnetic properties of materials, which is utilized in exchange-coupled magnetic composites governed by constituent phases. Texturing is a challenge in utilizing such composites in industry. In this study, we investigated the exchange-bias properties in Co/Co3O4 nanocomposites based on nanorods array and found that the properties depend on the nanorods texture. Tailoring the texture can increase the exchange-bias field or enhance the material coercivity.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Tianle Zhang, Yujun Zhang, Mingyuan Huang, Bo Li, Yinghui Sun, Zhe Qu, Xidong Duan, Chengbao Jiang, Shengxue Yang
Summary: In this study, the exchange bias effect in Fe3GeTe2 (FGT)/CrOCl heterostructures is investigated through anomalous Hall effect (AHE) and reflective magnetic circular dichroism (RMCD) measurements. The exchange bias field (H-EB) is successfully tuned by changing the FGT/CrOCl thickness and the cooling field. A larger H-EB in RMCD measurements is observed, which is proposed to be related to the distribution of uncompensated spins at the interface.
Article
Chemistry, Multidisciplinary
Panluo Deng, Fengjun Zhuo, Hang Li, Zhenxiang Cheng
Summary: Researchers propose a method to create and transfer skyrmions using interlayer exchange coupling in hybrid ferromagnet/synthetic antiferromagnet structures. This approach eliminates the deviations in skyrmion transfer and allows for repeated creation of skyrmions in antiferromagnets. It provides a highly efficient approach for skyrmion-based data storage and logic devices.
Article
Materials Science, Multidisciplinary
Ravinder Kumar, S. N. Sarangi, D. Samal, Z. Hossain
Summary: Evidence of unprecedented room temperature positive exchange bias and hysteresis loop inversion has been found in monolithic Y3Fe5O12 films grown epitaxially on a (111)-oriented Gd3Fe5O12 crystal. The growth-induced interfacial layer coupling leads to positive EB and in-turn loop inversion, with a large exchange shift realized at 300 K. This discovery may have significant implications for spintronics device applications.
Article
Physics, Applied
Mohammad Hasan Jalali, Mohammad Hossein Shams, Hojjat Gholizadeh
Summary: Micromagnetic simulations were used to study the influence of shape on the magnetic permeability and loss tangent of Fe3O4 nanoparticles in the frequency range of 0.5 to 20 GHz. The study focused on 6 different shapes of Fe3O4 nanoparticles with equal volumes, divided into spherical particles and prismatic particles with a hexagonal base. The results showed that elongated particles generally had higher microwave magnetic permeability. Additionally, elongation decreased the resonance frequency in prismatic particles while increasing it in spherical ones. These findings are crucial for designing advanced microwave absorbers and predicting the effective permeability of composites containing magnetic nanoparticles.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2023)
Article
Physics, Applied
Min Xu, Jinyu Zhang, Dexiang Meng, Runshui Li
Summary: Different magnetic interactions and anisotropy have varying effects on the formation and morphology of skyrmions, with RKKY coupling playing a dominant role in generation and DMI affecting the shape. Heisenberg exchange and uniaxial anisotropy influence the diameter of skyrmions, and strong Heisenberg exchange and anisotropy can hinder skyrmion generation.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
Zhi Yang, Yuanyuan Chen, Weiqiang Liu, Yuqing Li, Liying Cong, Qiong Wu, Hongguo Zhang, Qingmei Lu, Dongtao Zhang, Ming Yue
Summary: This article investigates the effects of size, volume fraction, and surroundings of inhomogeneities on the magnetic properties of an inhomogeneous magnetic material through micromagnetic simulations, revealing the underlying magnetization reversal and coercivity mechanisms. Three different demagnetization characteristics are found depending on the size of inhomogeneities, and the increase in size leads to a transition of the coercivity mechanism from nucleation to pinning. This work could be useful for optimizing the magnetic properties of both exchange-coupled nanomagnets and inhomogeneous single-phase magnets.
Article
Physics, Applied
Janeth Alexandra Garcia-Monge, Arturo A. Ayon
Summary: Stress-dependent micromagnetic modeling based on the Landau-Lifshitz-Gilbert equations reveals the significant relationship between uniaxial stress in ferromagnetic thin films and pumped spin current density, influencing the static and dynamic magnetization. The ability to dynamically modulate the pumped spin current density through stress-mediated magnetoelectric coupling is anticipated to benefit various spintronic applications.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Applied
C. S. Kim, S. L. Ding, Y. J. O, L. Zha, C. Yun, W. Y. Yang, J. Z. Han, S. Q. Liu, H. L. Du, C. S. Wang, J. B. Yang
Summary: The study investigates the effects of microstructural factors on the performance of nanocomposite magnets through micromagnetic simulations. It reveals that the remanence is almost independent of the geometry of the soft phase, while coercivity decreases with increasing soft grain size. Additionally, a significant enhancement in energy product is observed with increasing soft grain size only when hard grain size is less than 15 nm.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Review
Chemistry, Inorganic & Nuclear
Gonzalo Vallejo-Fernandez, Markus Meinert
Summary: There is significant interest worldwide in identifying new antiferromagnetic materials suitable for device applications, with key requirements including high magnetocrystalline anisotropy constant, low cost, high corrosion resistance, and the ability to induce a large exchange bias. The novel antiferromagnetic material MnN shows potential as a replacement for the commonly used antiferromagnet IrMn, but further optimization is needed.
Article
Polymer Science
Al Mamun, Lilia Sabantina, Michaela Kloecker, Alexander Heide, Tomasz Blachowicz, Andrea Ehrmann
Summary: This paper presents a method for producing nanofiber mats containing different nanoparticles using electrospinning technique. Poly (acrylonitrile) (PAN) composite nanofiber mats with 50 wt% magnetite nanoparticles were electrospun and analyzed using SEM, AFM, EDS, and DMA. The results show that as the number of nanoparticles increases, the morphology and mechanical properties of the nanofiber mats decrease.
Article
Chemistry, Inorganic & Nuclear
Al Mamun, Michaela Kloecker, Tomasz Blachowicz, Lilia Sabantina
Summary: Electrospun magnetic nanofibers show great potential in various fields such as biomedicine, energy storage, filtration, and spintronics. This study presents a simple method for producing magnetic nanofiber mats by adding magnetic nanoparticles to an electrospun polymer solution. The distribution of nanoparticles in the fiber matrix and the chemical and morphological properties of the resulting magnetic nanofibers were investigated.
Article
Green & Sustainable Science & Technology
Fabian Schoden, Joscha Detzmeier, Anna Katharina Schnatmann, Tomasz Blachowicz, Eva Schwenzfeier-Hellkamp
Summary: This article discusses the urgent situation of resource crisis and the importance of renewable energy technologies. It mentions dye-sensitized solar cells as an emerging technology that can serve as an environmentally friendly and renewable energy solution. The research found that by remanufacturing old DSSCs, their lifespan can be extended and they can be rebuilt multiple times.
Proceedings Paper
Polymer Science
Tomasz Blachowicz, Jacek Grzybowski, Andrea Ehrmann
Summary: This paper investigates the distribution of magnetic nanoparticles in polymeric or other nonmagnetic matrices, and quantifies their influence on the magnetic properties of the composite materials through micromagnetic simulations.
MACROMOLECULAR SYMPOSIA
(2022)
Article
Polymer Science
Jan Lukas Storck, Guido Ehrmann, Uwe Gueth, Jana Uthoff, Sarah Vanessa Homburg, Tomasz Blachowicz, Andrea Ehrmann
Summary: While FDM and other inexpensive 3D printing methods are widely used, their application is limited due to mechanical and thermal constraints. The study found that filled PLA filaments are the most suitable material for high-temperature conditions.
Article
Materials Science, Multidisciplinary
Pawel Steblinski, Tomasz Blachowicz, Andrea Ehrmann
Summary: This article presents micro-magnetic simulations to analyze the energy density of nano-scaled iron spheres. The effects of different coatings and thicknesses on energy uniformity, as well as the relationship between droplet size and magnetization distribution, were investigated. The study reveals that oxide-coated spheres can be placed closer together in comparison to non-coated spheres.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Review
Polymer Science
Guido Ehrmann, Tomasz Blachowicz, Andrea Ehrmann
Summary: This article provides an overview of magnetic composites 3D-printed using different techniques and their potential applications. By embedding nanoparticles in the printing material, additional functionalities can be added to the objects. The influence of printing parameters on the magnetic and mechanical properties of these polymer/magnetic composites is also discussed.
Review
Green & Sustainable Science & Technology
Fabian Schoden, Anna Katharina Schnatmann, Tomasz Blachowicz, Hildegard Manz-Schumacher, Eva Schwenzfeier-Hellkamp
Summary: In a world where resources are in high demand and climate crisis is worsening, researching and implementing sustainable and regenerative products and processes becomes crucial. Dye-sensitized solar cells (DSSCs) are a promising technology that can be manufactured with low energy input and non-toxic components, while also being recyclable, repairable and remanufacturable. This publication explores appropriate design principles and business models for DSSC technology, with the key result being a performance-based business model that integrates DSSCs into the customer's building and provides green energy as a service.
Article
Multidisciplinary Sciences
Tomasz Blachowicz, Pawel Steblinski, Andrea Ehrmann
Summary: Magnetic nanofibers with varying lengths, cross-sections, and bending radii have unique magnetic properties and are intensively studied in simulations and experiments. They have potential applications in data storage, data transport, and spintronics devices. This study focuses on the influence of a constricted area with a rotating magnetic field on the magnetization dynamics of bent or straight magnetic nanofibers, revealing the strong impact of the area, nanofiber curvature, and Dzyaloshinskii-Moriya interaction.
Review
Materials Science, Multidisciplinary
Tomasz Blachowicz, Guido Ehrmann, Andrea Ehrmann
Summary: Additive manufacturing, or 3D printing, is a versatile technology that enables the creation of objects using various polymers, metals, and other materials in diverse shapes and sizes. By using corresponding feedstock, special physical or chemical properties can be achieved. Polymer composites with conductive properties are of particular interest in 3D printing, and this article provides an overview of recent developments in this area. It discusses the conductivity ranges, potential applications, additive manufacturing methods, and measurement techniques for these composites. The article also summarizes the latest reports on 3D printing of polymer composites with different conductive fillers and highlights the applications found in the literature.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Review
Biochemistry & Molecular Biology
Tomasz Blachowicz, Andrea Ehrmann
Summary: Electrospun nanofiber mats are commonly used in biotechnology or filtration due to their high specific surface area and small pore sizes. While they are typically white, their optical properties can be modified and become highly important in various applications such as sensing devices or solar cells.
Review
Materials Science, Multidisciplinary
Tomasz Blachowicz, Dariusz Wojcik, Maciej Surma, Miroslaw Magnuski, Guido Ehrmann, Andrea Ehrmann
Summary: Shielding of instruments and humans from electromagnetic interference (EMI) has become increasingly important. Textile fabrics with bendable, drapable, and stretchable EMI shielding properties are ideal for this purpose. However, conductivity and magnetic properties need to be added through conductive yarn, coatings, or fibers. Recent research has focused on MXenes due to their high conductivity and EMI shielding effectiveness, while other conductive and magnetic coatings and fibers are still promising for EMI shielding textile fabrics.
Article
Polymer Science
Al Mamun, Francisco Jose Garcia-Mateos, Lilia Sabantina, Michaela Kloecker, Elise Diestelhorst, Ramiro Ruiz-Rosas, Juana Maria Rosas, Jose Rodriguez-Mirasol, Tomasz Blachowicz, Tomas Cordero
Summary: In this study, electrospun carbon fiber electrodes were prepared for use as catalysts in the oxygen reduction reaction. The results showed that these catalysts exhibited good activity and selectivity.
Review
Materials Science, Multidisciplinary
Tomasz Blachowicz, Andreas Huetten, Andrea Ehrmann
Summary: This paper reviews recent advances in nanofiber mats for electromagnetic interference (EMI) shielding, focusing on their production, physical properties, and typical characterization techniques.
Article
Biotechnology & Applied Microbiology
Guido Ehrmann, Tomasz Blachowicz, Sarah Vanessa Homburg, Andrea Ehrmann
Summary: This review provides an overview of recent studies on the measurement of biosignals using single circuit boards, highlighting the new possibilities offered by devices like Arduino and Raspberry Pi in the mobile long-term acquisition of biosignals. The focus of the review is on the electronics, rather than textile electrodes.
BIOENGINEERING-BASEL
(2022)
