Article
Engineering, Multidisciplinary
S. Han Aydin
Summary: This study obtains numerical solutions for different problem configurations of 3-D Magneto-hydrodynamic (MHD) flow using a coupling approach of Boundary Element Method (BEM) and Finite Element Method (FEM) with stabilization. The results show the effects of problem parameters and configurations on the solutions, which are visualized as 2-D slices of the 3-D solutions.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2022)
Article
Automation & Control Systems
Dmitry Egorov, Ilya Petrov, Juha J. Pyrhonen, Joosep Link, Raivo Stern, Peter Sergeant, Bulent Sarlioglu
Summary: This study assesses the hysteresis behavior of two NdFeB PM grades with different magnetic properties in a PMSM. The results indicate that hysteresis loss resulting from structural imperfections and magnet geometry may introduce considerable loss in NdFeB PMs applied in rotating electrical machines.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Thermodynamics
Zhi Yong Ai, Jia Ming Ye
Summary: This paper proposes a method for the thermo-mechanical analysis of pipe energy piles in layered cross-anisotropic soils. The pipe pile is modeled as a bar and the stiffness matrix equation considering thermo-mechanical loads is established using the finite element method (FEM). The soils are considered to be layered cross-anisotropic and the boundary element method (BEM) is employed to obtain the deformation-force relationship of the soil-pile nodes. The method is verified with responses of different types of piles and parametric analyses reveal important design considerations for pipe energy piles.
Article
Materials Science, Multidisciplinary
Behrooz Rezaeealam
Summary: This paper introduces a new hybrid method of finite element method-boundary element method for transient analysis of hysteresis motor, which considers the eddy current effect in the rotor region for the first time, addressing issues in traditional models. The study demonstrates that the proposed model outperforms traditional models in analyzing the phenomenon of over-excitation in hysteresis motors.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Mathematics, Applied
Timo Betcke, Michal Bosy, Erik Burman
Summary: In this paper, a hybrid method for FEM-BEM coupling is discussed. The coupling from both sides uses a Nitsche-type approach to couple to the trace variable. This leads to a formulation that is robust and flexible, and can easily be combined with other hybrid methods.
NUMERICAL ALGORITHMS
(2022)
Article
Energy & Fuels
Saud Alshammari, Panos Lazari, Kais Atallah
Summary: The article investigates the use of permanent magnet eddy current couplings for high efficiency power transmission. Simulation studies compare the performance of radial- and axial-field topologies with squirrel cage and conducting sheets in terms of torque transmission density and efficiency. The results show that using a squirrel cage is more suitable for high efficiency power transmission, despite a higher torque transmission density with conducting sheets. A prototype of a radial-field single sided permanent magnet eddy current coupling with a copper squirrel cage is developed and tested, demonstrating good agreement between measurements and predictions.
IEEE TRANSACTIONS ON ENERGY CONVERSION
(2023)
Article
Engineering, Geological
Yang Li, Zhi Yong Ai
Summary: This study investigates the horizontal transient response of partially embedded pile groups in multilayered transversely isotropic soils using the FEM and compares the results with existing literature. Numerical examples are provided to explore how various factors such as free-standing length, pile-soil stiffness ratio, pile spacing ratio, soil's transverse isotropy, and stratification affect the horizontal transient response of partially embedded pile groups.
Article
Engineering, Geological
Zi Ye, Zhi Yong Ai
Summary: This paper investigates the dynamic response of a pile embedded in layered transversely isotropic unsaturated soils subjected to a vertical external excitation. The triphasic model is used to simulate the unsaturated media more realistically, and the BEM-FEM coupling method is employed to obtain the soil-pile interaction formulation. The correctness of the proposed theory is verified, and further parametric studies are conducted to discuss the influences of various factors on the dynamic behavior of the pile.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2022)
Article
Mathematics, Applied
Weidong Lei, Xiaofei Qin, Hongjun Li, Youhua Fan
Summary: This paper proposes an iterative decomposition coupling algorithm between time-domain FEM and time-domain BEM with independent spatial discretization on the interface. Data exchange on the interface is achieved through converting matrices, freeing from the limitation of interpolation calculation for variables. The proposed algorithm shows good versatility and computational efficiency.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Engineering, Multidisciplinary
Hrvoje Dodig, Dragan Poljak, Mario Cvetkovic
Summary: This article presents the correct coupling of edge element BEM with edge element FEM, showing that it is simpler and easier to implement compared to MoM/FEM. The method performs well in scattering problems involving objects with sharp corners.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
A. Urdaneta-Calzadilla, N. Galopin, I. Niyonzima, O. Chadebec, B. Bannwarth, G. Meunier
Summary: This paper presents a numerical modeling approach for devices based on magnetoelectric composite materials. The mechanical combination of piezoelectric and magnetostrictive materials in these heterogeneous structures results in magneto-electric effects that are several orders of magnitude higher than single-phase multiferroic materials. The Finite Element Method (FEM) and Boundary Element Method (BEM) are coupled to effectively model the behavior of magnetic effects, while classical FEM formulations are used for electrical and mechanical problems. This coupled numerical approach allows for a reduction in the number of unknowns and shorter computation times compared to a pure FEM approach, and the final system of equations is solved using a block Gauss-Seidel type solver.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Energy & Fuels
Jinqiao Chen, Shuang Wang, Huidong Shang, Heng Hu, Tao Peng
Summary: This paper proposes an effective method to model axial flux permanent magnetic hysteresis damper (APHD) and achieves fast identification of JA hysteresis model parameters using numerical method and genetic algorithm. By comparing the measured and calculated hysteresis curves, the high accuracy and efficiency advantages of this method are proven. The study analyzes the influence of eddy current, dimensional parameters, and magnetization proportion on the output torque of APHD, and verifies the reliability of simulation results through prototype testing.
IEEE TRANSACTIONS ON ENERGY CONVERSION
(2022)
Article
Chemistry, Multidisciplinary
Iratxo Gomez, Gustavo Garcia, Alex McCloskey, Gaizka Almandoz
Summary: The article discusses the main sources of noise and vibration in electrical machines, the torque density advantages of permanent-magnet synchronous machines, and the relationship between electromagnetic forces and design variables. Through analytical modeling and experimental tests, the results obtained show good agreement with both FEM results and experimental measurements.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Multidisciplinary
Daho Boumaiza, Benaoumeur Aour
Summary: The paper investigates the interface relaxation FEM-BEM coupling method for solving problems involving nonlinear fracture mechanics. The method employs finite element method (FEM) to model the nonlinear portion near the crack tip and boundary element method (BEM) to discretize the linear elastic domain. The coupling procedure utilizes successive variable renewal on the interface without combining the coefficient matrices of FEM and BEM subdomains. Several practical problems are analyzed to demonstrate the effectiveness of the approach, and a critical comparison is made with conventional FEM computations.
JOURNAL OF FAILURE ANALYSIS AND PREVENTION
(2022)
Proceedings Paper
Computer Science, Interdisciplinary Applications
Maxime Fays, Olivier Chadebec, Brahim Ramdane
Summary: An original magnetic scalar potential FEM-BEM coupling based on isogeometric analysis is proposed to tackle magnetostatic problems. The efficiency of the method is demonstrated through tests performed on an academic problem and a more complex multipatch geometry.
TWENTIETH BIENNIAL IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (IEEE CEFC 2022)
(2022)
Article
Materials Science, Multidisciplinary
Alexander Kovacs, Lukas Exl, Alexander Kornell, Johann Fischbacher, Markus Hovorka, Markus Gusenbauer, Leoni Breth, Harald Oezelt, Dirk Praetorius, Dieter Suess, Thomas Schrefl
Summary: Physics informed neural networks can be used to solve partial differential equations and variational problems related to magnetic fields, by approximating the unknown field with neural networks. This method can be applied to estimate magnetic flux density, solve inverse magnetostatic problems, and address micromagnetic problems.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
S. Perna, F. Bruckner, C. Serpico, D. Suess, M. d'Aquino
Summary: This paper proposes a new method for micromagnetic simulations, using normal modes to describe the dynamics of magnetic nanostructures and optimize the system response to external excitations. The validity and computational speed of this method are demonstrated through case studies in different scenarios.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
S. Perna, F. Bruckner, C. Serpico, D. Suess, M. D'Aquino
Summary: The spatially-inhomogeneous magnetization dynamics in a cylindrical magnetic nanodot driven by ac spin-torque is analyzed. The Landau-Lifshitz-Gilbert-Slonczewski equation is reformulated as a system of coupled nonlinear ordinary differential equations describing the time-evolution of normal modes amplitudes. This approach provides a class of models with reduced degrees of freedom and incremental accuracy between macrospin and full micromagnetics.
Article
Physics, Applied
Zachary R. Nunn, Juliana Besler, Pavlo Omelchenko, Sabri Koraltan, Claas Abert, Dieter Suess, Erol Girt
Summary: We demonstrate that a noncollinear alignment between magnetizations of adjacent ferromagnetic layers can be achieved by coupling two ferromagnetic layers across a magnetic spacer layer consisting of a nonmagnetic material, Ru, alloyed with a ferromagnetic element, Co. The relative angle between the magnetizations of the ferromagnetic layers can be controlled by changing the composition and thickness of the spacer layer between 0 degrees and 180 degrees.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
D. Suess, S. Koraltan, F. Slanovc, F. Bruckner, C. Abert
Summary: Within this paper, we demonstrate the significance of accurate implementations of RKKY interactions for antiferromagnetically coupled ferromagnetic layers with thicknesses larger than the exchange length. We develop a benchmark problem to evaluate different implementations of RKKY interaction by deriving an analytical formula for the saturation field of two infinitely thick antiparallelly coupled magnetic layers. Our benchmark problem reveals that current implementations in commonly used finite-difference codes lead to errors in the saturation field, exceeding 20% for mesh sizes of 2 nm, which is below the material's exchange length. To enhance accuracy, we introduce higher order cell-based and nodal-based finite-difference codes that significantly reduce errors compared to existing implementations. With a mesh size of 2 nm, the second-order cell-based approach and the first-order nodal-based approach reduce the error in the saturation field by a factor of 10 (2% error).
Article
Materials Science, Multidisciplinary
Santiago Helbig, Claas Abert, Pedro A. Sanchez, Sofia S. Kantorovich, Dieter Suess
Summary: We propose a simple simulation model to study magnetic and frictional losses of magnetic nanoparticles in viscous fluids under alternating magnetic fields. The model is based on a macrospin approach and solves the Landau-Lifshitz-Gilbert equation coupled with the mechanical torque equation. Despite its simplicity, the model reveals rich physics and allows for a detailed analysis of different loss processes depending on field parameters and initial particle-field arrangement. The model demonstrates the emergence of different steady states depending on these parameters, with regions dominated by magnetic relaxation and high losses or high frictional losses at low fields or frequencies. The energy continuously increases even across regime boundaries, surpassing the viscous relaxation limit. At higher frequencies, the steady state can also depend on the initial particle orientation in the external field. We compare and discuss the general behavior and specific absorption rates for different cases.
Article
Materials Science, Multidisciplinary
A. Troster, J. Pils, F. Bruckner, W. Schranz, I. Rychetsky, C. Verdi
Summary: This study investigates the emergence of polarity in so-called hard antiphase boundaries in strontium titanate using atomistic simulations and numerical solutions. Traditional numerical solutions fail to reproduce the shape and pressure behavior of the domain wall polarization, but adding rotopolar couplings and considering nuclear quantum fluctuations can restore semiquantitative agreement.
Article
Materials Science, Multidisciplinary
Sabri Koraltan, Claas Abert, Florian Bruckner, Michael Heigl, Manfred Albrecht, Dieter Suess
Summary: In this study, we demonstrate the controlled generation and annihilation of (anti)skyrmions with tunable chirality in magnetic heterostructures through micromagnetic simulations. The stability of the (anti)skyrmion depends on the polarization of the (anti)vortex, while their chirality is determined by the (anti)vortices. We also predict that the same coupling mechanism works for chiral skyrmions by introducing the interlayer Dzyaloshinskii-Moriya interaction. Furthermore, we show that the core coupling between the (anti)vortices and (anti)skyrmions allows controlled deletion and writing of spin objects.
Article
Materials Science, Multidisciplinary
Claas Abert, Sabri Koraltan, Florian Bruckner, Florian Slanovc, Juliana Besler, Pavlo Omelchenko, Erol Girt, Dieter Suess
Summary: This study presents a simple atomistic model to describe noncollinear coupling in magnetic multilayers. The model accurately predicts the dependence of coupling constants on the spacer-layer composition and thickness, and validates the independence of noncollinear coupling on the exchange stiffness in the ferromagnetic layers.
Article
Multidisciplinary Sciences
Gregor Wautischer, Claas Abert, Florian Bruckner, Florian Slanovc, Dieter Suess
Summary: This work investigates the possibility of reducing transition curvature in heat-assisted magnetic recording by shaping the recording field. The topology optimization of the head tip is performed to create the desired cross-track field profile. The results show that shaping the field profile alone does not necessarily lead to an improvement in the read-back process.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Multidisciplinary
Sebastian Deussner, Dieter Suess, Claas Abert, Florian Bruckner, Sebastian Faehler, Paul Heistracher, Ludwig Reichel, Volker Neu
Summary: This paper investigates the formation of stripe domains in thin films with perpendicular anisotropy and explores the dependence of stripe domain width on film thickness. Analytical models and simulations are used to analyze the experimental data and provide a benchmark for future studies.
Article
Materials Science, Multidisciplinary
Bibhutibhusan Nayak, S. Narayana Jammalamadaka
Summary: This article presents a method for remote detection of bovine serum albumin (BSA) using modified cantilever beam magnetometry (CBM). By combining a magnetostrictive Fe70Ga30 cantilever with optical detection technique, researchers were able to detect high concentrations of BSA remotely. The results of this study demonstrate the potential of this method in estimating the magnetostriction of thin films.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yu Hao, R. E. Camley, Z. Celinski
Summary: Magnetic particles have various applications and their magnetic state is determined by their size and the strength of an applied magnetic field. Numerical simulations were performed to study the effect of an applied field on the critical size of single-domain magnetic particles, and the critical field at which a particle becomes single-domain was determined.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Nitesh Singh, Naresh Kumar, Dharohar Sahadot, Anil Annadi, Vidyadhar Singh, Murtaza Bohra
Summary: The unique magnetic properties of FM/AFM and hard-FM/soft-FM nanocomposite thin films have significant relevance for numerous applications. The composition and performance of different magnetic phases in the nanocomposite films can be significantly affected by the laser ablation conditions and annealing temperature.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Alya Ali Musaed, Samir Salem Al-Bawri, Khaled Aljaloud, Wazie M. Abdulkawi, Mohammad Tariqul Islam, Mandeep Jit Singh, Zaini Sakawi, Husam Hamid Ibrahim
Summary: This research presents a wideband tunable metamaterial for body-centric applications in the millimeter-wave frequency band. The proposed metamaterial has a wide operating frequency range and enhanced gain, making it suitable for improving the antenna performance in 5G wireless communication systems.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Binod K. Rai, Boris Maiorov, Krzysztof Gofryk, Patrick O'Rourke, Catherine Housley, Henry Ajo, Asraf Sawon, Arjun K. Pathak, Narayan Poudel, Qiang Zhang, Travis J. Williams, Matthias Frontzek
Summary: This manuscript reports on the structural and magnetic properties of NdCuGa3. The study confirmed the crystal structure and magnetic phase transition of NdCuGa3 using XRD, neutron diffraction, magnetization, and specific heat measurements. The neutron diffraction data further confirmed the antiferromagnetic phase of NdCuGa3.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Haonan Li, Cong Li, Hailiang Huang, Guodong Hao, Fei Wang
Summary: The electronic structure and ferroelectric-ferromagnetic coupling properties of Y-doped and vacancy-containing GaN-ZnO heterojunctions are systematically investigated. The magnetism in vacancy-containing systems is generated by the spin polarization of unpaired electrons induced by cationic vacancies, while in Y-doped systems, bound magnetic polarons are formed by the orbital hybridization of s-state and d-state electrons of Y-doped elements.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Muhammad Ijaz, Hafeez Ullah, Bandar Ali Al-Asbahi, Mati Ullah Khan, Zaheer Abbas, Sana Ullah Asif
Summary: M-type BaFe11.4-xAlxCo0.6O19 hexaferrites with Al3+ substitutions were synthesized using the co-precipitation method followed by Sonochemical process. The synthesized materials were characterized using XRD, FTIR, UV-vis spectroscopy, VSM, SEM, and LCR meter. The results showed that aluminum doping decreased the band gap and enhanced the magnetic and dielectric properties of the hexaferrites, making them suitable for various applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Oleg I. Utesov
Summary: The elementary excitations spectrum of anisotropic frustrated antiferromagnets in the fan phase is discussed. It is found that the low-energy part of the spectrum consists of a gapless phason branch with linear dispersion and a gapped optical branch corresponding to the fan structure amplitude oscillations. In the high-energy part of the spectrum, the excitations are similar to the magnons of the fully polarized phase.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Alexander Ya. Simonovskii, Alexander A. Yanovskii, Arthur R. Zakinyan
Summary: In this study, the departure frequency of vapor bubbles during boiling of ferrofluid in a horizontal magnetic field is experimentally investigated. Two methods, visual and inductive, are used to measure the frequency of bubble departure. The results show that the bubble departure frequency can decrease with increasing magnetic field strength and increase with increasing temperature of the heat-emitting surface. A linear stability analysis is conducted to analyze the influence of the magnetic field on the frequency of bubble formation during ferrofluid boiling.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Oleg Heczko, Michal Rames, Vit Kopecky, Petr Vertat, Michal Varga, Ladislav Straka
Summary: Heusler Ni-Mn-Ga alloys are multiferroic materials that exhibit magnetic shape memory (MSM) phenomena. By doping transition elements into Ni2MnGa alloys, the transformation temperatures can be modified and complex behaviors can be observed, such as the variation in saturation magnetization and the effects of elemental substitution on compound properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Carlos Ariel Samudio Perez, Ariel Flaig de Marchi
Summary: This study investigates the electronic and magnetic properties of the Full-Heusler Fe2MnAs alloy using first-principles calculations. The alloy may form spontaneously and exhibits a ferromagnetic order and high spin-polarization. It can be transformed into a half-metal by contracting the lattice constant. Additionally, certain defects contribute to the spin-polarization of the alloy, making it a fully half-metallic material.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Satish Geeri, Aditya Kolakoti, Prasadarao Bobbili
Summary: In this study, an electromagnetic wave-absorbing material was fabricated using a polymer composite material with fiber orientation and Multiwall Carbon Nanotubes as filler materials, along with a Perfect Electric Conducting material. The experiments demonstrated strong electromagnetic absorbing properties for the composites with PEC-coated and non-PEC-coated materials. Mechanical, thermal, and morphological analysis confirmed the similar trend in properties. CRITIC analysis helped identify the sequence order of sustaining properties for the fabricated composites.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yankai Chen, Ruoxue Zhang, Yukai An
Summary: The piezoelectricity, valley character, and magnetic properties of 2H-VS2 monolayer were studied, revealing its potential applications in spintronics and valleytronics due to its bipolar magnetic semiconductor characteristics and superior physical properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Leonardo S. Lima
Summary: This study investigates the thermodynamic quantities, such as entropy, specific heat, and magnetic susceptibility, in the next-nearest-neighbors Heisenberg model on a honeycomb-kagome lattice. The linear spin-wave approach is applied to obtain the temperature-dependent behavior of these quantities. Additionally, the entanglement negativity, a quantifier of quantum entanglement, and the spin Hall conductivity are also studied. The results show that all the thermodynamic quantities, as well as the entanglement negativity and spin Hall conductivity, exhibit an increasing trend with temperature. Furthermore, it is found that all the analyzed quantities approach zero in the low-temperature limit, consistent with experimental observations.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Zhaoxing Wang, Maximilian Kai Reimann, Wang Chen, Yikun Zhang, Rainer Poettgen
Summary: The Mo2FeB2-type compounds RE2Ga2Mg (RE = Tm, Er, Ho) exhibit a large magnetocaloric effect, making them promising for cryogenic magnetic cooling applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2024)
