Article
Engineering, Electrical & Electronic
Hikaru Yamane, Simon John Greaves, Yoichiro Tanaka
Summary: Modeling heat-assisted magnetic recording on bit patterned media dots with two magnetic structures showed that storing two bits of information in each dot is possible. The areal density capability of the dual structure media was calculated to exceed 7 Tbit/in(2) despite dot position distributions and magnetostatic fields from surrounding dots.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Chemistry, Analytical
Pirat Khunkitti, Naruemon Wannawong, Chavakon Jongjaihan, Apirat Siritaratiwat, Anan Kruesubthaworn, Arkom Kaewrawang
Summary: This study introduces exchange-coupled composite bit-patterned media (ECC-BPM) combined with microwave-assisted magnetic recording (MAMR) to enhance the writeability of magnetic media at a recording density of 4 Tb/in^2. By evaluating the suitable microwave field frequency and exchange coupling values between magnetic dots in the proposed media, significant reductions in switching field were achieved compared to conventional media, further decreased by utilizing MAMR technology.
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Bit-patterned media recording (BPMR) is a promising technology for increasing the areal density (AD) of magnetic data storage systems. In this study, the maximum a posteriori (MAP) algorithm is proposed to improve the serial detection method and address the issues of 2D interference and track mis-registration (TMR) in BPMR.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Hikaru Yamane, Simon John Greaves, Yoichiro Tanaka
Summary: Dual structure bit patterned media were optimized for heat-assisted magnetic recording (HAMR) to store two bits of information in each dot. The optimized design included a thicker recording structure on the bottom and a thinner structure on the top, based on analysis of thermal stability. Recording simulations showed potential for user areal recording densities beyond 9 Tbit/in(2).
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Engineering, Electrical & Electronic
Pierre-Olivier Jubert, Tiffany Santos, Thanh Le, Burak Ozdol, Cristian Papusoi
Summary: The study explores the relevance of anisotropic heatsinks for HAMR, finding that their performance is determined by in-plane thermal conductivity. TDTR measurements extracted the thermal conductivities of a (Cu/Ta) multilayer heatsink, demonstrating its potential as a candidate for HAMR with high in-plane thermal conductivity.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Chemistry, Multidisciplinary
Seongkwon Jeong, Jaejin Lee
Summary: This study proposes a modulation decoding method based on the K-means algorithm to improve decoding capabilities in bit-patterned media recording systems. Increasing the areal density makes it more difficult to detect data due to the influence of intersymbol interference (ISI) and intertrack interference (ITI), but modulation coding can prevent severe ISI and ITI caused by specific data patterns.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Gyuyeol Kong, Minchae Jung
Summary: This paper proposes a tabu search aided multi-track detection scheme for bit patterned magnetic recording. The proposed scheme adopts a simplified multi-track detector with a two-dimensional generalized partial response target, uses a priori information, and employs a reliability test and a tabu search detector. The proposed scheme processes signals in three stages, and achieves better performance compared to conventional schemes.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Seongkwon Jeong, Jaejin Lee
Summary: This study investigates the electronic structure and magnetic properties of potential two-dimensional material MnPS3 using density functional theory. The results reveal its semiconductor nature and antiferromagnetic properties, providing a theoretical basis for its applications in electronic and magnetic devices.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Seongkwon Jeong, Jaejin Lee
Summary: In this study, a bit-flipping scheme using the K-means algorithm for bit-patterned media recording (BPMR) system is proposed to increase the areal density of hard disk drives. The scheme reduces the distance between islands storing 1 bit and utilizes neighboring information to improve performance.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Nanoscience & Nanotechnology
S. Sokjabok, M. Mattayakan, C. Buajong, S. Koonkarnkhai, P. Kovintavewat, C. Warisarn
Summary: The reduction in track width of ultra-high density magnetic recording leads to an increase in areal density, but also brings about severe inter-symbol interference and inter-track interference. To address these issues, a single-reader/two-track reading technique and constrained coding schemes are proposed, showing superior performance in mitigating ISI and ITI effects compared to conventional systems.
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Bit-patterned media recording (BPMR) is proposed as a candidate solution for addressing superparamagnetism issues in magnetic data storage. This study focuses on reducing the distance between magnetic islands in BPMR to increase the areal density, while also addressing the increased two-dimensional interference. A new estimator based on the 2D Viterbi algorithm (VA) with reduced states is proposed to predict interference from neighboring tracks. Simulation results demonstrate the superiority of this model compared to previous models.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Thien An Nguyen, Jaejin Lee
Summary: Ultra-high density data storage, specifically using bit-pattern media recording (BPMR), is crucial due to the increasing volumes of data. A neural network model for noise prediction has been proposed to improve the performance of serial detection, resulting in approximately 1 dB gain in bit error rate (BER) compared to the model with a feedback line.
APPLIED SCIENCES-BASEL
(2021)
Article
Computer Science, Information Systems
Thien An Nguyen, Jaejin Lee
Summary: This article examines a new distribution of bit-patterned media recording called staggered BPMR. By dividing the interference into three parts and using three one-dimensional detectors, the proposed model improves the detection performance of the main data. Simulation results demonstrate that this model outperforms previous studies.
Article
Physics, Multidisciplinary
Wei Chen, Jincai Chen, Zongsong Gan, Yaxiong Ma, Ke Luo, Zhenxing Huang, Yang He, Ping Lu
Summary: The semi-circle resonator system proposed as the light delivery system for HAMR can provide a stable enhanced optical field to excite the localized surface plasmon of NFT without complex focusing lenses or external controls. Combined with bit-patterned media, the performance can be improved several times than the thin-film structure.
Article
Engineering, Electrical & Electronic
Seongkwon Jeong, Jaejin Lee
Summary: The study proposes using extrinsic information obtained from an MLP equalizer to improve the detection performance of BPMR in PRML detector, showing better performance compared to both MLP equalizer and conventional PRML alone. The proposed detector also provides improved performance when track misregistration occurs.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Chemistry, Physical
Jiyuan Li, Xikai Jiang, Abhinendra Singh, Olle G. Heinonen, Juan P. Hernandez-Ortiz, Juan J. de Pablo
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Multidisciplinary
Peng Li, Jinjun Ding, Steven S-L Zhang, James Kally, Timothy Pillsbury, Olle G. Heinonen, Gaurab Rimal, Chong Bi, August DeMann, Stuart B. Field, Weigang Wang, Jinke Tang, Jidong Samuel Jiang, Axel Hoffmann, Nitin Samarth, Mingzhong Wu
Summary: This study reports a genuine topological Hall effect in a TI/MI structure, where the contribution of skyrmions to the Hall effect outweighs the coexistence of magnetic phases.
Article
Materials Science, Multidisciplinary
Hyeondeok Shin, Jaron T. Krogel, Kevin Gasperich, Paul R. C. Kent, Anouar Benali, Olle Heinonen
Summary: By utilizing highly accurate quantum Monte Carlo methods, we have successfully determined the chemical structure and electronic band gaps of monolayer GeSe. Our findings indicate that the optimized structure and calculated band gaps of monolayer GeSe differ from those obtained using DFT methods.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Multidisciplinary Sciences
Zhengtao Gan, Orion L. Kafka, Niranjan Parab, Cang Zhao, Lichao Fang, Olle Heinonen, Tao Sun, Wing Kam Liu
Summary: Identifying scaling laws in metal 3D printing is crucial for process optimization and materials development. By using high-speed synchrotron X-ray imaging and multiphysics modeling, the authors report scaling laws to quantify the correlation between process parameters, keyhole stability, and pore formation.
NATURE COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Tyler N. Pardue, Manik Goyal, Binghao Guo, Salva Salmani-Rezaie, Honggyu Kim, Olle Heinonen, Michelle D. Johannes, Susanne Stemmer
Summary: Epitaxial strains can induce unique topological states in thin films and heterostructures, as demonstrated in Cd3As2 films where different point group symmetries are observed under various biaxial stress conditions, indicating tunable electronic structures under external forces.
Article
Materials Science, Multidisciplinary
C. Lei, O. Heinonen, A. H. MacDonald, R. J. McQueeney
Summary: The study used classical Monte Carlo simulations and electronic structure models to calculate the ground state magnetic phase diagram, topological and optical properties of MBT films, finding that it is possible to prepare a variety of different magnetic stacking sequences, some of which have sufficient symmetry to disallow nonreciprocal optical response and Hall transport coefficients.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Chemistry, Physical
Daniel Staros, Guoxiang Hu, Juha Tiihonen, Ravindra Nanguneri, Jaron Krogel, M. Chandler Bennett, Olle Heinonen, Panchapakesan Ganesh, Brenda Rubenstein
Summary: In this study, the structural, electronic, and magnetic properties of monolayer CrI3 are predicted using Density Functional Theory (DFT) and high-accuracy Diffusion Monte Carlo (DMC) simulations. The results show that DFT predictions of magnetic spin moments in monolayer CrI3 are on average correct but miss critical local spatial fluctuations in the spin density revealed by the more accurate DMC. Moreover, substantial spin-phonon coupling is observed in monolayer CrI3.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Thais Trevisan, Pablo Villar Arribi, Olle Heinonen, Robert-Jan Slager, Peter P. Orth
Summary: Bicircular light is shown to be a versatile method for controlling magnetic symmetries and topology in materials. Using a low-energy model, Cd3As2 is theoretically demonstrated as a promising platform for BCL Floquet engineering, which can induce a transition to a noncentrosymmetric magnetic Weyl semimetal phase. With strain, a magnetic topological crystalline insulator with unique unpinned surface Dirac states can be predicted, protected by a combination of twofold rotation and time reversal symmetries and controllable by light.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
O. Heinonen, R. A. Heinonen, H. Park
Summary: The recently discovered triangular antiferromagnet CoNb3S6 has shown a large anomalous Hall effect due to its interesting magnetic structure that interacts with the electronic structure. A proposed model reveals various ground states, including planar and nonplanar spin spirals, as well as a distinct noncoplanar 3q state, which can exhibit a nonzero anomalous Hall effect.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Wenku Wu, Ursula R. Kattner, Carelyn E. Campbell, Jonathan E. Guyer, Peter W. Voorhees, James A. Warren
Summary: Cobalt-based superalloys with two phase gamma/gamma ' microstructures show great promise for next-generation high-temperature alloys. Understanding the thermodynamic and kinetic factors that influence the microstructural evolution is crucial for optimizing their performance.
Article
Physics, Multidisciplinary
N. S. Bingham, X. Zhang, J. Ramberger, O. Heinonen, C. Leighton, P. Schiffer
Summary: In this study, we investigated the temperature and magnetic field dependence of the total magnetic moment of large-area permalloy artificial square spin ice arrays. Our findings showed that the hysteresis behavior and temperature dependence are consistent with the Stoner-Wohlfarth model, with deviations observed at small lattice spacing due to interisland interactions. Through micromagnetic simulations, we further explored the complex magnetization reversal induced by interisland interactions, highlighting the critical role of island shapes in tuning the physical properties of artificial spin ice structures and other nanomagnet systems.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Jovan Nelson, Teodor K. Stanev, Dmitry Lebedev, Trevor LaMountain, J. Tyler Gish, Hongfei Zeng, Hyeondeok Shin, Olle Heinonen, Kenji Watanabe, Takashi Taniguchi, Mark C. Hersam, Nathaniel P. Stern
Summary: Layer-dependent optical spin dynamics have been observed in few-layer and bulk InSe, indicating the potential for all-optical excitation and control of spin in this material.
Article
Materials Science, Multidisciplinary
John Mangeri, Davi Rodrigues, Monica Graf, Sudipta Biswas, Olle Heinonen, Jorge Iniguez
Summary: This paper proposes a continuum approach to study the magnetoelectric multiferroic BiFeO3, combining the ferroelectric phase field method and micromagnetic simulations. The modeling effort allows for the self-consistent description of the different order parameters on the same scale. The model is used to analyze the domain wall topology and the influence of FE domain boundaries on magnetic domain walls, as well as to simulate spin-wave transmission and magnetoelectric switching. The study provides insights for further research on nanostructures of BFO at the mesoscale.
Article
Physics, Multidisciplinary
Gaurav Chaudhary, Anton A. Burkov, Olle G. Heinonen
Summary: This study finds that twisted bilayers of thin film magnetic topological insulators with large in-plane magnetization can realize flat bands near 2D Dirac nodes. By changing the in-plane magnetization, the band dispersion of the twisted bilayer can be tuned to quadratic band touching or flat bands, similar to twisted bilayer graphene. This finding is important for studying strongly correlated phases of 2D Dirac semimetals.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Eric B. Isaacs, Hyeondeok Shin, Abdulgani Annaberdiyev, Chris Wolverton, Lubos Mitas, Anouar Benali, Olle Heinonen
Summary: The study utilized many-body quantum Monte Carlo method to calculate the formation energy of two compounds, showing discrepancies with standard density functional theory predictions.
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)
