Article
Materials Science, Multidisciplinary
Juan A. Ramos-Guivar, R. Soria-Martinez
Summary: This research focuses on simulating Gd, Ni, and Ni-Gd core-shell magnetic nanosystems using VAMPIRE software and the Landau-Lifshitz-Gilbert-Heun approach. Temperature dependent magnetization curves were generated to estimate the Curie temperature. Simulations at different particle diameters revealed critical values where the T-c values deviate from the theoretical bulk values. FCC and HCP structure configurations showed similar behaviors at large particle sizes. The magnetic properties can be tuned by varying the core diameter of the Ni-Gd core-shell nanosystem, and antiferromagnetic coupling plays a significant role in the M-T curves and spin distributions.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sun-Woo Kim, Jae Chul Ro, Su-Jeong Suh
Summary: Ni/Ni3C core-shell nanoparticles with an average diameter of approximately 120 nm were synthesized via a chemical solution method. It was observed that a thin Ni3C shell measuring approximately 1-4 nm formed on the surface of the nanoparticles over time, and the Ni core consisted of multiple grains. The saturation magnetization of the core-shell nanopowders decreased in proportion to the amount of Ni3C. The synthesis mechanism of the Ni/Ni3C core-shell nanoparticles was proposed based on XRD, XPS, and TEM analyses.
Article
Chemistry, Multidisciplinary
Jeongeon Kim, Xenia Medvedeva, Jury J. Medvedev, Cheongwon Bae, Juyeong Kim, Anna Klinkova
Summary: Understanding the relationship between structure and performance in nanoscale electrocatalysts for urea electrolysis is important for efficient waste treatment and hydrogen production or CO2 reduction. We investigate the role of lattice strain in Pd-Ni core-shell nanocubes on the dominance of the urea overoxidation pathway.
Article
Engineering, Environmental
Hongsheng Li, Song Gao, Hanxiang Tong, Yanling Liu, Aimin Wu, Huang Hao
Summary: In this study, a series of Ni@SiC@C double-shell nanoparticles were synthesized by modulating the concentration of methane. The double-shell structure, consisting of a Ni core, SiC dielectric material, and graphite shells, effectively increased the polarization source and improved the dielectric and electromagnetic wave absorption properties. The study provides insights into the working mechanism of the new absorbing material and demonstrates the effectiveness of double-shell structures in enhancing the potential of absorbing devices.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Xichen Zhou, Yangbo Ma, Yiyao Ge, Shangqian Zhu, Yu Cui, Bo Chen, Lingwen Liao, Qinbai Yun, Zhen He, Huiwu Long, Lujiang Li, Biao Huang, Qinxin Luo, Li Zhai, Xixi Wang, Licheng Bai, Gang Wang, Zhiqiang Guan, Ye Chen, Chun-Sing Lee, Jinlan Wang, Chongyi Ling, Minhua Shao, Zhanxi Fan, Hua Zhang
Summary: The Au@Pd core-shell nanorods with a unique fcc-2H-fcc heterophase exhibit superior electrocatalytic ethanol oxidation performance, contributing to insights into the catalytic mechanism. The exceptional performance of the heterophase Au@Pd nanorods is attributed to the unconventional 2H phase, the 2H/fcc phase boundary, and the lattice expansion of the Pd shell.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
J. Mohapatra, J. Elkins, M. Xing, D. Guragain, Sanjay R. Mishra, J. Ping Liu
Summary: Self-assembly of nanoparticles can lead to the formation of new materials with desired physical properties. In this study, composition-modulated bimagnetic nanoparticles were used to produce ordered structures with enhanced magnetic properties, such as anisotropy and remanent magnetization. The presence of magnetic fields during assembly played a key role in the formation of oriented nanoparticle chains in superlattice structures.
Article
Chemistry, Multidisciplinary
Ajit Kumar Singh, Seulgi Ji, Baghendra Singh, Chittaranjan Das, Heechae Choi, Prashanth W. Menezes, Arindam Indra
Summary: The Mott-Schottky catalyst Co@NC demonstrates excellent oxygen evolution activity and long-term stability by entrapping cobalt nanoparticles inside the N-doped graphene shell. The synergy between hcp and fcc cobalt, along with the optimization from the NC shell, plays a major role in improving the catalytic activity.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Lizhen Hou, Xing Zhen, Linlin Liu, Daitao Kuang, Yangyang Gao, Heng Luo, Lianwen Deng, Chuansheng Chen, Shiliang Wang
Summary: This study presents a one-step method for synthesizing magnetic alloy-C core-shell nanoparticles with tunable elemental components, showing performance variations under different Co/Ni molar ratios. These nanoparticles exhibit stability at low temperatures and slight oxidation at higher temperatures.
RESULTS IN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Jie Gao, Rui Ma, Lu Feng, Yuefeng Liu, Ralf Jackstell, Rajenahally V. Jagadeesh, Matthias Beller
Summary: This study introduces a general protocol for the selective hydrogenation and deuteration of alkenes, utilizing a specific nickel-graphitic shell-based core-shell-structured catalyst to achieve high yields of corresponding alkanes and deuterium-labeled alkanes at ambient conditions. The synthetic utility and practicability of this Ni-based hydrogenation protocol is demonstrated through gram-scale reactions and efficient catalyst recycling experiments.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Juan Esteban Montoya Cardona, Dounia Louaguef, Eric Gaffet, Nureddin Ashammakhi, Halima Alem
Summary: Despite some delays in clinical implementation, functionalized magnetic and photothermal nanostructures remain the most promising way to target hyperthermia treatment of cancer towards local tumor regions. The synthesis method and parameters play a crucial role in optimizing the physicochemical properties for efficient energy transduction into locally released heat. This review aims to provide the latest applications and prospects of nanomaterials for hyperthermia properties.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Engineering, Environmental
Lina Jia, Gaohui Du, Di Hana, Yunting Wang, Wenqi Zhao, Qingmei Su, Shukai Ding, Bingshe Xu
Summary: This study reports the synthesis of conductive polypyrrole (PPy)-wrapped Ni/NiFe2O4 nanospheres as efficient bifunctional electrocatalysts for overall water splitting. The PPy coating enhances the conductivity and ion transmission rate of the electrodes, while the interaction between PPy and Ni/NiFe2O4 improves the reaction efficiency of active sites. The magnetic electrode design prevents active site blockage and accelerates gas release, leading to superior electrocatalytic performance.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Polymer Science
Li Zhang, Hongbo Mo, Chuan Wang, Xiaofeng Li, Shuai Jiang, Weigang Fan, Yagang Zhang
Summary: Novel core-shell magnetic molecularly imprinted polymers (MMIPs) were synthesized for the adsorption of cefixime (CFX). The MMIPs showed high adsorption capacity and selective adsorption ability for CFX, and exhibited excellent reusable performance.
Article
Materials Science, Ceramics
Shujun Hu, Shibo Li, Weimin Xu, Wenbo Yu, Yang Zhou
Summary: Functional Ti3C2Tx@Ni particles with a core@shell and sandwich like structure were fabricated for electromagnetic interference (EMI) shielding applications. The EMI shielding effectiveness values increased with higher Ti3C2Tx@Ni content, achieving enhanced performance due to the synergic effect of absorption loss and magnetic loss.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
J. K. Han, A. A. Baker, J. R. I. Lee, S. K. McCall
Summary: Exchange coupling in a model core-shell system is demonstrated as a step towards 3D exchange spring magnets. High-quality core-shell nanoparticles of Ni@CoFe2O4 were fabricated using a simple two-step method. The microstructural quality was validated using TEM, confirming a well-defined interface between the core and the shell. Results showed a strongly temperature-dependent two-phase magnetic hysteresis loop, indicating a coupling of approximately 50% between the core and the shell. Element-specific XMCD hysteresis confirmed the presence of exchange coupling, suppressing the superparamagnetism of the Ni core at room temperature, and achieving a coercivity of >6 kOe at 80 K. These findings provide a pathway for the development of heterostructured metal-oxide exchange-coupled nanoparticles with improved maximum energy product.
Article
Chemistry, Physical
Jun -Wei Zhang, Xian-Wei Lv, Tie-Zhen Ren, Zheng Wang, Teresa J. Bandosz, Zhong-Yong Yuan
Summary: Heterostructure engineering of electrocatalysts allows for manipulation of nanomaterial properties and enhancement of catalytic efficiency in water electrolysis. In this study, Ni@Ni(OH)(2)/PC heterostructured nanomaterials were synthesized using a melted polymeric salt tactics, demonstrating improved electrocatalytic activity and long-term stability for water reduction and oxidation.
GREEN ENERGY & ENVIRONMENT
(2022)
Article
Nanoscience & Nanotechnology
Sei-Woong Park, Seong-Yong Jeong, Young Kook Moon, KiBeom Kim, Ji-Wook Yoon, Jong-Heun Lee
Summary: This study reports a highly selective and sensitive sensor for detecting breath isoprene, which is of great significance for monitoring the physical and physiological status of human beings as well as the early diagnosis of cardiovascular diseases.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Jimin Jeong, Min-Gu Kang, Soogil Lee, Jaimin Kang, Kyung-Jin Lee, Byong-Guk Park
Summary: In this study, the modulation of magnetic easy-cone states through voltage-controlled magnetic anisotropy (VCMA) significantly reduced the SOT switching current. The SOT switching current density is reduced by up to 50% when the easy-cone angle is changed from 0 degrees to 58 degrees. The magnetic easy-cone state is gradually modulated in a reversible and non-volatile manner, facilitating multilevel spintronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Review
Chemistry, Physical
Se Kwon Kim, Geoffrey S. D. Beach, Kyung-Jin Lee, Teruo Ono, Theo Rasing, Hyunsoo Yang
Summary: Ferrimagnets, composed of multiple antiferromagnetically coupled magnetic elements, offer advantages of both ferromagnets and antiferromagnets, including easy control of magnetization by external field, faster dynamics than ferromagnets, and potential for high-density devices. This Review provides a summary of recent progress in ferrimagnetic spintronics, focusing on functionalities such as spin transport, spin texture dynamics, and all-optical switching.
Review
Chemistry, Multidisciplinary
Young-Moo Jo, Yong Kun Jo, Jong-Heun Lee, Ho Won Jang, In-Sung Hwang, Do Joon Yoo
Summary: In order to improve the performance of gas sensors and enhance the quality of life, the use of metal-organic frameworks (MOFs) as sensing materials has been explored. MOFs are known for their high surface area, porosity, and unique surface chemistry, making them promising for gas-sensor innovations. Various types of MOFs have been developed by studying their compositional and morphological dependences, and incorporating catalysts and light activation. Additionally, MOFs have multiple applications as molecular sieves, absorptive filtering layers, and heterogeneous catalysts due to their separation properties and catalytic activity.
ADVANCED MATERIALS
(2023)
Editorial Material
Multidisciplinary Sciences
Kab-Jin Kim, Kyung-Jin Lee
Summary: Applying strain to an antiferromagnetic material allows its magnetization to be fully switched with an electric current, making it significant for next-generation magnetic memory devices.
Article
Physics, Multidisciplinary
Hyeon-Jong Park, Hye-Won Ko, Gyungchoon Go, Jung Hyun Oh, Kyoung-Whan Kim, Kyung-Jin Lee
Summary: In this study, we theoretically demonstrate the spin swapping effect in centrosymmetric ferromagnets, which is mediated by an orbital degree of freedom and does not require inversion asymmetry or impurity spin-orbit scattering. Our research emphasizes the important role of the orbital degree of freedom in describing spin-orbit-coupled transport in centrosymmetric materials.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Jong-Guk Choi, Jaehyeon Park, Min-Gu Kang, Doyoon Kim, Jae-Sung Rieh, Kyung-Jin Lee, Kab-Jin Kim, Byong-Guk Park
Summary: This study shows that the frequency of SHNOs can be controlled up to 2.1 GHz by an electric field, enabling large frequency tuning. The voltage-controlled frequency tuning of SHNOs facilitates the development of energy-efficient neuromorphic devices. Additionally, repetitive voltage pulses can be used to cumulatively control the frequency, mimicking the functions of biological synapses.
NATURE COMMUNICATIONS
(2022)
Article
Computer Science, Hardware & Architecture
Taehwan Kim, Yunho Jang, Min-Gu Kang, Byong-Guk Park, Kyung-Jin Lee, Jongsun Park
Summary: This paper proposes a spin-orbit torque magnetic random access memory (SOT-MRAM) based digital PIM architecture, utilizing SLIM cells and CRISP architecture to alleviate the burden of additional memory size and computation cycle issues, while considering a pipelining scheme to increase throughput.
IEEE TRANSACTIONS ON COMPUTERS
(2022)
Article
Nanoscience & Nanotechnology
Seon Ju Park, Young Kook Moon, Sei-Woong Park, Soo Min Lee, Tae-Hyun Kim, Soo Young Kim, Jong-Heun Lee, Young-Moo Jo
Summary: Real-time breath isoprene sensing provides non-invasive methods for monitoring human metabolism and early diagnosis of cardiovascular diseases. In this work, Co3O4@polyoxometalate yolk-shell structures were derived and showed selective isoprene detection with high chemiresistive response and low detection limit. The sensor's high performance is attributed to electronic sensitization and catalytic promotion effects, and its practical feasibility is demonstrated in smart healthcare applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Young Kook Moon, Ju Hyeong Kim, Seong-Yong Jeong, Soo Min Lee, Seon Ju Park, Tae Hyun Kim, Jong-Heun Lee, Yun Chan Kang
Summary: This study presents a novel bilayer ethylene gas sensor consisting of a Pd-doped V2O5-TiO2 yolk-shell catalytic overlayer and an In2O3 sensing layer. The sensor exhibits high sensitivity and selectivity towards ethylene by reforming it into more reactive acetaldehyde and filtering interference gases into non-reactive forms. This unique bilayer sensor has great potential for monitoring fruit ripeness.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Sang Hun Kim, Young Kook Moon, Jong-Heun Lee, Yun Chan Kang, Seong-Yong Jeong
Summary: A chemiresistive-type gas sensor for detecting exhaled hydrogen has been developed, showing excellent selectivity, high response speed, and low detection limit. The sensor holds great potential for disease diagnosis.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Kyuhwe Kang, Hiroki Omura, Daniel Yesudas, OukJae Lee, Kyung-Jin Lee, Hyun-Woo Lee, Tomoyasu Taniyama, Gyung-Min Choi
Summary: In this study, the spin current in a FeRh/Cu heterostructure during the ultrafast magnetization process is directly measured, revealing a significant correlation between the spin current and the magnetization dynamics. This suggests an angular momentum transfer mechanism from electrons to magnons, involving spatial transport and dissipation of angular momentum. This finding contributes to a better understanding of laser-induced ultrafast magnetization processes.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Eun-Sang Park, Dong-Kyu Lee, Fei Xue, Byoung-Chul Min, Hyun Cheol Koo, Paul M. Haney, Kyoung-Whan Kim, Kyung-Jin Lee
Summary: The symmetry of normal metal/ferromagnet bilayers allows spin-orbit torques (SOTs) to have two distinct angular dependences on the magnetization direction. The most studied forms of SOT are the lowest-order SOT, which consist of fieldlike and dampinglike torques. There are also higher-order SOT forms that have different spin polarization and an additional factor of magnetization direction dependence. This study measures both the lowest-order and higher-order angular dependences of SOTs in three types of bilayers and finds that the higher-order SOT is dominant for one type of bilayer while negligible for the others. Macrospin simulations show that higher-order SOT can significantly affect magnetization dynamics, which aligns with SOT-induced switching experiments.
Article
Materials Science, Multidisciplinary
Jaechul Shim, Kyung-Jin Lee
Summary: Highly entangled states are crucial for quantum information processing. In this study, we theoretically investigate magnon-magnon entanglement in a compensated ferrimagnet and find that the steady-state magnon-magnon entanglement is significantly enhanced near the angular momentum compensation point when magnons are coupled with photons in a cavity. This enhancement is attributed to the ability of the ground state of the ferrimagnet to approach the Einstein-Podolsky-Rosen state. This unique feature of ferrimagnets with different Lande g factors between sublattices results in higher magnon entanglement compared to ferromagnets and antiferromagnets.
Review
Chemistry, Multidisciplinary
Young Kook Moon, Ki Beom Kim, Seong-Yong Jeong, Jong-Heun Lee
Summary: This article discusses the strategies for designing highly selective and sensitive volatile aromatic compound gas sensors using oxide chemiresistors. Key approaches include thermal activation, design of sensing materials with high catalytic activity, utilization of catalytic microreactors and bilayer structures with catalytic overlayer, and pretreatment of analyte gases or post analysis of sensing signals. Future perspectives in terms of designing sensing materials and sensor structures for high-performance and robust volatile aromatic compounds gas sensors are also provided.
CHEMICAL COMMUNICATIONS
(2022)