Article
Materials Science, Multidisciplinary
Xiaokang Li, Shan Jiang, Qingkai Meng, Huakun Zuo, Zengwei Zhu, Leon Balents, Kamran Behnia
Summary: The magnetic free energy in Mn3Sn, a noncollinear antiferromagnet, has superquadratic components, which drive the magnetocrystalline anisotropy energy (MAE). Experimental and theoretical analyses demonstrate the contributions of odd terms in the magnetic field and the resulting angular oscillations in torque response. The deformation of the spin texture induced by the magnetic field is found to be the driving force behind the MAE in Mn3Sn.
Article
Engineering, Electrical & Electronic
Ranjan Roy, Dushyant Singh, M. Senthil Kumar
Summary: The influence of Si spacer layer on the structural and magnetic properties of Co/Si multilayers was studied, as well as the role of disordered surface spins at the interface of the multilayers. A series of samples [Co(50 angstrom)/Si(t(Si) angstrom)](20) prepared by DC magnetron sputtering were characterized, and structural and microstructural studies indicated that the crystallite size increased with decrease in the Si layer thickness. The magnetization increased and tended to the bulk value of Co while the thickness of the Si layers decreased. The effect of interfacial disordered spins changed the shape of the hysteresis loop observed in the low field regime, leading to the rise of a crossed magnetic hysteresis loop of the multilayers.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Chemistry, Physical
Yu. V. Knyazev, O. P. Ikkert, S. V. Semenov, M. N. Volochaev, M. S. Molokeev, M. S. Platunov, E. V. Khramov, A. A. Dubrovskiy, N. P. Shestakov, E. D. Smorodina, O. V. Karnachuk, D. A. Balaev
Summary: A composite material based on nanorod-shaped greigite crystallites with adsorbed ferrihydrite nanoparticles has been synthesized through biomineralization, and its phase composition and magnetic properties have been investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Debabrata Das, Yohannes Getahun, Francelia Sanchez Escobar, Rebecca Romero, Ahmed A. El-Gendy, C. V. Ramana
Summary: The evolution of superparamagnetic behavior of Nb-Cr-Ta-V-W refractory high entropy alloy (RHEA) nanoparticles synthesized by mechanical pulverization technique was investigated. The results showed that the size of the nanoparticles decreased with milling time, while retaining the parent crystal structure and phase. The RHEA nanoparticles exhibited a temperature independent superparamagnetic nature.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Applied
David Slay, Dongmei Cao, Eric C. Ferre, Michalis Charilaou
Summary: This study reveals that dipole-dipole interactions have a strong effect on the collective magnetic state, despite thermal fluctuations, and should be considered in high-frequency applications. The configuration of iron-oxide nanoparticles has a significant impact on their effective magnetic anisotropy at short time scales, an order of magnitude larger than the intrinsic magnetocrystalline anisotropy.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Tim Granath, Karl Mandel, Peer Loebmann
Summary: This study demonstrates the importance of considering modification parameters and their effects on adsorption types in the modification of nanoparticles. By examining the effect of pH on superparamagnetic iron oxide nanoparticles modified with citrate, the study reveals the pH-dependent linking of citrate carboxyl groups to the particle surface and their interaction with ammonia used for pH adjustment. These findings help explain the observed differences in properties when the citrate-modified nanoparticles are coated with silica or redispersed after spray-drying.
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
(2022)
Article
Physics, Applied
J. M. Orozco-Henao, D. Muraca, F. H. Sanchez, P. Mendoza Zelis
Summary: The stoichiometry and effective anisotropy constant (K-eff) of iron-oxide nanoparticles with different sizes were studied using Mossbauer spectroscopy. The K-eff value was determined by comparing the size distribution and KeffV product obtained from Mossbauer spectra fitting. An overall surface anisotropy constant Ks was obtained by analyzing the relationship between the mean NP size, experimentally determined K-eff and mean magnetic anisotropy. The study also observed a relation between KeffV values and the magnetite/maghemite fraction in each sample.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Lorenzo Cursi, Silvia Vercellino, Mura M. McCafferty, Emily Sheridan, Vanya Petseva, Laurent Adumeau, Kenneth A. Dawson
Summary: Magnetic nanoparticles are valuable tools for studying complex intracellular bio-nano interactions. By synthesizing biocompatible multifunctional nanoparticles with fluorescent properties, intracellular tracking of nanoparticles can be achieved, providing a promising approach for studying bio-nano interactions.
Article
Environmental Sciences
Zunjian Bian, Shengbiao Wu, Jean-Louis Roujean, Biao Cao, Hua Li, Gaofei Yin, Yongming Du, Qing Xiao, Qinhuo Liu
Summary: Land surface temperature (LST) is an essential climate variable (ECV) used to estimate energy budget and measure climate change effects. Forests are impacted by temperature rise, and accurate monitoring is necessary, taking into account the directional anisotropy (DA) of forests. A visible and near-infrared (VNIR) radiative transfer model called FRT is used to characterize the DA of forest temperature, considering vertical thermal gradients and multiple scattering processes.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Biochemistry & Molecular Biology
A. F. P. Allwin Mabes Raj, Maja Bauman, Nena Dimitrusev, Lamiaa M. A. Ali, Melanie Onofre, Magali Gary-Bobo, Jean-Olivier Durand, Aleksandra Lobnik, Aljosa Kosak
Summary: Superparamagnetic adsorbents based on APTMS-coated maghemite (& gamma;Fe2O3@SiO2-NH2) and cobalt ferrite (CoFe2O4@SiO2-NH2) nanoparticles were prepared and characterized. The adsorption of Dy3+, Tb3+, and Hg2+ ions onto the adsorbents was tested and evaluated. Both adsorbents showed high adsorption efficiency and capacity. They also demonstrated reusability and no cytotoxicity in zebrafish embryos.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Multidisciplinary Sciences
Anku Guha, Mihir Sahoo, Khorsed Alam, D. Krishna Rao, Prasenjit Sen, Tharangattu N. Narayanan
Summary: In this study, the structural changes in water coordination in high alkaline electrolytes were investigated using experimental and density functional theory methods. The results showed that these structural changes could be a possible reason for the reduced catalytic activity of platinum electrodes in high pH environments.
Article
Energy & Fuels
Hongfang Ma, Yi Yang, Haoyue Fu, Haitao Zhang, Weixin Qian, Qiwen Sun, Weiyong Ying
Summary: This study explored the synthesis of light olefins through high-temperature Fischer-Tropsch synthesis using alkaline-earth metals modified FeMn catalysts. It was found that the interaction of Ca, Sr, and Ba improved CO dissociative adsorption and reduced H species adsorption, enhancing CO conversion and C-2(=)-C-4(=) selectivity. The FeMnSrNa catalyst exhibited the best FTS performance due to its highest surface basicity, strongest CO dissociative adsorption, and highest active iron carbide content.
Article
Chemistry, Physical
Esther Barrena, Rogger Palacios-Rivera, Jose I. Martinez, Carmen Ocal
Summary: The orientation of molecular dipoles in chloroaluminum phthalocyanine (ClAlPc) layers affects the adsorption and diffusion behavior of C-60 on Au(111). The balance between attractive and repulsive interactions plays a crucial role in the ordered supramolecular aggregation of fullerenes. Density functional theory calculations support the experimental observations, emphasizing the importance of charge transfer and surface corrugation in the formation of co-adsorbed C-60 and ClAlPc layers.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Gang Gui, Ziqi Fan, Yihuan Ning, Cancan Yuan, Baolin Zhang, Qin Xu
Summary: By loading paclitaxel onto FA-targeted SPIONs, the study succeeded in enhancing the drug's water solubility, demonstrating good stability and targeting ability, with potential anti-tumor activity.
INTERNATIONAL JOURNAL OF NANOMEDICINE
(2021)
Article
Materials Science, Biomaterials
Yaser Rehman, Zhenxiang Cheng, Xiaolin Wang, Xu-Feng Huang, Konstantin Konstantinov
Summary: In this study, size- and shape-controlled two-dimensional superparamagnetic maghemite quantum flakes (MQFs) were synthesized via a simple hydrothermal method for biological applications. These MQFs exhibited superparamagnetic behavior with high saturation magnetization and low coercivity, and showed selective toxicity towards different cell lines based on ROS scavenging/generation and cellular uptake mechanisms. Furthermore, the MQFs demonstrated potential for cancer therapy through ROS generation by hyperthermia in a selective microenvironment, highlighting their theranostic capabilities.
JOURNAL OF MATERIALS CHEMISTRY B
(2021)
Article
Engineering, Environmental
Rubaya Yeasmin, Seung-Ik Han, Le Thai Duy, Byungmin Ahn, Hyungtak Seo
Summary: This article introduces the development of a multifunctional self-healing, stretchable, deformable, biocompatible, transparent, and self-adhesive composite based on networking PBS (polyborosiloxane) and Ecoflex. The composite possesses fast self-healing capability, high stretchability, transparency, ideal electrical insulation, and good chemical stability. It also exhibits consistent thermal stability at high temperatures. These remarkable properties make it an essential skin-mimicking substrate for biomedical and wearable applications such as e-skin.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Cheenepalli Nagarjuna, Sheetal Kumar Dewangan, Ashutosh Sharma, Kwan Lee, Soon-Jik Hong, Byungmin Ahn
Summary: An equiatomic CoCrFeMnNi high entropy alloy (HEA) was prepared by gas atomization process. High-energy milling was conducted to investigate the effects of milling parameters on the morphology and crystallographic properties of HEA powders. X-ray diffraction and scanning electron microscopy were used for phase identification and morphology observation of the milled powders. Both atomized and milled powders exhibited a single-phase face-centered cubic solid solution. The crystallite size (CS) decreased from 39.7 to 6.56 nm and the lattice strain (LS) increased from 0.25%-1.48% with increasing milling time from 0 to 240 min. Furthermore, an artificial neural network (ANN) approach provided accurate predictions of CS and LS with accuracies of 96.25% and 93.43%, respectively.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Cheenepalli Nagarjuna, Ashutosh Sharma, Kwan Lee, Soon-Jik Hong, Byungmin Ahn
Summary: This study focuses on enhancing the strength and wear resistance of face-centered cubic (FCC)-structured CoCrFeMnNi high entropy alloy (HEA) by incorporating HfO2 nanoparticles (NPs) through a powder metallurgy approach. The results reveal that the addition of HfO2 increases the hardness and compressive yield strength of the alloy, while reducing the coefficient of friction and wear rates. This study demonstrates the feasibility of producing high-performance oxide dispersion-strengthened HEAs for advanced structural applications.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Environmental Studies
Nahyeon Lee, Byungmin Ahn, Jechan Lee
Summary: This study developed a solvent-based method to recover acrylate polymer from display film waste. 2-butanol and methyl acetate were chosen as the organic solvents for the recovery process. The effects of different recovery parameters on the polymer recovery were explored, and 2-butanol was found to be the most effective solvent with a recovery yield of 8.28%.
ENERGY & ENVIRONMENT
(2023)
Article
Chemistry, Physical
Hansung Lee, Ashutosh Sharma, Byungmin Ahn
Summary: This study investigates the influence of Si addition on the microstructure, compressive strength, and fracture mechanisms of FeCoNiAlSi high-entropy alloys (HEAs). The results show that the addition of Si changes the phase structure of the alloy and increases its Vickers hardness and compressive strength. The findings suggest that HEAs with different Si contents can be used for designing high-strength structural alloys for automotive applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Metallurgy & Metallurgical Engineering
Sheetal Kumar Dewangan, Cheenepalli Nagarjuna, Hansung Lee, Ashutosh Sharma, Byungmin Ahn
Summary: A preliminary study was conducted to investigate the impact of pressureless sintering on the surface morphology of AlFeCoNi alloy with the addition of Si element. The study aimed to determine the feasibility of achieving densification of high entropy alloys using conventional sintering techniques. The results showed that even with the addition of Si, the high entropy alloys maintained a single-phase BCC structure. Thermodynamic simulation (CALPHAD) was used to predict phase formation, and the effects of sintering temperatures on crystallite sizes and lattice strains were discussed. Densification mechanisms occurring at different sintering temperatures were also analyzed. While porosity was observed, the density of high entropy alloys improved with higher sintering temperatures.
Article
Metallurgy & Metallurgical Engineering
Hansung Lee, Ashutosh Sharma, Minsu Kim, Byungmin Ahn
Summary: This study investigated the effects of Cu addition on AlFeMnTiSi0.75Cux (x = 0, 0.25, 0.5, 0.75, 1.00) high entropy alloys (HEAs) prepared via mechanical alloying and spark plasma sintering. The analysis of the HEA powders revealed a multiphase structure. After sintering at 900°C, the formation of BCC, μ, and L2(1) phases in the densified HEAs was enhanced. The improved microstructural and mechanical properties were observed at the optimal Cu fraction (0.25 molar ratio).
Article
Metallurgy & Metallurgical Engineering
Cheenepalli Nagarjuna, Sheetal Kumar Dewangan, Kwan Lee, Byungmin Ahn
Summary: TiC-reinforced CoCrFeMnNi high-entropy alloy composites were prepared using mechanical alloying and spark plasma sintering. The study focused on the phase composition, microstructure, mechanical properties, and thermal expansion behavior of the composites. The addition of TiC did not affect the crystal structure, but had a significant influence on the microstructure and mechanical properties. Increasing TiC content resulted in decreased grain size, leading to enhanced hardness and compressive yield strength due to grain boundary and dispersion strengthening effects. The thermal expansion curves showed linear increments up to 800 degrees C and decreased with increasing TiC content.
Article
Chemistry, Physical
Sheetal Kumar Dewangan, Ashutosh Sharma, Hansung Lee, Vinod Kumar, Byungmin Ahn
Summary: This paper describes the synthesis of tungsten-containing high-entropy alloys (HEAs) using a powder metallurgy process and spark plasma sintering (SPS) to compact the powder. XRD and SEM analyses showed the main phases formed were body-centered and face-centered cubic phases, with a sigma phase observed after sintering at 900 celcius. The introduction of tungsten in HEAs resulted in high hardness and elastic modulus, and the experimental creep displacement data were accurately predicted by an artificial neural network (ANN) model.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Cheenepalli Nagarjuna, Sheetal Kumar Dewangan, Hansung Lee, Byungmin Ahn
Summary: A novel equiatomic CrFeNiTiV high entropy alloy (HEA) was synthesized through mechanical alloying and spark plasma sintering, and the effects of heat treatment temperature on the phase stability and mechanical properties were investigated. The results showed that the phase and mechanical properties of the HEA were improved after heat treatment, making it suitable for high-temperature applications.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
K. Raja Rao, Sheetal Kumar Dewangan, A. H. Seikh, Sudip Kumar Sinha, Byungmin Ahn
Summary: This study investigates the preparation of a high-entropy alloy through mechanical alloying and vacuum hot pressing, and examines the effect of different consolidation temperatures on the microstructure and hardness of the alloy.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Hansung Lee, Minsu Kim, Ashutosh Sharma, Byungmin Ahn
Summary: This study investigated the dry sliding wear behavior of AlSi0.75TiMnFeCux (x = 0, 0.25, 0.5) high-entropy alloys (HEAs) prepared through mechanical alloying (MA) and spark plasma sintering (SPS). The microstructure and phase evolution were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The wear resistance of the HEAs was evaluated under dry air atmosphere using a reciprocating wear monitor. The results showed that the addition of Cu up to 0.25 molar ratio improved the microhardness and wear behavior of AlSi0.75TiMnFeCux HEAs, but beyond that, a mixed adhesive-abrasive wear mechanism dominated.
Article
Engineering, Mechanical
Hansung Lee, Ashutosh Sharma, Byungmin Ahn
Summary: The wear behavior of FeCoNiAlSi0.2 high-entropy alloy and Si-free FeCoNiAl in reciprocating sliding wear process for automotive piston rings was evaluated. Advanced powder metallurgy was used to prepare the high-entropy alloys to overcome the issues of shrinkage porosity, segregation defects, poor densification, and wear resistance. The morphology, hardness, wear, and friction properties were investigated.
Article
Materials Science, Multidisciplinary
Sheetal Kumar Dewangan, Ornov Maulik, Devesh Kumar, Saurav Kumar, Vinod Kumar, Byungmin Ahn
Summary: In this study, the impact of heat treatments on AlFeCuCrMgx alloys prepared by mechanical alloying and spark plasma sintering was investigated. The phase evolution and microstructure changes of these alloys at different temperatures were studied using XRD, SEM, and TEM techniques.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Neeraj Kumar, Ashutosh Sharma, M. K. Manoj, Byungmin Ahn
Summary: This study prepared self-lubricating aluminum matrix composites using powder metallurgy technique and evaluated their wear, coefficient of friction, and corrosion resistance under different conditions. The results demonstrated that the addition of MoS2 reduced wear and coefficient of friction while improving corrosion resistance. The effects of load and reinforcement concentration were more significant.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)