Article
Chemistry, Multidisciplinary
Andrea Atrei, Fariba Fahmideh Mahdizadeh, Maria Camilla Baratto, Andrea Scala
Summary: The size, size distribution, and magnetic properties of magnetite nanoparticles prepared under different citrate conditions were investigated by XRD, DLS, EPR, and magnetization measurements. Citrate was found to affect the size and magnetic properties of the nanoparticles, with citrate-coated nanoparticles showing greater stability.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Analytical
Monika Sobiech, Karol Synoradzki, Tamara J. Bednarchuk, Kamil Sobczak, Marta Janczura, Joanna Giebultowicz, Piotr Lulinski
Summary: This study reveals the complex nature of nanocrystalline magnetic cores and verifies the effectiveness of magnetic molecularly imprinted polymer (MMIP) as a sorbent for biomolecule analysis. The adsorbate-sorbent process is independent of the amount of siloxane functionalized magnetite core (Fe3O4@SiO2-MPS).
MICROCHEMICAL JOURNAL
(2022)
Article
Polymer Science
Benjamin Constant-Mandiola, Hector Aguilar-Bolados, Julian Geshev, Raul Quijada
Summary: A study has been reported regarding the development of new recyclable and/or biodegradable magnetic polymeric materials by adding magnetite supported on thermally reduced graphene oxide to polymeric matrices. The nanomaterials obtained at different ratios and temperatures showed varying coercivity, which can be used to prepare polylactic acid and polypropylene nanocomposites with different coercivity values. Theoretical models were used to analyze the mechanical and magnetic properties, providing a basis for further research.
Article
Chemistry, Multidisciplinary
Luran Zhang, Xinchen Du, Hongjie Lu, Dandan Gao, Huan Liu, Qilong Lin, Yongze Cao, Jiyang Xie, Wanbiao Hu
Summary: FePt and FePtCu nanoparticles with good dispersion were successfully fabricated using a simple, green, one-step solid-phase reduction method, with the addition of 5% Cu significantly improving the properties of FePt nanoparticles. The highest performance FePtCu nanoparticles were obtained when annealed at 750 degrees Celsius.
Article
Chemistry, Multidisciplinary
Adam Szatmari, Rares Bortnic, Gabriela Souca, Razvan Hirian, Lucian Barbu-Tudoran, Fran Nekvapil, Cristian Iacovita, Emil Burzo, Roxana Dudric, Romulus Tetean
Summary: Co1-xZnxFe2O4 nanoparticles (0 <= x <= 1) were synthesized via a green sol-gel combustion method, and their characteristics were studied using various techniques. The nanoparticles showed high crystallinity and exhibited a cubic Fd-3m structure. The presence of cobalt, zinc, iron, and oxygen in the samples was confirmed through EDS analysis. Raman spectra revealed the preferential location of Zn ions in T sites for low Zn concentrations. The magnetic properties of the nanoparticles were discussed based on the Raman results, showing an increase in magnetization with increasing Zn content for x < 0.5. Co ferrite doped with 30% Zn exhibited the highest SAR values, which increased linearly with H from 20 to 60 kA/m.
Article
Chemistry, Analytical
Cristina B. Adamo, Ronei J. Poppi, Dosil P. de Jesus
Summary: This work shows that depositing a Ni-P film on a PDMS substrate can enhance the magnetic aggregation of gold-modified magnetic nanoparticles, improving their performance in surface-enhanced Raman scattering detection. By combining the PDMS-Ni-P substrate with a permanent NdFeB magnet, the aggregation of Fe3O4/AuNPs is improved, leading to significantly higher SERS signals for crystal violet, adenine, and thiabendazole.
MICROCHEMICAL JOURNAL
(2021)
Article
Chemistry, Physical
Pedro A. Calderon Bedoya, Pablo M. Botta, Paula G. Bercoff, Maria A. Fanovich
Summary: Iron oxide nanoparticles were successfully prepared via mechanochemical synthesis from three different reactive systems. The study investigated the effects of various iron salts and metallic iron on the properties of the nanoparticles, and determined high magnetization of the obtained iron oxide nanoparticles across a range of temperatures. The presence of metallic iron was found to be crucial in the formation of magnetic phases in the nanoparticles.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Viktoriia Zheltova, Kirill Korolev-Zeleniy, Anton Mazur, Valentin Semenov, Natalia Bobrysheva, Mikhail Osmolowsky, Mikhail Voznesenskiy, Olga Osmolovskaya
Summary: This study focuses on the magnetic properties of Fe3O4 core-shell nanoparticles with a ZnO protective shell and the formation and characteristics of the transition layer between the core and the shell. The results show the successful synthesis of a ZnO shell and the presence of a transition layer, which composition depends on the synthesis method. Correlations between magnetic and thermal characteristics and the transition layer composition were found.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Condensed Matter
Krishna Priya Hazarika, Rushikesh Fopase, Lalit M. Pandey, J. P. Borah
Summary: This research aims to enhance the heating efficiency of Fe3O4 nanoparticles by doping Gd in the matrix, making it a potential candidate for magnetic hyperthermia applications.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Chemistry, Multidisciplinary
Johannes Dietrich, Alexius Enke, Nils Wilharm, Robert Konieczny, Andriy Lotnyk, Andre Anders, Stefan G. G. Mayr
Summary: Iron oxide nanoparticles with a mean size of approximately 5 nm were synthesized using energetic electrons to irradiate micro-emulsions containing iron salts. The properties of the nanoparticles were investigated using various techniques, revealing that the formation of superparamagnetic nanoparticles starts at a dose of 50 kGy. The particles tend to form clusters and show increasing crystallinity and yield with increasing doses.
Article
Materials Science, Multidisciplinary
Urszula Klekotka, Sylwia Boratyynsa, Dariusz Satu, Beata Kalska-Szostko
Summary: In this study, long-term thermal treatment of different types of magnetite nanoparticles was conducted to investigate their transformation to other iron oxides. The results showed that nanoparticles synthesized by coprecipitation of iron chlorides have lower thermal stability compared to those obtained by thermal decomposition. However, neither type of nanoparticles oxidized to hematite even when exposed to gentle heating (below 50 degrees C) for an extended period of time.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Stanislav Campelj, Matic Pobreznik, Tomas Landovsky, Janez Kovac, Layla Martin-Samos, Vera Hamplova, Darja Lisjak
Summary: In this study, MNPs were successfully functionalized with CAT, GAL, CAF, and NDA at different pH values. The functionalized MNPs showed higher saturation magnetizations (M-s) compared to the starting material. XPS analyses confirmed the presence of Fe(III) ions on the surface, ruling out the formation of magnetite. DFT calculations demonstrated that the adsorption of catechols did not affect the M-s. The increase in the average size of the MNPs and the decrease in the fraction of the smallest MNPs explained the observed increase in M-s values.
Article
Chemistry, Multidisciplinary
Joana Goncalves, Claudia Nunes, Liliana Ferreira, Maria Margarida Cruz, Helena Oliveira, Veronica Bastos, Alvaro Mayoral, Qing Zhang, Paula Ferreira
Summary: Fucoidan-coated magnetite nanoparticles exhibit great potential for magnetic hyperthermia therapy, showing high specific loss power and intrinsic loss power values while maintaining biocompatibility, meeting the required criteria for MHT application.
Article
Materials Science, Ceramics
Yong Hou, Guo-Hua Zhang, Kuo-Chih Chou
Summary: The study found that the atmosphere during melting and heat treatment, heat treatment temperature, Fe3O4 content, and basicity all had influences on the magnetic properties of magnetite-based glass ceramics. The saturation magnetisation and coercivity were affected by factors such as melting atmosphere, sintering temperature, Fe3O4 content, and basicity.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
L. E. De Leon Prado, D. A. Cortes Hernandez, J. C. Escobedo Bocardo, G. F. Hurtado Lopez
Summary: In this study, magnetic nanoparticles with mixed ferrites were synthesized via the sol-gel method and their physicochemical properties were evaluated under different heat treatment conditions. The obtained nanosized magnetic ferrites showed a single crystalline phase, close to the superparamagnetic regime, and exhibited heating ability under the application of a magnetic field.
CERAMICS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Oussama Boutahir, Souhail Lakhlifi, Sidi Abdelmajid Ait Abdelkader, Mourad Boutahir, Abdelhai Rahmani, Hassane Chadli, Jose Mejia-Lopez, Abdelali Rahmani
Summary: In this paper, a force constant model developed for Black phosphorene was presented to replicate the vibrational properties calculated from density functional theory. The results showed excellent agreement with experimental data from Raman spectroscopy measurements. By studying the impact of edges and widths on the vibrational properties of phosphorene nanoribbons, additional Raman modes related to ribbon width were observed and an equation for estimating ribbon width was proposed.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Chemistry, Physical
D. Mejia-Burgos, S. A. Berrios, J. Mazo-Zuluaga, J. Mejia-Lopez
Summary: In this study, an extensive molecular dynamics investigation was conducted on the thermomechanical properties of cylindrical Fe, Ni, and Fe/Ni core/shell nanowires under uniaxial tensile strain. The nanowires were found to be elastically softer than bulk iron, with a weakening effect observed as sample diameter increased. Additionally, shape memory effect was observed in Fe/Ni core/shell systems grown along specific crystal directions, making them potentially attractive for technical applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Condensed Matter
Oscar A. Restrepo, Oscar Arnache, Johans Restrepo, Charlotte S. Becquart, Normand Mousseau
Summary: Using Buckingham potentials, the mechanical properties of zinc spinel ferrites were studied and the effects of pressure and randomness of Ze and Fe on their properties were analyzed. It was found that pressure affects the deformations and brittleness of the materials, and partial inverse spinels exhibit better ductility. The randomness of Ze and Fe plays an important role in the formation and stability of vacancies in the inverse spinel.
SOLID STATE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Mauricio Galvis, Fredy Mesa, Johans Restrepo
Summary: This work investigates the zero temperature hysteretic properties of iron quadrangular nanoprisms and the size conditions for the formation of magnetic vortex states. A field-driven magnetic phase diagram is proposed based on different aspect ratios and free boundary conditions, where vortex states are found to be stable along the hysteresis loops. Micromagnetic simulations and topological charge calculations are used to validate the results.
Article
Physics, Multidisciplinary
Esteban Marulanda, Alejandro Restrepo, Johans Restrepo
Summary: In classical physics, the energy per degree of freedom is the same, but in quantum mechanics, the energy is not equally distributed due to non-commutativity of observables and possible non-Markovian dynamics. We propose a correspondence between the classical energy equipartition theorem and its counterpart in quantum mechanics based on the Wigner representation. Additionally, we demonstrate that the classical result is recovered in the high-temperature regime.
Article
Chemistry, Physical
Felipe Matamala-Troncoso, Cesar Saez-Navarrete, Jose Mejia-Lopez, Griselda Garcia, Jose Rebolledo-Oyarce, Cuong Ky Nguyen, Douglas R. MacFarlane, Mauricio Isaacs
Summary: The formation mechanism of Cu2O/TiO2 heterojunction was studied by electrochemically depositing Cu2O molecules on TiO2 nanoparticles. The experimental results, combined with theoretical calculations, revealed the initial steps of Cu2O molecule formation on TiO2 nanoparticles. It was found that the formation of a Cu2O nanowire-like network on the TiO2 nanoparticle matrix promotes charge transfer at the electrolyte/semiconductor interface, enhancing the electrode behavior.
SURFACES AND INTERFACES
(2023)
Article
Multidisciplinary Sciences
Ever A. Velasquez, Johann Mazo-Zuluaga, Jose Mejia-Lopez
Summary: This study discusses the magnetoresistance and magnetic properties of Ni-Fe bi-segmented cylindrical nanodots with different diameters and heights. The structural and magnetic relaxation effects are investigated using the density functional theory approach, and the magnetoresistance and magnetic behaviors are explored through atomistic simulations using the Fast Monte Carlo methodology. The convoluted magnetization reversal schemes are discussed based on the magnetic hysteresis and magnetoresistance signals, which are influenced by the size and shape effects induced by dipolar interactions and the interplay among exchange interactions.
ADVANCED THEORY AND SIMULATIONS
(2023)
Article
Multidisciplinary Sciences
Jose Mejia-Lopez, Sinhue Lopez-Moreno, Johann Mazo-Zuluaga, Pricila Betbirai Romero-Vazquez, Jose Luis Moran-Lopez
Summary: An extensive study on isolated FeX2 (X = F, Cl, Br, I) nanowires using first-principles and atomistic Monte Carlo simulations is presented. The results show that these nanowires crystallize in anti-ferromagnetic arrangement and belong to the space group P42/mmc, making them potentially promising materials for applications such as lithium-ion batteries.
ADVANCED THEORY AND SIMULATIONS
(2023)
Article
Mathematics, Interdisciplinary Applications
Jose Antonio Valencia, Johans Restrepo, Hernan David Salinas, Elisabeth Restrepo
Summary: A methodology is developed to deform the surface of a magnetorheological elastomer (MRE) under the influence of an external magnetic field. The surface morphology of MREs is randomly generated using the Garcia and Stoll method. Deformations are induced by the translations of magnetic particles inside the elastomer, resulting in changes in surface roughness.
Article
Nanoscience & Nanotechnology
J. C. Zapata, J. Restrepo
Summary: Simulations were performed on a system of magnetite single-domain magnetic nanoparticles in an aqueous colloidal suspension at various temperatures. The study focused on analyzing the magnetization response of the system to a time-dependent magnetic field at specific frequencies. The results showed that Brownian relaxation played a role in aligning the anisotropy axes with the external field, thereby enhancing the magnetic anisotropy and improving the remanence and squareness of the hysteresis loops.
Article
Physics, Applied
Mauricio Galvis-Patino, Johans Restrepo-Cardenas
Summary: This study investigates the micromagnetic properties and magnetization dynamics of a system of Fe cuboids. It reveals that the coercive field decreases with increasing azimuthal angle and that magnetization diagrams indicate the presence of magnetic domains and walls in the plane. The energy graphs show the competition between different energy contributions along the hysteresis loops.
MOMENTO-REVISTA DE FISICA
(2022)
Article
Chemistry, Physical
J. Mejia-Lopez, E. A. Velasquez, J. Mazo-Zuluaga
Summary: Based on many-body potentials, inertia tensors, and Density Functional Theory, a method is proposed to obtain the lowest energy states of any cluster system. The Pt6Cu6 cluster case is studied, revealing various isomers with significantly lower energy than the previously believed ground state. The oscillating behavior of global chemical descriptors, such as ionization potential, electron affinity, and chemical hardness, suggests higher deactivation rate by sintering processes and stronger adsorption of small molecules on higher energy isomers. The electronic, magnetic, anisotropy, vibrational, and thermal properties of these clusters are discussed, providing valuable information for future experiments and applications in catalysis, spintronics, molecular magnetism, and magnetic storage information.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Juan Camilo Zapata, Johans Restrepo
Summary: A canonical Markov Chain Monte Carlo method was used to study the hysteretic properties of a collection of magnetic nanoparticles with uniaxial magneto-crystalline anisotropy. The impact of acceptance rate on the magnetic properties was explored by analyzing magnetization behavior, revealing differences in blocked and superparamagnetic states for high and low acceptance rates. Additionally, the interplay between acceptance rate, temperature, hysteresis curves, and saturation processes was also discussed.
