Article
Chemistry, Multidisciplinary
Evgeny A. Gorbachev, Ekaterina S. Kozlyakova, Liudmila N. Alyabyeva, Asmaa Ahmed, Lev A. Trusov
Summary: The temperature behavior of the magnetic properties and natural ferromagnetic resonance has been studied for single-domain Sr1-x/12Cax/12Fe12-xAlxO19 (x = 1.5-5.5) particles. It is found that the samples exhibit giant room temperature coercivities (20-36 kOe) and sub-terahertz NFMR frequencies (160-250 GHz) due to high aluminum substitution in M-type hexaferrites. Moreover, the coercivity and NFMR frequencies show a maximum shifting to the low-temperature region with an increase in aluminum concentration, with the highest values observed for x = 5.5 at 180 K.
MATERIALS HORIZONS
(2023)
Article
Engineering, Electrical & Electronic
D. Ravinder, D. Ravinder Nayak, Sridhar Rapolu, Khalid Mujasam Batoo, Emad H. Raslan, Mohammad Hadi
Summary: In this study, a series of mixed Li-Fe-Cr oxide nano-ferrite systems were successfully synthesized using the citrate gel auto-combustion method. Structural parameters and surface morphology were characterized, showing that Cr3+ substitution significantly influenced the magnetic properties. The magnetic behavior of two samples exhibited super-paramagnetic behavior at high temperatures.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Physics, Applied
Michele Petrecca, Beatrice Muzzi, Stefano Maria Oliveri, Martin Albino, Nader Yaacoub, Davide Peddis, Cesar de Julian Fernandez, Claudia Innocenti, Claudio Sangregorio
Summary: The article discusses the exploitation of exchange coupling between hard and soft magnetic materials to enhance the magnetic performance of rare-earth free permanent magnets. It reports the synthesis of nanometric SFO and zinc-doped ferrite composites through scalable and eco-friendly approaches. Despite promising results in forming exchange coupled composite at 1100 degrees C, there was no improvement in energy product, indicating a need for further experimental efforts.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Applied
Nuchjaree Salidkul, Wiyada Mongkolthanaruk, Kajornsak Faungnawakij, Supree Pinitsoontorn
Summary: A method to fabricate hard magnetic membranes based on bacterial cellulose (BC) matrix and magnetically hard phase barium ferrite (BFO) nanoparticles was proposed. The nanocomposites exhibited improved tensile strength and modulus at low BFO concentration, increased magnetization with BFO content, high flexibility upon bending, and sensitivity to external magnetic fields. Unlike other magnetic BC membranes, BC/BFO nanocomposites demonstrated hard magnetic properties, retaining their magnetic attraction after being magnetized by a permanent magnet, opening up possibilities for applications in various fields.
CARBOHYDRATE POLYMERS
(2021)
Article
Materials Science, Multidisciplinary
W. M. Gamal, Asmaa A. H. El-Bassuony, R. S. Hafez, H. K. Abdelsalam
Summary: A novel nanocomposite consisting of CoLa/LaH and LaH nanoparticles was synthesized and showed improved magnetic measurements. The nanocomposite displayed a higher operating frequency and could be potentially used in magnetic targeting and separators.
Article
Chemistry, Multidisciplinary
M. Aminul Islam, M. Razibul Hasan, M. Mahbubabl Haque, Rimi Rashid, Ishtiaque M. Syed, S. Manjura Hoque
Summary: Surface-functionalized Mg1-xCoxFe2O4 nanoparticles were synthesized and their structural and magnetic properties were studied for their potential use as MRI contrast agents and for thermotherapeutic applications. The results showed that the lattice parameter, crystallite size, and force constants of the nanoparticles changed with the cobalt content. The Mossbauer spectra and M-H hysteresis loops confirmed the transition in magnetic relaxation behavior with changing cobalt content. Cytotoxicity experiments also demonstrated the biocompatibility of the nanoparticles. Both r(2) and SLP increased with cobalt content in the Mg1-xCoxFe2O4 series due to the increased magnetization and anisotropy.
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
Chemistry, Multidisciplinary
J. Lohr, M. Vasquez Mansilla, M. V. Gerbaldo, M. S. Moreno, D. Tobia, G. F. Goya, E. L. Winkler, R. D. Zysler, E. Lima
Summary: The thermal decomposition of organometallic precursors in the presence of surfactants and a long-chain alcohol is a valuable method to synthesize magnetic nanoparticles with control over morphology and crystallinity. The pre-decomposition step at 373-393 K in inert gas flux plays a crucial role in determining the composition and morphology of the final nanoparticles, such as Fe1-yO/Fe3O4 core-shell structure and 20-25 nm size, versus monophasic MNPs of 11 nm with ferrite structure obtained when skipping this step. The differences in composition significantly affect the resulting magnetic properties of MNPs, which are related to by-reactions in the synthesis solution during preparation.
JOURNAL OF NANOPARTICLE RESEARCH
(2021)
Article
Chemistry, Physical
Xiang Yu, Tianyu Yang, Chenhui Lv, Lichen Wang, Ruoshui Liu, Di'an Wu, Daming Tian, Shuli He
Summary: 10-nm MnxFe3-xO4 (x = 0, 0.3, 0.7) magnetic nanoparticles with single cubic structure were synthesized by thermal decomposition method. The magnetic properties and cation oxidation state of the nanoparticles were investigated. Mn doping induced lattice expansion and the fraction of Mn2+ and Mn3+ in the nanoparticles varied with different Mn concentrations. The saturation magnetization of the nanoparticles decreased with increasing Mn concentration due to lattice distortion, while preserving a constant value for Mn0.3Fe2.7O4 nanoparticles. Increasing the ratio of Mn2+ and avoiding lattice distortion are beneficial for improving the magnetic properties of manganese ferrite. In addition, Mn0.3Fe2.7O4 @SiO2 nanoparticles showed good magnetic hyperthermia properties in vitro.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Biochemistry & Molecular Biology
Rocio Redon, Miriam D. Aviles-Avila, Leopoldo Ruiz-Huerta, Herlinda Montiel, Alex Elias-Zuniga, Lucy-Caterine Daza-Gomez, Oscar Martinez-Romero
Summary: By utilizing additive manufacturing and nanotechnology, magnetic cobalt ferrite and barium ferrite nanoparticles were incorporated into commercial resins and successfully transferred their magnetic properties to the final 3D-printed pieces through photopolymerization.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Chemistry, Multidisciplinary
Thomas Girardet, Pierre Venturini, Herve Martinez, Jean-Charles Dupin, Franck Cleymand, Solenne Fleutot
Summary: Nanoparticles have gained increasing interest due to the development of new synthesis methods and analysis tools with high spatial resolution. This review focuses on magnetic iron oxide nanoparticles, discussing their magnetic properties, synthesis and washing methods, and functionalization strategies developed by the research team.
APPLIED SCIENCES-BASEL
(2022)
Article
Nanoscience & Nanotechnology
Julia Nowak-Jary, Beata Machnicka
Summary: Magnetic iron oxide nanoparticles have broad potential applications in medical and biological sciences. They can be used in targeted drug delivery, internal radiotherapy, magnetic resonance imaging, hyperthermia, and radiolabelling. The appropriate design of nanoparticles allows them to be delivered to desired tissues and organs, with an external magnetic field increasing their biodistribution. Factors such as size, shape, surface charge, coating molecules, and route of administration affect their biodistribution. Modern techniques can determine nanoparticle accumulation sites and concentration in isolated tissues or the body in vivo.
INTERNATIONAL JOURNAL OF NANOMEDICINE
(2023)
Article
Engineering, Electrical & Electronic
O. Ramanjaneyulu, N. Suresh Kumar, D. Baba Basha, K. Chandra Babu Naidu
Summary: A series of Ba1-xCuxFe12O19 (x = 0.2, 0.4, 0.6, and 0.8) (BFCU) nanoparticles were synthesized via hydrothermal method at low temperatures. The nanoparticles exhibited a hexagonal structure confirmed by X-ray diffraction patterns. The surface morphology analysis revealed the presence of nanospheres. Dielectric constant versus frequency plots indicated the Maxwell-Wagner's interfacial polarization. The samples with x = 0.2-0.8 exhibited well-defined hysteresis behavior in the M-H loops. The saturation magnetization was determined using the law of approach saturation (LAS) plots. Weight loss, crystallization, transition, and melting temperatures were obtained from TG-DTG and TG-DSC plots.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Chemistry, Physical
M. Ounacer, B. Rabi, A. Essoumhi, M. Sajieddine, B. F. O. Costa, M. Emo, A. Razouk, M. Sahlaoui
Summary: The report investigates the structural and magnetic properties of Al3+ substituted cobalt ferrite nanoparticles. It demonstrates that increasing Al content significantly influences the lattice parameters and magnetic properties, leading to a decrease in grain size.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Crystallography
Mohamed S. A. Darwish
Summary: This study fabricated a series of photocatalysts based on magnetic ferrite nanostructures using a two-step co-precipitation technique. The fabricated magnetic photocatalysts were characterized using various methods. The results showed that MNPs exhibited outstanding performance as magnetic photocatalysts for the water-splitting process.
Article
Chemistry, Multidisciplinary
Guanping Li, Olaf Stefanczyk, Kunal Kumar, Yuuki Mineo, Koji Nakabayashi, Shin-ichi Ohkoshi
Summary: In this study, six new high-dimensional frameworks were successfully synthesized by self-assembly of Fe-II complexes of phenazine, quinoxaline, and 4,4'-trimethylenedipyridine with tetrahedral building blocks of [Hg-II(XCN)(4)](2-) (X=S or Se). Compounds 1, 3, and 3-Se exhibited intense sub-terahertz (sub-THz) absorbance, while compounds 1, 4, and 4-Se showed low-frequency Raman scattering. These findings suggest that heavy metal Fe-II-Hg-II systems are promising platforms for constructing sub-THz absorbers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Guanping Li, Olaf Stefanczyk, Kunal Kumar, Koji Nakabayashi, Shin-ichi Ohkoshi
Summary: This research successfully synthesized two self-assembled complexes composed of iron(II) and tetra(thiocyanato)mercury(II) ions. These complexes showed similar physicochemical properties with subtle differences. Additionally, one of the complexes exhibited nonlinear optical activity. Magnetic studies revealed the presence of high-spin iron(II) ions and provided information about the orientation of their magnetic anisotropy vectors.
INORGANIC CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Kunal Kumar, Guanping Li, Olaf Stefanczyk, Szymon Chorazy, Koji Nakabayashi, Shin-ichi Ohkoshi
Summary: Coordination network-based magnets composed of uncommon Kramers ions (Nd(iii) and Sm(iii)) exhibit emissive properties and may realize diverse magneto-optical applications. The cyanide-bridged robust networks possessing lanthanide ions exhibit tricapped trigonal prism coordination geometry and single-molecule magnet (SMM) properties. The compounds also show visible emissions and SmAu displays the highest relative thermal sensitivity among Sm(iii)-containing SMMs in a 3D framework, making it suitable for thermal sensing applications.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Inorganic & Nuclear
Kazuki Nakamura, Koji Nakabayashi, Kenta Imoto, Shin-ichi Ohkoshi
Summary: A two-dimensional cyanido-bridged Co-W assembly with layer structure was synthesized, showing a charge transfer-induced phase transition and drastic color change. The compound exhibits a wide thermal hysteresis loop and bistability at room temperature.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Jessica MacDougall, Asuka Nama, Maric Yoshikiyo, Shin-ichi Ohkoshi
Summary: In this study, a seed-mediated method for generating ε-Fe2O3 is reported. By using c-Fe2O3 nanoparticles as seeds and calcining Prussian blue (PB) through a proliferative reaction, the generation of c-Fe2O3 can be accelerated. The synthetic reaction can be carried out at a temperature below 300 degrees C, suggesting its potential for low-temperature synthesis of ε-Fe2O3.
Article
Chemistry, Multidisciplinary
Tomasz Charytanowicz, Katarzyna Dziedzic-Kocurek, Kunal Kumar, Shin-ichi Ohkoshi, Szymon Chorazy, Barbara Sieklucka
Summary: The combination of iron-(II) perchlorate with the octacyanidorhenate-(V) ions and two isomers of benzylpyridine results in heterometallic cyanido-bridged frameworks. The structure and physical properties of these frameworks are determined by the position of the benzyl substituent of the pyridine ligand. The coordination layers formed by 3-benzylpyridine do not exhibit significant thermal spin crossover, while the chiral three-dimensional coordination network formed by 4-benzylpyridine displays thermal spin transition of Fe-(II) sites.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Shintaro Akagi, Junhao Wang, Kenta Imoto, Shin-ichi Ohkoshi, Hiroko Tokoro
Summary: Crystal engineering has led to the synthesis of a new ionic chain magnet, NiW, which contains anionic cyanido-bridged chains and cationic mononuclear complexes. The compound exhibits ferromagnetic coupling within the chain but antiferromagnetic interaction between chains. This antiferromagnetic interaction can be overcome by applying an external magnetic field, resulting in a spin-flop transition. The unique metamagnetic behavior is attributed to the interaction between the complexes and chains.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Inorganic & Nuclear
Yusuke Ikeda, Daiju Matsumura, Takuya Tsuji, Asuka Namai, Kenta Imoto, Hiroko Tokoro, Koji Nakabayashi, Shin-ichi Ohkoshi
Summary: A film of a cyanido-bridged Cu-Mo assembly with a monoclinic structure has been electrochemically synthesized. Extended X-ray absorption fine structure analysis reveals the bond distances around the Cu site. The film exhibits photo-switchable magnetization and dielectric relaxation related to the hydrogen bond network.
INORGANICA CHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Shintaro Akagi, Junhao Wang, Kenta Imoto, Kunal Kumar, Shin-ichi Ohkoshi, Hiroko Tokoro
Summary: By crystal engineering, unique magnetic functionalities can be intentionally designed in molecular magnets. In this study, a novel two-dimensional cyanido-bridged coordination network, [Ni-II(pz)(4)]{[Ni-II(pz)(3)][W-V(CN)(8)]}(2)& BULL;3.5H(2)O (NiW, pz = pyrazole), with metamagnetic behavior was synthesized. NiW has wavy coordination layers consisting of two differently sized molecular square ladders and exhibits strong intralayer ferromagnetic interactions. However, due to the relatively short interlayer distance, NiW shows spontaneous antiferromagnetic ordering below a Neel temperature of 21 K. By applying an external magnetic field, such antiferromagnet can be converted into a ferromagnet with a coercive field of 600 Oe at 2 K, elucidating the metamagnetic behavior of NiW.
PURE AND APPLIED CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Shin-ichi Ohkoshi, Marie Yoshikiyo, Jessica MacDougall, Yusuke Ikeda, Hiroko Tokoro
Summary: Effective reuse of waste heat energy is crucial for green transformation and energy saving. Traditional phase-change heat storage materials have limitations in storing energy for an extended period. However, the concept of long-term heat-storage materials, which can preserve thermal energy and release it on demand, opens up new possibilities. This feature article discusses the discovery, heat-storage properties, and potential applications of long-term heat-storage ceramics made of lambda-trititanium-pentoxide (lambda-Ti3O5).
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Guanping Li, Olaf Stefanczyk, Kunal Kumar, Kenta Imoto, Koji Nakabayashi, Shin-ichi Ohkoshi
Summary: The development of optical and vibrational spin-crossover thermometers has significant implications for practical applications and contributes to the advancement of advanced thermometers.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Shoma Shimizu, Asuka Namai, Shin-ichi Ohkoshi
Summary: This study investigates the particle size effect on millimeter-wave absorption of gallium-substituted epsilon iron oxide. The results show that as the particle size increases, the millimeter-wave absorption and Faraday rotation increase, indicating a significant influence of particle size on millimeter-wave absorption.
