Magnetochemistry

12 pages, 3515 KB

Open AccessArticle

Magnetic Properties and Coercivity Mechanism of Nanocrystalline Rare-Earth-Free Co₇₄Zr₁₆Mo₄Si₃B₃ Alloys

by Aida Miranda and Israel Betancourt

Magnetochemistry 2025, 11(9), 78; https://doi.org/10.3390/magnetochemistry11090078 - 2 Sep 2025

The microstructure and magnetic properties of rare-earth-free, melt-spun Co₇₄Zr₁₆Mo₄Si₃B₃ alloys were investigated to enhance their hard magnetic response and elucidate their coercivity mechanism. The alloys exhibit a polycrystalline microstructure composed of randomly oriented, equiaxed [...] Read more.

The microstructure and magnetic properties of rare-earth-free, melt-spun Co₇₄Zr₁₆Mo₄Si₃B₃ alloys were investigated to enhance their hard magnetic response and elucidate their coercivity mechanism. The alloys exhibit a polycrystalline microstructure composed of randomly oriented, equiaxed grains, predominantly comprising the rhombohedral hard magnetic Co₁₁Zr₂ phase (92.4 wt.%). These materials display a favorable combination of magnetic properties, with coercive fields up to 581 kA/m, maximum magnetization reaching 0.30 T, and Curie temperatures as high as 751 K. An interpretation of the results, based on microstructural features, intrinsic magnetic parameters, and micromagnetic simulations, indicates that the coercivity mechanism of these melt-spun alloys can be attributed to the nucleation of reverse magnetic domains. Full article

(This article belongs to the Section Magnetic Materials)

► Show Figures

Figure 1

26 pages, 10898 KB

Open AccessReview

Molecular Nanomagnets with Photomagnetic Properties: Design Strategies and Recent Advances

by Xiaoshuang Gou, Xinyu Sun, Peng Cheng and Wei Shi

Magnetochemistry 2025, 11(9), 77; https://doi.org/10.3390/magnetochemistry11090077 - 31 Aug 2025

Abstract

The magnetic properties of molecular nanomagnets can be finely modulated by light, which provides great potential in optical switches, smart sensors, and data storage devices. Light-induced spin transition, structure changes, and radical formation could tune the static and dynamic magnetic properties of molecular [...] Read more.

The magnetic properties of molecular nanomagnets can be finely modulated by light, which provides great potential in optical switches, smart sensors, and data storage devices. Light-induced spin transition, structure changes, and radical formation could tune the static and dynamic magnetic properties of molecular nanomagnets with high spatial and temporal resolutions. Herein, we summarize the design strategies of photoresponsive molecular nanomagnets and review the recent advances in transition metal/lanthanide molecular nanomagnets with photomagnetic properties. The photoresponsive mechanism based on spin transition, photocyclization, and photogenerated radicals is discussed in detail, providing insights into the photomagnetic properties of molecular nanomagnets for advanced photoresponsive materials. Full article

(This article belongs to the Special Issue Molecular Magnetism: A Themed Issue in Honor of Professor Dai-Zheng Liao on the Occasion of His 85th Birthday)

► Show Figures

Figure 1

5 pages, 172 KB

Open AccessEditorial

Advances in Functional Magnetic Nanomaterials for Water Pollution Control

by Wei Ding and Huaili Zheng

Magnetochemistry 2025, 11(9), 76; https://doi.org/10.3390/magnetochemistry11090076 - 27 Aug 2025

Abstract

The application of magnetism in water treatment processes has enhanced efficiency across various stages, including coagulation, flocculation, sedimentation, and filtration, representing a field with significant potential [...] Full article

(This article belongs to the Special Issue Applications of Magnetic Materials in Water Treatment)

12 pages, 2631 KB

Open AccessArticle

A Dy₂ Complex Constructed by TCNQ^·− Radical Anions with Slow Magnetic Relaxation Behavior

by Xirong Wang, Shijia Qin, Xiulan Li, Wenjing Zuo, Qinglun Wang, Licun Li, Yue Ma, Jinkui Tang and Bin Zhao

Magnetochemistry 2025, 11(9), 75; https://doi.org/10.3390/magnetochemistry11090075 - 26 Aug 2025

Abstract

A centrosymmetric dinuclear complex, [Dy₂(H₂dapp)₂(μ-OH)₂(H₂O)₂]·4TCNQ·2CH₃OH, was synthesized using the TCNQ^·− radical anion (TCNQ = 7,7,8,8-tetracyanoquino-dimethane) and pentadentate nitrogen-containing Schiff base ligand (H₂dapp = 2,6-diacetylpyridine)-bis(2-pyridylhydrazone). [...] Read more.

A centrosymmetric dinuclear complex, [Dy₂(H₂dapp)₂(μ-OH)₂(H₂O)₂]·4TCNQ·2CH₃OH, was synthesized using the TCNQ^·− radical anion (TCNQ = 7,7,8,8-tetracyanoquino-dimethane) and pentadentate nitrogen-containing Schiff base ligand (H₂dapp = 2,6-diacetylpyridine)-bis(2-pyridylhydrazone). In the Dy₂ dimer, the two Dy^III ions adopt eight-coordinated geometries intermediate between D_4d and D_2d symmetries, linked by two OH⁻ groups, with ferromagnetic Dy-Dy interactions. The TCNQ^·− radical anions are uncoordinated, and they pack tightly into antiparamagnetic dimers to balance the system charge. Under zero field, weak magnetic relaxation was observed, with an approximate Δ_eff = 2.82 K and τ₀ = 6.88 × 10⁻⁶ s. This might be attributed to the short intermolecular Dy···Dy distance of 7.97 Å, which could enhance intermolecular dipolar interactions and quantum tunneling of magnetization (QTM). Full article

(This article belongs to the Special Issue Molecular Magnetism: A Themed Issue in Honor of Professor Dai-Zheng Liao on the Occasion of His 85th Birthday)

► Show Figures

Figure 1

13 pages, 1365 KB

Open AccessArticle

Effect of Microstructural Changes on the Magnetization Dynamics Mechanisms in Ferrofluids Subjected to Alternating Magnetic Fields

by Cristian E. Botez and Zachary Musslewhite

Magnetochemistry 2025, 11(9), 74; https://doi.org/10.3390/magnetochemistry11090074 - 24 Aug 2025

Abstract

We investigated the effects of chemical and physical changes on the interplay between the Néel and Brown superspin relaxation mechanisms in ferrofluids containing 18 nm-diameter Co_0.2Fe_2.8O₄ magnetic nanoparticles. We attempted to tune the ferrofluid’s magnetization dynamics via three [...] Read more.

We investigated the effects of chemical and physical changes on the interplay between the Néel and Brown superspin relaxation mechanisms in ferrofluids containing 18 nm-diameter Co_0.2Fe_2.8O₄ magnetic nanoparticles. We attempted to tune the ferrofluid’s magnetization dynamics via three methods: (i) changing the carrier fluid from Isopar M to kerosene (ii) doubling the Co-doping level from x = 0.2 to x = 0.4, and (iii) diluting the Co_0.2Fe_2.8O₄/Isopar M nanomagnetic fluid from δ = 1 mg/mL to δ = 0.1 mg/mL. We used temperature-resolved ac-susceptibility measurements at different frequencies, χ″ vs. T|_f, to gain insight into the thermally driven superspin dynamics of the nanoparticles within the ferrofluid. Our data demonstrates that both increasing x and using a different carrier fluid quantitatively alter the temperature dependence of the Néel and Brown relaxation frequency (f_N vs. T and f_B vs. T) by changing the nanoparticles’ magnetic moments and the fluid’s viscosity. Yet, the two mechanisms remain decoupled, as indicated by the presence of two magnetic events (peaks in the χ″ vs. T|_f datasets) one corresponding to the Néel and the other to Brown relaxation. On the other hand, diluting the ferrofluid leads to a qualitative change in the collective superspin dynamics behavior. Indeed, there is just one χ″-peak in the data from the δ = 0.1 mg/mL nanofluid, and its f vs. T dependence is well-described by a model that includes coupled contributions from both the Néel and Brown relaxation:

f (T) = p \cdot \frac{T}{γ_{0}} \cdot e x p [- \frac{E^{'}}{k_{B} (T - T_{0}^{'})}] +

(1 − p)

f_{0} e x p [- \frac{E_{B}}{k_{B} (T - T_{0})}]

. This is a remarkable behavior that demonstrates the ability to control a ferrofluids magnetization dynamics through simple chemical and physical changes. Full article

(This article belongs to the Special Issue Ferrofluids: Electromagnetic Properties and Applications)

► Show Figures

Figure 1

13 pages, 4868 KB

Open AccessArticle

A Dinuclear Dysprosium(III) Single Molecule Magnet of Benzo[h]quinolin-10-ol

by Limin Zhou, Hongling Lv, Yuning Liang, Dongcheng Liu, Zaiheng Yao, Shuchang Luo and Zilu Chen

Magnetochemistry 2025, 11(9), 73; https://doi.org/10.3390/magnetochemistry11090073 - 24 Aug 2025

Abstract

To develop single molecule magnets, a dinuclear complex [Dy₂(HOBQ)₄Cl₆] (1) was prepared from the reaction of DyCl₃ with benzo[h]quinolin-10-ol (HOBQ). Each Dy(III) ion shows a compressed octahedral geometry and the two Dy(III) [...] Read more.

To develop single molecule magnets, a dinuclear complex [Dy₂(HOBQ)₄Cl₆] (1) was prepared from the reaction of DyCl₃ with benzo[h]quinolin-10-ol (HOBQ). Each Dy(III) ion shows a compressed octahedral geometry and the two Dy(III) ions in 1 are bridged by two Cl⁻ ligands to construct a dinuclear structure with the four HOBQ ligands on the axial positions and six Cl⁻ ligands in the equatorial plane. Magnetic measurements showed that complex 1 is a field-induced single molecule magnet having an obvious magnetic hysteresis loop with an energy barrier of 71(2) K. These experimental results are corroborated by the ab initio complete active space self-consistent field (CASSCF) calculations which also interpret the magneto-structural correlation. It is a typical example to achieve Dy(III) SMM through regulating coordination geometry, i.e., lengthening equatorial coordination bonds and shortening axial ones to form a compressed octahedral geometry. Full article

(This article belongs to the Special Issue Molecular Magnetism: A Themed Issue in Honor of Professor Dai-Zheng Liao on the Occasion of His 85th Birthday)

► Show Figures

Figure 1

18 pages, 5350 KB

Open AccessArticle

Mössbauer Research and Magnetic Properties of Dispersed Microspheres from High-Calcium Fly Ash

by Elena V. Fomenko, Yuriy V. Knyazev, Galina V. Akimochkina, Sergey V. Semenov, Vladimir V. Yumashev, Leonid A. Solovyov, Natalia N. Anshits, Oleg A. Bayukov and Alexander G. Anshits

Magnetochemistry 2025, 11(9), 72; https://doi.org/10.3390/magnetochemistry11090072 - 23 Aug 2025

Abstract

High-calcium fly ash (HCFA), produced from the lignite combustion, has emerged as a global concern due to its fine particle size and adverse environmental impacts. This study presents the characteristics of dispersed microspheres from HCFA obtained using modern techniques, such as XRD, SEM-EDS, [...] Read more.

High-calcium fly ash (HCFA), produced from the lignite combustion, has emerged as a global concern due to its fine particle size and adverse environmental impacts. This study presents the characteristics of dispersed microspheres from HCFA obtained using modern techniques, such as XRD, SEM-EDS, ⁵⁷Fe Mössbauer spectroscopy, DSC-TG, particle size analysis, and magnetic measurements. It is found that an increase in microsphere size is likely due to the growth of the silicate glass-like phase, while the magnetic crystalline phase content remains stable. According to the ⁵⁷Fe Mössbauer spectroscopy, there are two substituted Ca-based ferrites—CaFe₂O₄ and Ca₂Fe₂O₅ with a quite different magnetic behavior. Besides, the magnetic ordering temperature of the brownmillerite (Ca₂Fe₂O₅) phase increases with the average diameter of the microspheres. FORC analysis reveals enhanced magnetic interactions as microsphere size increases, indicating an elevation in the concentration of magnetic microparticles, primarily on the microsphere surface, as supported by electron microscopy data. The discovered the magnetic crystallographic phases distribution on the microsphere’s surface claims the accessibility for further enrichment of the magnetically active particles and the possible application of fly ashes as a cheap source for magnetic materials synthesis. Full article

► Show Figures

Figure 1

26 pages, 4255 KB

Open AccessReview

Application Progress of Magnetic Chitosan in Heavy Metal Wastewater Treatment

by Xiaotian Wang, Yan Zhuang, Kinjal J. Shah and Yongjun Sun

Magnetochemistry 2025, 11(9), 71; https://doi.org/10.3390/magnetochemistry11090071 - 22 Aug 2025

Abstract

Wastewater containing heavy metals can come from a variety of sources and is extremely toxic and hard to break down. Conventional treatment methods can easily result in secondary pollution and are expensive. The research on magnetic chitosan composites, a new adsorbent in the [...] Read more.

Wastewater containing heavy metals can come from a variety of sources and is extremely toxic and hard to break down. Conventional treatment methods can easily result in secondary pollution and are expensive. The research on magnetic chitosan composites, a new adsorbent in the treatment of heavy metal wastewater, is methodically reviewed in this paper. It offers a theoretical foundation for the creation of more environmentally friendly and effective wastewater treatment technology by examining its preparation and modification technology, adsorption mechanism, and application performance. This paper provides a summary of the technology used to prepare and modify magnetic chitosan composites. Both the cross-linking and co-precipitation methods are thoroughly examined. A summary of the fundamental process of heavy metal ion adsorption is provided, along with information on the chemical and physical impacts. Of these, chemical adsorption has been shown to work well with the majority of heavy metal adsorption systems. According to application research, magnetic chitosan exhibits good adaptability in real-world industrial wastewater treatment and has outstanding adsorption performance for various heavy metal ion types and multi-metal coexistence systems (including synergistic/competitive effects). Lastly, the optimization of the material preparation and modification process, the mechanism influencing the various coexisting ion types, and the improvement of regeneration ability should be the main areas of future development. Full article

(This article belongs to the Section Applications of Magnetism and Magnetic Materials)

► Show Figures

Figure 1

16 pages, 1626 KB

Open AccessArticle

Enhanced Magnetocaloric Effect and Single-Molecule Magnet Behavior in a Series of Sulfur-Containing Ligand-Based Ln₉ Clusters (Ln = Gd, Tb, and Dy)

by Ya-Wei Geng, Tong Guo, Xiao-Qin Wang and Tian Han

Magnetochemistry 2025, 11(9), 70; https://doi.org/10.3390/magnetochemistry11090070 - 22 Aug 2025

Abstract

As an important branch of lanthanide-based complexes, clusters show unique properties in magnetocaloric effect (MCE) and single-molecule magnets (SMMs) using O/N ligands, while research on heavy p-block elements (e.g., S atom) with larger atomic radii and more diffuse p valence orbitals as coordinating [...] Read more.

As an important branch of lanthanide-based complexes, clusters show unique properties in magnetocaloric effect (MCE) and single-molecule magnets (SMMs) using O/N ligands, while research on heavy p-block elements (e.g., S atom) with larger atomic radii and more diffuse p valence orbitals as coordinating atoms remains relatively scarce. Herein, using the sulfur-containing ligand of 2-pyridinethiol 1-oxide (HL), we successfully synthesized a series of hourglass-like Ln₉ clusters [Ln₉(L)₁₇(μ₃-OH)₉(μ₄-OH)]·nH₂O (1: Ln = Gd, n = 3; 2: Ln = Tb, n = 3; 3: Ln = Dy, n = 1). Magnetic data analysis reveals that cluster 1 shows a significant MCE, with the entropy change (−ΔS_m) reaching a maximum of 34.41 J kg⁻¹ K⁻¹ at 2 K under ΔH = 7 T. Cluster 3, meanwhile, exhibits distinct frequency- and temperature-dependent behavior, indicating its SMM characteristics. Interestingly, despite possessing the highest molar mass among reported Gd₉ clusters with MCE, 1 exhibits a competitive −ΔS_m value, highlighting the critical role of sulfur-containing ligand on the structure and even exchange interactions. This work offers new insights into synthesizing high-performance MCE materials and understanding magneto-structural relationships. Full article

(This article belongs to the Special Issue Molecular Magnetism: A Themed Issue in Honor of Professor Dai-Zheng Liao on the Occasion of His 85th Birthday)

► Show Figures

Figure 1

13 pages, 1570 KB

Open AccessArticle

Refrigeration in Adiabatically Confined Anisotropic Transition Metal Complexes Induced by Sudden Magnetic Field Quenching

by Andrew Palii, Valeria Belonovich and Boris Tsukerblat

Magnetochemistry 2025, 11(8), 69; https://doi.org/10.3390/magnetochemistry11080069 - 15 Aug 2025

Abstract

The article is devoted to the theoretical development of the mechanisms of molecular refrigeration, the area combining molecular magnetism and material science with promise for low-temperature physics and quantum computing, where conventional principles of refrigeration become inefficient. Given this general trend, we propose [...] Read more.

The article is devoted to the theoretical development of the mechanisms of molecular refrigeration, the area combining molecular magnetism and material science with promise for low-temperature physics and quantum computing, where conventional principles of refrigeration become inefficient. Given this general trend, we propose the concept of the magnetothermal effect in magnetically anisotropic complexes of 3d metal ions, caused by fast magnetic field quenching. Within this concept, the most topical case of an axially magnetically anisotropic system isolated from the environment by adiabatic envelope is analyzed. We evaluate the temperature change as a function of the initial temperature and magnetic field and also its dependence on the sign and the magnitude of the axial zero-field splitting parameter and the Debye temperature. Correlations are revealed between the sign of the magnetic anisotropy (dictated by the sign of the axial zero field splitting parameter) and the sign of the thermal effect (heating versus cooling) caused by field quenching. The temperature change is shown to be negative (cooling) in the case of complexes exhibiting easy-axis-type magnetic anisotropy, while for the case of easy-plane-type anisotropy, it proves to be positive (heating). The thermal effects are shown to have an efficient control by varying the initially applied field. These findings allow us to propose complexes exhibiting easy-axis-type magnetic anisotropy as candidates for achieving a low-temperature refrigeration effect caused by fast field quenching and also to employ the established magnetothermal correlations to the analysis of magnetic anisotropy. Full article

(This article belongs to the Special Issue Stimuli-Responsive Magnetic Molecular Materials—2nd Edition)

► Show Figures

Figure 1

15 pages, 2189 KB

Open AccessArticle

Synthesis, Crystal Structures and Magnetic Properties of Lanthanide Complexes with Rhodamine Benzoyl Hydrazone Ligands

by Lin Miao, Dong-Mei Zhu, Cai-Ming Liu, Yi-Quan Zhang and Hui-Zhong Kou

Magnetochemistry 2025, 11(8), 68; https://doi.org/10.3390/magnetochemistry11080068 - 7 Aug 2025

Abstract

Given the outstanding magnetic characteristics of lanthanide ions, the development of mononuclear or multinuclear lanthanide complexes becomes imperative. Previous research showed that a series of mononuclear Dy(III) complexes of rhodamine benzoyl hydrazone Schiff base ligands exhibit remarkable single-molecule magnetic properties and fluorescence. In [...] Read more.

Given the outstanding magnetic characteristics of lanthanide ions, the development of mononuclear or multinuclear lanthanide complexes becomes imperative. Previous research showed that a series of mononuclear Dy(III) complexes of rhodamine benzoyl hydrazone Schiff base ligands exhibit remarkable single-molecule magnetic properties and fluorescence. In this study, we used analogous ligands to synthesize lanthanide complexes [Dy(HL¹-o)(NO₃)₂(CH₃OH)₂]NO₃·CH₃OH (complex 1·MeOH) and tetranuclear complexes [Ln₄(L¹-c)₂(L²)₂(μ₃-OH)₂(NO₃)₂(CH₃OH)₄](NO₃)₂·2CH₃CN·5CH₃OH·2H₂O (Ln = Dy, complex 2; Ln = Gd, complex 3). Magnetic susceptibility measurements show that 1·2H₂O is a single-molecule magnet, 2 shows slow magnetic relaxation and 3 is a magnetic cooling material with the magnetic entropy change of 9.81 J kg⁻¹ K⁻¹ at 2 K and 5 T. The theoretical calculations on 1·MeOH indicate that it shows good magnetic anisotropy with the calculated energy barrier of 194.6 cm⁻¹. Full article

(This article belongs to the Special Issue Molecular Magnetism: A Themed Issue in Honor of Professor Dai-Zheng Liao on the Occasion of His 85th Birthday)

► Show Figures

Figure 1

10 pages, 2101 KB

Open AccessArticle

Structural and Ferromagnetic Response of B2-Type Al₄₅Mn_41.8X_13.2 (X = Fe, Co, Ni) Alloys

by Esmat Dastanpour, Haireguli Aihemaiti, Shuo Huang, Valter Ström, Lajos Károly Varga and Levente Vitos

Magnetochemistry 2025, 11(8), 67; https://doi.org/10.3390/magnetochemistry11080067 - 6 Aug 2025

Abstract

To our knowledge, no magnetic B2 phase in the Al–Mn system of near-equiatomic compositions has been reported so far. Here, we investigate the structural and magnetic characteristics of Al₄₅Mn_41.8X_13.2 (X = Fe, Co or Ni) alloys. We demonstrate [...] Read more.

To our knowledge, no magnetic B2 phase in the Al–Mn system of near-equiatomic compositions has been reported so far. Here, we investigate the structural and magnetic characteristics of Al₄₅Mn_41.8X_13.2 (X = Fe, Co or Ni) alloys. We demonstrate that adding 13.2 atomic percent magnetic 3d metal to AlMn stabilizes a ferromagnetic B2 structure, where Al and X occupy different sublattices. We employ density functional theory calculations and experimental characterizations to underscore the role of the late 3d metals for the phase stability of the quasi-ordered ternary systems. We show that these alloys possess large local magnetic moments primarily due to Mn atoms partitioned to the Al-free sublattice. The revealed magneto-chemical effect opens alternative routes for tailoring the magnetic properties of B2 intermetallic compounds for various magnetic applications. Full article

(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)

► Show Figures

Figure 1

4 pages, 140 KB

Open AccessEditorial

Computational Chemistry in Nuclear Magnetic Resonance

by Irina L. Rusakova and Yuriy Yu. Rusakov

Magnetochemistry 2025, 11(8), 66; https://doi.org/10.3390/magnetochemistry11080066 - 4 Aug 2025

Abstract

Determining molecular structure via nuclear magnetic resonance (NMR) spectral analysis has become an integral part of physical–chemical research in organic and inorganic chemistry [...] Full article

(This article belongs to the Special Issue Computational Chemistry in Nuclear Magnetic Resonance)

21 pages, 5366 KB

Open AccessArticle

Multifaceted Analysis of Pr₂Fe_16.75Ni_0.25 Intermetallic Compound: Crystallographic Insights, Critical Phenomena, and Thermomagnetic Behavior near Room Temperature

by Jihed Horcheni, Hamdi Jaballah, Sirine Gharbi, Essebti Dhahri and Lotfi Bessais

Magnetochemistry 2025, 11(8), 65; https://doi.org/10.3390/magnetochemistry11080065 - 31 Jul 2025

Abstract

The alloy Pr₂Fe_16.75Ni_0.25 has been examined to investigate its structural properties, critical behavior, and magnetocaloric effects. Rietveld’s refinement of X-ray diffraction patterns has revealed a rhombohedral structure with an

R \bar{3} m

space group. Pr₂Fe [...] Read more.

The alloy Pr₂Fe_16.75Ni_0.25 has been examined to investigate its structural properties, critical behavior, and magnetocaloric effects. Rietveld’s refinement of X-ray diffraction patterns has revealed a rhombohedral structure with an

R \bar{3} m

space group. Pr₂Fe_16.9Ni_0.25 also demonstrates a direct magnetocaloric effect near room temperature, accompanied by a moderate magnetic entropy change (

- Δ S_{M}^{\max}

= 5.5 J kg⁻¹ K⁻¹ at

μ_{0} Δ H = 5

T) and a broad working temperature range. Furthermore, the Relative Cooling Power (RCP) is approximately 89% of the widely recognized gadolinium (Gd) for

μ_{0} Δ H = 2

T. This compound exhibits a commendable magnetocaloric response, on par with or even surpassing that of numerous other intermetallic alloys. Critical behavior was analyzed using thermo-magnetic measurements, employing methods such as the modified Arrott plot, critical isotherm analysis, and Kouvel-Fisher techniques. The obtained critical exponents (

β

,

γ

, and

δ

) exhibit similarities to those of the 3D-Ising model, characterized explicitly by intermediate range interactions. Full article

► Show Figures

Figure 1

3 pages, 142 KB

Open AccessEditorial

Magnetism: Energy, Recycling, Novel Materials

by Joan-Josep Suñol

Magnetochemistry 2025, 11(8), 64; https://doi.org/10.3390/magnetochemistry11080064 - 31 Jul 2025

Abstract

Magnetism is a field of physics that should be developed within this century in order to enhance its applicability [...] Full article

(This article belongs to the Special Issue Magnetism: Energy, Recycling, Novel Materials)

14 pages, 4243 KB

Open AccessArticle

Evaluation of the Effects of Food and Fasting on Signal Intensities from the Gut Region in Mice During Magnetic Particle Imaging (MPI)

by Saeed Shanehsazzadeh and Andre Bongers

Magnetochemistry 2025, 11(8), 63; https://doi.org/10.3390/magnetochemistry11080063 - 25 Jul 2025

Abstract

Gastrointestinal signals present a major challenge in magnetic particle imaging (MPI) because of their strong background interference. This study aimed to evaluate and compare the gut MPI signal in mice fed six commercially available diets in Australia, including Gordon’s Specialty Stock Feeds (normal [...] Read more.

Gastrointestinal signals present a major challenge in magnetic particle imaging (MPI) because of their strong background interference. This study aimed to evaluate and compare the gut MPI signal in mice fed six commercially available diets in Australia, including Gordon’s Specialty Stock Feeds (normal and low iron), Specialty Feeds (normal and low iron), a Western diet, and Gubra-Amylin NASH (GAN diet). We also assessed the impact of 24 h fasting on gut signal reduction. Each diet group included three mice, and the gut signal intensity was monitored over seven days. The results indicated that the standard diet produced signal intensities approximately eight times greater than those of the low-iron diet from specialty feeds and over eleven times greater than those of the GAN or Western diets. Notably, switching to GAN or Western diets led to a tenfold reduction in the gut signal within 24 h, a decrease comparable to that achieved by fasting. These findings suggest that dietary modification—particularly the use of low-iron diets—can effectively minimize gastrointestinal signals in MPI, reducing background interference by up to 90%. This simple dietary adjustment offers a practical and noninvasive method for improving image clarity and experimental reliability in preclinical MPI studies. Full article

► Show Figures

Figure 1

37 pages, 3791 KB

Open AccessReview

The Advancing Understanding of Magnetorheological Fluids and Elastomers: A Comparative Review Analyzing Mechanical and Viscoelastic Properties

by Salah Rouabah, Fadila-Yasmina Didouche, Abdelmalek Khebli, Salah Aguib and Noureddine Chikh

Magnetochemistry 2025, 11(8), 62; https://doi.org/10.3390/magnetochemistry11080062 - 24 Jul 2025

Abstract

Magnetorheological fluids (MRFs) and elastomers (MREs) are two types of smart materials that exhibit modifiable rheological properties in response to an applied magnetic field. Although they share a similarity in their magnetorheological response, these two materials differ in their nature, structure, and mechanical [...] Read more.

Magnetorheological fluids (MRFs) and elastomers (MREs) are two types of smart materials that exhibit modifiable rheological properties in response to an applied magnetic field. Although they share a similarity in their magnetorheological response, these two materials differ in their nature, structure, and mechanical behavior when exposed to a magnetic field. They also have distinct application differences due to their specific rheological properties. These fundamental differences therefore influence their properties and applications in various industrial fields. This review provides a synthesis of the distinct characteristics of MRFs and MREs. The differences in their composition, rheological behavior, mechanical properties, and respective applications are summarized and highlighted. This analysis will enable a comprehensive understanding of these differences, thereby allowing for the appropriate selection of the material based on the specific requirements of a given application and fostering the development of new applications utilizing these MR materials. Full article

(This article belongs to the Section Applications of Magnetism and Magnetic Materials)

► Show Figures

Figure 1

19 pages, 4583 KB

Open AccessArticle

Glutathione and Magnetic Nanoparticle-Modified Nanochannels for the Detection of Cadmium (II) in Cereal Grains

by Wei Hu, Xinyue Xiang, Donglei Jiang, Na Zhang and Lifeng Wang

Magnetochemistry 2025, 11(7), 61; https://doi.org/10.3390/magnetochemistry11070061 - 21 Jul 2025

Abstract

We developed a novel and portable magnetic nanochannel electrochemical sensor for the sensitive detection of cadmium ions (Cd²⁺), which pose serious risks to food safety and human health. The sensor was fabricated by co-modifying an anodic aluminum oxide (AAO) nanochannel membrane [...] Read more.

We developed a novel and portable magnetic nanochannel electrochemical sensor for the sensitive detection of cadmium ions (Cd²⁺), which pose serious risks to food safety and human health. The sensor was fabricated by co-modifying an anodic aluminum oxide (AAO) nanochannel membrane with a composite of glutathione (GSH) and ferric oxide nanoparticles (Fe₃O₄), denoted as GSH@Fe₃O₄. This modified membrane was then integrated with a screen-printed carbon electrode (SPCE) to construct the GSH@Fe₃O₄/GSH@AAO/SPCE sensing platform. The performance of the sensor was evaluated using differential pulse voltammetry (DPV), which demonstrated a strong linear correlation between the peak current response and the concentration of Cd²⁺ in the range of 5–120 μg/L. The calibration equation was I_DPV(μA) = −0.31 + 0.98·C_{Cd²⁺(μg/L)}, with an excellent correlation coefficient (R² = 0.999, n = 3). The calculated limit of detection (LOD) was as low as 0.1 μg/L, indicating the high sensitivity of the system. These results confirm the successful construction of the GSH@Fe₃O₄/GSH@AAO/SPCE portable nanochannel sensor. This innovative sensing platform provides a rapid, sensitive, and user-friendly approach for the on-site monitoring of heavy metal contamination in agricultural products, especially grains. Full article

► Show Figures

Figure 1

25 pages, 2780 KB

Open AccessArticle

Motion of Magnetic Microcapsules Through Capillaries in the Presence of a Magnetic Field: From a Mathematical Model to an In Vivo Experiment

by Mikhail N. Zharkov, Mikhail A. Pyataev, Denis E. Yakobson, Valentin P. Ageev, Oleg A. Kulikov, Vasilisa I. Shlyapkina, Dmitry N. Khmelenin, Larisa A. Balykova, Gleb B. Sukhorukov and Nikolay A. Pyataev

Magnetochemistry 2025, 11(7), 60; https://doi.org/10.3390/magnetochemistry11070060 - 14 Jul 2025

Abstract

In this paper, we discuss the prediction of the delivery efficiency of magnetic carriers based on their properties and field parameters. We developed a theory describing the behavior of magnetic capsules in the capillaries of living systems. A partial differential equation for the [...] Read more.

In this paper, we discuss the prediction of the delivery efficiency of magnetic carriers based on their properties and field parameters. We developed a theory describing the behavior of magnetic capsules in the capillaries of living systems. A partial differential equation for the spatial distribution of magnetic capsules has been obtained. We propose to characterize the interaction between the magnetic field and the capsules using a single vector, which we call “specific magnetic force”. To test our theory, we performed experiments on a model of a capillary bed and on a living organism with two types of magnetic capsules that differ in size and amount of magnetic material. The experimental results show that the distribution of the capsules in the field correlated with the theory, but there were fewer actually accumulated capsules than predicted by the theory. In the weaker fields, the difference was more significant than in stronger ones. We proposed an explanation for this phenomenon based on the assumption that a certain level of magnetic force is needed to keep the capsules close to the capillary wall. We also suggested a formula for the relationship between the probability of capsule precipitation and the magnetic force. We found the effective value of a specific magnetic force at which all the capsules attracted by the magnet reach the capillary wall. This value can be considered as the minimum level for the field at which it is, in principle, possible to achieve a significant magnetic control effect. We demonstrated that for each type of capsule, there is a specific radius of magnet for which the effective magnetic force is achieved at the largest possible distance from the magnet’s surface. For the capsules examined in this study, the maximum distance where the effective field can be achieved does not exceed 1.5 cm. The results of the study contribute to our understanding of the behavior of magnetic particles in the capillaries of living organisms when exposed to a magnetic field. Full article

(This article belongs to the Special Issue Fundamentals and Applications of Novel Functional Magnetic Materials)

► Show Figures

Graphical abstract

Journal Description

Magnetochemistry

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Further Information

Guidelines

MDPI Initiatives

Follow MDPI