Advances in Functional Materials with Tunable Magnetic Properties

A special issue of Magnetochemistry (ISSN 2312-7481). This special issue belongs to the section "Magnetic Materials".

Deadline for manuscript submissions: 31 August 2024 | Viewed by 8038

Special Issue Editors

1. Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, University of the Basque Country, UPV/EHU, 20018 San Sebastian, Spain
2. Department of Applied Physics I, University of the Basque Country EIG, UPV/EHU, 20018 San Sebastian, Spain
Interests: advanced magnetic materials; amorphous; nanocrystalline and granular magnetic materials; magnetic sensors; magnetic microwires; giant magnetoimpedance effect; hysteretic magnetic properties; domain wall dynamics; functional composite materials
Special Issues, Collections and Topics in MDPI journals
1. Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, University of the Basque Country, UPV/EHU, 20018 San Sebastian, Spain
2. Department of Applied Physics I, University of the Basque Country EIG, UPV/EHU, 20018 San Sebastian, Spain
Interests: magnetism and magnetic materials; ferromagnetic metallic glasses; functional (nano)composite materials; giant magne-toimpedance effect; domain wall dynamics; rapid solidification techniques; induction heating; magnetic hyperthermia; me-chanical alloying
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Functional materials with tunable magnetic properties and reduced dimensions in high demand for numerous technological applications, such as sensors, wireless nondestructive control and monitoring security electronic surveillance, microelectronics, medicine, automobile and aircraft industries, energy harvesting and conversion, home entertainment, electrical engineering, magnetic recording, magnetic memories, among others.

This Special Issue will focus on the latest scientific results and novel concepts for the development and applications of highly sensitive magnetic devices, magnetic sensing technology, basic phenomena and fundamental studies of new magnetic materials suitable for the above-mentioned applications.

The overall goal of this issue is to provide the most up-to-date information about recent developments and trends related to optimization in the processing of magnetic materials for the achievement of advanced functional properties.

We are particularly interested in and invite colleagues to submit original research articles that will fit, but are not limited to, one of the topics listed below:

  • magnetic properties;
  • magnetic anisotropy;
  • magnetic sensors;
  • smart materials and composites;
  • soft magnetic materials;
  • amorphous magnetic materials;
  • nanocrystallization;
  • rapid annealing;
  • domain wall dynamics.

Short communications, reviews, and original research articles are encouraged. We look forward to your valuable contributions to this Special Issue.

Dr. Paula Corte-Leon
Dr. Ahmed Talaat
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Magnetochemistry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (7 papers)

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Research

10 pages, 2123 KiB  
Article
Compatibility of LaFe13−x−yMnxSiyH1.6 and Eutectic Liquid GaInSn Alloy
Magnetochemistry 2024, 10(2), 13; https://doi.org/10.3390/magnetochemistry10020013 - 12 Feb 2024
Viewed by 777
Abstract
The heat transfer rate of magnetocaloric regenerators is a topic of extensive research and the cyclability of these regenerators is critical to the operation of systems with a high coefficient of performance (e.g., potentially >22, significantly higher than typical vapor compression cooling technologies). [...] Read more.
The heat transfer rate of magnetocaloric regenerators is a topic of extensive research and the cyclability of these regenerators is critical to the operation of systems with a high coefficient of performance (e.g., potentially >22, significantly higher than typical vapor compression cooling technologies). To enable a high operating frequency that will result in a high specific cooling power, the heat transfer fluid should have high thermal conductivity and lower specific heat, i.e., higher thermal diffusivity. Eutectic metal alloys possess these qualities, such as gallium–indium–tin (Galinstan), whose thermal diffusivity has been found to be approximately an order of magnitude higher than water. For this study, the effects of eutectic liquid Galinstan exposure on the phase stability of LaFe13−x−yMnxSiyH1.6 magnetocaloric powders in an active magnetic regenerator device were investigated. The powders were characterized before and after exposure to Galinstan using X-ray diffraction, in which the phases were determined using the Rietveld refinement technique and X-ray fluorescence. It was found that after Galinstan exposure, hydrogen containing phases were present in the powder, suggesting that the hydrogen was lost from the magnetocaloric phase. The magnetocaloric phase degradation indicates that the powder was incompatible with the Galinstan metal in an environment with moisture. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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24 pages, 16841 KiB  
Article
On the Magnetization and Entanglement Plateaus in One-Dimensional Confined Molecular Magnets
Magnetochemistry 2024, 10(2), 10; https://doi.org/10.3390/magnetochemistry10020010 - 01 Feb 2024
Viewed by 568
Abstract
One-dimensional (1D) magnetic systems offer rich phenomena in the quantum limit, proving more chemically accessible than zero-dimensional or higher-dimensional frameworks. Single-walled carbon nanotubes (SWCNT) have recently been used to encapsulate trimetric nickel(II) acetylacetonate [Nanoscale, 2019, 11, 10615–10621]. Here, we investigate the magnetization on [...] Read more.
One-dimensional (1D) magnetic systems offer rich phenomena in the quantum limit, proving more chemically accessible than zero-dimensional or higher-dimensional frameworks. Single-walled carbon nanotubes (SWCNT) have recently been used to encapsulate trimetric nickel(II) acetylacetonate [Nanoscale, 2019, 11, 10615–10621]. Here, we investigate the magnetization on spin chains based on nickel trimers by Matrix Product State (MPS) simulations. Our findings reveal plateaus in the exchange/magnetic-field phase diagram for three coupling configurations, showcasing effective dimeric and trimeric spin-ordering with similar or staggered entanglement across chains. These ordered states allow the qubit-like tuning of specific local magnetic moments, exhibiting disengagement or uniform coupling in entanglement plateaus. This behavior is consistent with the experimental transition from frustrated (3D) to non-frustrated (1D) molecules, corresponding to large and smaller SWCNT diameters. Our study offers insights into the potential of 1D-confined trimers for quantum computation, extending beyond the confinement of trimetric nickel-based molecules in one dimension. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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13 pages, 3035 KiB  
Article
The Magnetostriction of Amorphous Magnetic Microwires: The Role of the Local Atomic Environment and Internal Stresses Relaxation
Magnetochemistry 2023, 9(10), 222; https://doi.org/10.3390/magnetochemistry9100222 - 20 Oct 2023
Viewed by 1116
Abstract
We studied the magnetostriction coefficients, λs, Curie temperature, Tc, and their dependence on annealing conditions in Fe47Ni27Si11B13C2 and Co67Fe3.9Ni1.5B11.5 [...] Read more.
We studied the magnetostriction coefficients, λs, Curie temperature, Tc, and their dependence on annealing conditions in Fe47Ni27Si11B13C2 and Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 amorphous glass-coated microwires with rather different character of hysteresis loops. A positive λs ≈ 20 × 10−6 is observed in as-prepared Fe47Ni27Si11B13C2, while low and negative λs ≈ −0.3 × 10−6 is obtained for Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 microwire. Annealing affects the magnetostriction coefficients and Curie temperatures, Tc, of both Fe47Ni27Si11B13C2 and Co67Fe3.9Ni1.5B11.5Si14.5Mo1.6 glass-coated microwires in a similar way. Observed dependencies of hysteresis loops, λs and Tc on annealing conditions are discussed in terms of superposition of internal stresses relaxation and structural relaxation of studied microwires. We observed linear λs dependence on applied stress, σ, in both studied microwires. A decrease in the magnetostriction coefficient upon applied stress is observed for Co-rich microwires with low and negative magnetostriction coefficient. On the contrary, for Fe-Ni-rich microwires with a positive magnetostriction coefficient, an increase in the magnetostriction coefficient with applied stress is observed. The observed results are discussed considering the internal stresses relaxation and short range atomic rearrangements induced by annealing on hysteresis loops, magnetostriction coefficients and Curie temperatures of studied microwires. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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14 pages, 3303 KiB  
Article
Influence of the Particle Size on the Electrical, Magnetic and Biological Properties of the Bioglass® Containing Iron Oxide
Magnetochemistry 2023, 9(9), 209; https://doi.org/10.3390/magnetochemistry9090209 - 12 Sep 2023
Viewed by 1040
Abstract
Bioglasses have been used throughout the past century as a biomaterial in the bone regeneration field. However, recent studies have attempted to use them as a therapeutic material as well, mainly in the treatment of osteosarcomas. The most widely recognized bioglass is the [...] Read more.
Bioglasses have been used throughout the past century as a biomaterial in the bone regeneration field. However, recent studies have attempted to use them as a therapeutic material as well, mainly in the treatment of osteosarcomas. The most widely recognized bioglass is the 45S5 Bioglass, invented by Larry Hench et al., which presents higher bioactivity. A possible application of this bioglass in the treatment of osteosarcomas can be accomplished by adding specific ions, such as iron, that will allow the use of magnetic hyperthermia and Fenton reaction as therapeutic mechanisms. In this study, a 45S5 Bioglass containing 10%mol of Fe2O3 was produced using the melt-quenching method. A group of samples was prepared by changing the overall ball milling time, from 1 h up to 48 h, to analyze the effects of iron in the bioactive glass matrix and evaluate the influence of particle size on their physical and biological properties. The studied bioglasses showed no evidence of changes in the amorphous structural nature compared to the 45S5 Bioglass. The data of the impedance spectroscopy study revealed that the addition of Fe2O3 can increase the standard rate constant of the Electro-Fenton reaction, with the sample milled for 12 h showing the most promising results. The reduction in the particle size influenced the cytotoxicity and the bioactivity. The samples with lower particle sizes showed a higher level of cytotoxicity. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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25 pages, 8960 KiB  
Article
NiFe Alloy Nanoparticles Tuning the Structure, Magnetism, and Application for Oxygen Evolution Reaction Catalysis
Magnetochemistry 2023, 9(8), 201; https://doi.org/10.3390/magnetochemistry9080201 - 08 Aug 2023
Cited by 2 | Viewed by 1457
Abstract
In this study, Ni-Fe alloy nanoparticles were prepared using the proteic sol–gel method, followed by a reduction in H2 at 500 and 700 °C, namely hereafter as NiFe-500 and NiFe-700, respectively. The morphological, structural, and magnetic properties were tuned via the thermal [...] Read more.
In this study, Ni-Fe alloy nanoparticles were prepared using the proteic sol–gel method, followed by a reduction in H2 at 500 and 700 °C, namely hereafter as NiFe-500 and NiFe-700, respectively. The morphological, structural, and magnetic properties were tuned via the thermal treatment in H2. The samples were studied using XPS, TEM, Mössbauer spectroscopy, DC magnetic measurements, and electrochemical measurements. Ritveld refinements showed that the sample NiFe-500 has FCC (face-centered cubic) and BCC (body-centered cubic) NiFe alloys, while the sample NiFe-700 has only FCC NiFe alloy. For both samples, magnetization measurements in the range of 300–900 K showed the presence of the Griffiths phase, indicating the formation of clusters of either Fe or Ni-Fe alloys rich in Fe. The sample NiFe-500 presented ferromagnetic (FM) transitions at 533, 700, and 834 K, assigned to the alloys Ni37Fe63-FCC, Ni46Fe54-FCC, and Ni55Fe45-FCC, respectively. In contrast, we could not observe the FM transition of the BCC Ni-Fe alloy because of limitations in our experimental setup (T ≤ 900 K). Meanwhile, three FM transitions were observed for the sample NiFe-700 at 480, 655, and 825 K, attributed to the alloys Ni34Fe66-FCC, Ni43Fe57-FCC, and Ni54Fe46-FCC, respectively. At 5 K, the samples NiFe-500 and NiFe-700 have saturation magnetizations of 164.2 and 173.6 emu g−1, respectively. For application in Oxygen Evolution Reaction catalysis, the samples NiFe-500 and NiFe-700 showed different overpotentials of 319 and 307 mV at 10 mA cm−2. These low overpotential values indicate a higher electrochemical activity of the FCC Ni-Fe alloy and, for both samples, a superior electrocatalytic activity in comparison to RuO2 e IrO2 conventional catalysts. Furthermore, the samples showed high electrochemical stability in chrono potentiometric studies for up to 15 h. This current work highlights that the Ni-Fe alloys produced via the proteic sol–gel and with a reduction in H2 methods can be promising for OER systems due to their good performance and low costs. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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16 pages, 5462 KiB  
Article
Magnetic and Magnetocaloric Properties of Nano- and Polycrystalline Bulk Manganites La0.7Ba(0.3−x)CaxMnO3 (x ≤ 0.25)
Magnetochemistry 2023, 9(7), 170; https://doi.org/10.3390/magnetochemistry9070170 - 30 Jun 2023
Viewed by 1069
Abstract
Here we report the synthesis and investigation of bulk and nano-sized La0.7Ba0.3−xCaxMnO3 (x = 0, 0.15, 0.2 and 0.25) compounds that are promising candidates for magnetic refrigeration applications. We compare the structural and magnetic properties of [...] Read more.
Here we report the synthesis and investigation of bulk and nano-sized La0.7Ba0.3−xCaxMnO3 (x = 0, 0.15, 0.2 and 0.25) compounds that are promising candidates for magnetic refrigeration applications. We compare the structural and magnetic properties of bulk and nano-scale polycrystalline La0.7Ba0.3−xCaxMnO3 for potential use in magnetic cooling systems. Solid-state reactions were implemented for bulk materials, while the sol–gel method was used for nano-sized particles. Structurally and morphologically, the samples were investigated by X-ray diffraction (XRD), optical microscopy and transmission electron microscopy (TEM). Oxygen stoichiometry was investigated by iodometry. Bulk compounds exhibit oxygen deficiency, while nano-sized particles show excess oxygen. Critical magnetic behavior was revealed for all samples using the modified Arrott plot (MAP) method and confirmed by the Kouvel–Fisher (KF) method. The bulk polycrystalline compound behavior was better described by the tricritical field model, while the nanocrystalline samples were governed by the mean-field model. Resistivity in bulk material showed a peak at a temperature Tp1 attributed to grain boundary conditions and at Tp2 associated with a Curie temperature of Tc. Parent polycrystalline sample La0.7Ba0.3MnO3 has Tc at 340 K. Substitution of x = 0.15 of Ca brings Tc to 308 K, and x = 0.2 brings it to 279 K. Nanocrystalline samples exhibit a very wide effective temperature range in the magnetocaloric effect, up to 100 K. Bulk compounds exhibit a high and sharp peak in magnetic entropy change, up to 7 J/kgK at 4 T at Tc for x = 0.25. To compare the magnetocaloric performances of the studied compounds, both relative cooling power (RCP) and temperature-averaged entropy change (TEC) figures of merit were used. RCP is comparable for bulk polycrystalline and nano-sized samples of the same substitution level, while TEC shows a large difference between the two systems. The combination of bulk and nanocrystalline materials can contribute to the effectiveness and improvement of magnetocaloric materials. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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12 pages, 3876 KiB  
Article
Structural and Magnetic Investigations of the Novel Pyrophosphate Na7Ni3Fe(P2O7)4
Magnetochemistry 2023, 9(7), 162; https://doi.org/10.3390/magnetochemistry9070162 - 24 Jun 2023
Viewed by 949
Abstract
A novel pyrophosphate Na7Ni3Fe(P2O7)4 was synthesized in two distinct forms, single-crystal and powder. Single-crystal X-ray diffraction was used to determine the crystal structure, and powder X-ray diffraction and scanning electron microscopy were used to [...] Read more.
A novel pyrophosphate Na7Ni3Fe(P2O7)4 was synthesized in two distinct forms, single-crystal and powder. Single-crystal X-ray diffraction was used to determine the crystal structure, and powder X-ray diffraction and scanning electron microscopy were used to examine the purity and morphology of the elaborated powder. This phosphate crystallizes in the P1¯ space group of the triclinic system with a = 6.3677 (2) Å, b = 9.3316 (4) Å, c = 10.8478 (4) Å, α = 65.191 (1)°, β = 80.533 (1)° and γ = 73.042 (1)°. The crystal framework is assembled from the linkage of centro-symmetrical clusters Ni2(Ni/Fe)2P4O28. Each cluster consists of two (Fe1/Ni1)O6 octahedra, two Ni2O6 octahedra and two P2O7 units. The linkage of these clusters is provided by two other P2O7 units to generate a three-dimensional structure with distinct tunnels in the [100], [010] and [001] directions, housing the Na+ cations. The infrared and Raman analyses show the characteristic bands of the pyrophosphate anion P2O74−. Remarkably, the magnetic investigations revealed the coexistence of two magnetic transitions at ~29 K and ~4.5 K with dominating antiferromagnetic interactions. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
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