Pub Date : 2023-08-01DOI: 10.3390/magnetochemistry9080197
D. Kalyuzhnaya, Evgeniy Sokolov, A. Vasilyeva, Irina Sutarina, I. Shabanova, P. Ryapolov
The microfluidics of magnetic fluids is gaining popularity due to the possibility of the non-contact control of liquid composite systems using a magnetic field. The dynamics of non-magnetic droplets and gas bubbles in magnetic fluids were investigated for various configurations of magnetic fields, coatings, and channel geometries, as well as the rate of component supply and their physical properties. Optimal regimes for forming droplet and bubble flows were determined. The mechanism for non-contact control of the size of droplets and bubbles using a magnetic field is proposed in this article. The dependences of the sizes of non-magnetic inclusions in magnetic liquids on the continuous phase flow rate and the displacement of magnets were obtained. The obtained dependences of the volume of non-magnetic inclusions on the flow rate of the continuous phase follow the classic dependences. Changing the size of air bubbles can be achieved by shifting the magnet from −5 mm to +2 mm. The ratio of the maximum and minimum breakaway inclusion varies from 5 to 2 depending on the flow rates of the continuous phase. The range of changing the size of oil droplets with the displacement of magnets is from 1.1 to 1.51. These studies show how, with the help of various mechanisms of influence on microfluidic flows, it is possible to control the size of bubbles and droplets forming in microchannels. The obtained data can be applied for controlled microfluidic dosing and counting devices.
{"title":"Dynamics of Non-Magnetic Droplets and Bubbles in Magnetic Fluids in Microfluidic Channels under the Influence of a Magnetic Field","authors":"D. Kalyuzhnaya, Evgeniy Sokolov, A. Vasilyeva, Irina Sutarina, I. Shabanova, P. Ryapolov","doi":"10.3390/magnetochemistry9080197","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080197","url":null,"abstract":"The microfluidics of magnetic fluids is gaining popularity due to the possibility of the non-contact control of liquid composite systems using a magnetic field. The dynamics of non-magnetic droplets and gas bubbles in magnetic fluids were investigated for various configurations of magnetic fields, coatings, and channel geometries, as well as the rate of component supply and their physical properties. Optimal regimes for forming droplet and bubble flows were determined. The mechanism for non-contact control of the size of droplets and bubbles using a magnetic field is proposed in this article. The dependences of the sizes of non-magnetic inclusions in magnetic liquids on the continuous phase flow rate and the displacement of magnets were obtained. The obtained dependences of the volume of non-magnetic inclusions on the flow rate of the continuous phase follow the classic dependences. Changing the size of air bubbles can be achieved by shifting the magnet from −5 mm to +2 mm. The ratio of the maximum and minimum breakaway inclusion varies from 5 to 2 depending on the flow rates of the continuous phase. The range of changing the size of oil droplets with the displacement of magnets is from 1.1 to 1.51. These studies show how, with the help of various mechanisms of influence on microfluidic flows, it is possible to control the size of bubbles and droplets forming in microchannels. The obtained data can be applied for controlled microfluidic dosing and counting devices.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42114857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-31DOI: 10.3390/magnetochemistry9080196
A. Sedelnikova, Yuliya Poletaeva, V. Golyshev, A. Chubarov, E. Dmitrienko
Hybrid magnetic molecularly imprinted polymers (MMIPs) have the advantages of the technology of molecularly imprinted material and magnetic nanoparticles. The magnetic properties of MMIPs allow easy magnetic separation of various pollutants and analytes. A convenient and simple approach has been developed for the preparation of MMIPs based on polyamide (nylon-6) and magnetic nanoparticles. The polymer matrix was formed during the transition of nylon-6 from a dissolved state to a solid state in the presence of template molecules and Fe3O4 nanoparticles in the initial solution. Methylene blue (MB) was used as a model imprinted template molecule. The MMIPs exhibited a maximum adsorption amount of MB reached 110 µmol/g. The selectivity coefficients toward MB structural analogs were estimated to be 6.1 ± 0.6 and 2.1 ± 0.3 for 15 μM hydroxyethylphenazine and toluidine blue, which shows high MMIP selectivity. To prove the MMIPs’ specificity in MB recognition, magnetic nonimprinted polymers (MNIPs) were synthesized without the presence of a template molecule. MMIPs exhibited much higher specificity in comparison to MNIPs. To show the remarkable reusability of the MMIP sorbent, more than four MB absorption and release cycles were carried out, demonstrating almost the same extraction capacity step by step. We believe that the proposed molecular imprinting technology, shown in the MB magnetic separation example, will bring new advances in the area of MMIPs for various applications.
{"title":"Preparation of Magnetic Molecularly Imprinted Polymer for Methylene Blue Capture","authors":"A. Sedelnikova, Yuliya Poletaeva, V. Golyshev, A. Chubarov, E. Dmitrienko","doi":"10.3390/magnetochemistry9080196","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080196","url":null,"abstract":"Hybrid magnetic molecularly imprinted polymers (MMIPs) have the advantages of the technology of molecularly imprinted material and magnetic nanoparticles. The magnetic properties of MMIPs allow easy magnetic separation of various pollutants and analytes. A convenient and simple approach has been developed for the preparation of MMIPs based on polyamide (nylon-6) and magnetic nanoparticles. The polymer matrix was formed during the transition of nylon-6 from a dissolved state to a solid state in the presence of template molecules and Fe3O4 nanoparticles in the initial solution. Methylene blue (MB) was used as a model imprinted template molecule. The MMIPs exhibited a maximum adsorption amount of MB reached 110 µmol/g. The selectivity coefficients toward MB structural analogs were estimated to be 6.1 ± 0.6 and 2.1 ± 0.3 for 15 μM hydroxyethylphenazine and toluidine blue, which shows high MMIP selectivity. To prove the MMIPs’ specificity in MB recognition, magnetic nonimprinted polymers (MNIPs) were synthesized without the presence of a template molecule. MMIPs exhibited much higher specificity in comparison to MNIPs. To show the remarkable reusability of the MMIP sorbent, more than four MB absorption and release cycles were carried out, demonstrating almost the same extraction capacity step by step. We believe that the proposed molecular imprinting technology, shown in the MB magnetic separation example, will bring new advances in the area of MMIPs for various applications.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48431331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-29DOI: 10.3390/magnetochemistry9080194
N. N. Habibullayev, N. Naumov, A. Lavrov, N. Kuratieva, A. Aleksandrovsky, A. Oreshonkov, M. Molokeev, I. Palamarchuk, Ilya O. Yurev, Yuriy G. Denisenko, O. Andreev, Alena D. Zakharova
SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) compounds crystallize in the Pnma and Cmcm orthorhombic space group and belong to the Eu2CuS3 and KCuZrS3 structural type, respectively. According to a single-crystal XRD study, the SrTmCuSe3 unit cell parameters are a = 4.0631 (4), b = 13.4544 (14), c = 10.4430 (10) Å, and V = 570.88 (10) Å3. All the studied SrLnCuSe3 samples in the temperature range of 1.77–300 K demonstrate paramagnetic behavior without any features pointing to magnetic ordering. The measured Curie constants coincide with the values expected for Ln3+ ions with good accuracy, which confirms the stoichiometric composition of the samples and the non-magnetic state of the copper ions, Cu1+ (S = 0). The conducted optical absorption study showed that the polycrystalline SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) samples are semiconductors with a direct bandgap ranging from 2.14 eV to 2.31 eV. Two indirect bandgaps were revealed and explained by the presence of optical transitions to highly dispersive subbands in the conduction band. The compounds demonstrate two reversible phase transitions α⇆β, β⇆γ and an incongruent melting at 1606 K (Dy), 1584 K (Ho), 1634 K (Er), and 1620 K (Tm) associated with the formation of solid solutions of SrSe, Cu2-XSe, and Ln2Se3 binary compounds.
SrLnCuSe3 (Ln = Dy, Ho, Er, Tm)化合物在Pnma和Cmcm正交空间群中结晶，分别属于Eu2CuS3和KCuZrS3结构类型。通过单晶XRD研究，SrTmCuSe3的晶胞参数为a = 4.0631 (4)， b = 13.4544 (14)， c = 10.4430 (10) Å， V = 570.88 (10) Å3。在所研究的SrLnCuSe3样品在1.77 ~ 300 K温度范围内均表现出顺磁性行为，没有任何指向磁性有序的特征。测量的居里常数与Ln3+离子的居里常数吻合，准确度较高，证实了样品的化学计量成分和铜离子Cu1+ (S = 0)的非磁性态。光学吸收研究表明，多晶SrLnCuSe3 (Ln = Dy, Ho, Er, Tm)样品为半导体，直接带隙在2.14 ~ 2.31 eV之间。揭示了两个间接带隙，并通过在导带中存在到高色散子带的光学跃迁来解释。该化合物表现出两个可逆相变α - β， β - γ和在1606 K (Dy)， 1584 K (Ho)， 1634 K (Er)和1620 K (Tm)下的不一致熔化，与SrSe, Cu2-XSe和Ln2Se3二元化合物的固溶体形成有关。
{"title":"Magnetic, Optical, and Thermic Properties of SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) Compounds","authors":"N. N. Habibullayev, N. Naumov, A. Lavrov, N. Kuratieva, A. Aleksandrovsky, A. Oreshonkov, M. Molokeev, I. Palamarchuk, Ilya O. Yurev, Yuriy G. Denisenko, O. Andreev, Alena D. Zakharova","doi":"10.3390/magnetochemistry9080194","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080194","url":null,"abstract":"SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) compounds crystallize in the Pnma and Cmcm orthorhombic space group and belong to the Eu2CuS3 and KCuZrS3 structural type, respectively. According to a single-crystal XRD study, the SrTmCuSe3 unit cell parameters are a = 4.0631 (4), b = 13.4544 (14), c = 10.4430 (10) Å, and V = 570.88 (10) Å3. All the studied SrLnCuSe3 samples in the temperature range of 1.77–300 K demonstrate paramagnetic behavior without any features pointing to magnetic ordering. The measured Curie constants coincide with the values expected for Ln3+ ions with good accuracy, which confirms the stoichiometric composition of the samples and the non-magnetic state of the copper ions, Cu1+ (S = 0). The conducted optical absorption study showed that the polycrystalline SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) samples are semiconductors with a direct bandgap ranging from 2.14 eV to 2.31 eV. Two indirect bandgaps were revealed and explained by the presence of optical transitions to highly dispersive subbands in the conduction band. The compounds demonstrate two reversible phase transitions α⇆β, β⇆γ and an incongruent melting at 1606 K (Dy), 1584 K (Ho), 1634 K (Er), and 1620 K (Tm) associated with the formation of solid solutions of SrSe, Cu2-XSe, and Ln2Se3 binary compounds.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44032595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-29DOI: 10.3390/magnetochemistry9080195
D. H. Manh, T. Thi, N. T. N. Anh, V. H. Ky, Nguyen Manh Nghia, T. D. Thanh
Nanocomposites of polyaniline (PANI)/Fe2.85Ni0.15O4 (PFN) were successfully prepared using the co-precipitation method combined with an in-situ polymerization process. The FN and PFN nanocatalysts were characterized using various methods for the photocatalytic degradation of Rhodamine B (RhB). The XRD, Raman, TEM, and DTA-DTG analyses suggest that the FN nanoparticles (NPs) were effectively coated by PANI and that there were interactions between FN and PANI. Magnetic measurements indicated that PFN nanocomposites exhibited good superparamagnetic behavior and high saturation magnetization (39.5–57.6 emu/g), which are suitable for separating photocatalysts from solution for reuse. Adsorption-desorption analysis showed that the specific surface area of PFN was higher than that of FN. The UV-vis absorption spectra of FN and PFN nanocomposites exhibited strong absorption of visible light, attributed to the doping of Ni, which resulted in the reduction of the band-gap energy (Eg) of Fe3O4 to 2.4 eV. PFN nanocomposites with different mass ratios of PANI demonstrated superior photocatalytic activity compared to FN NPs. Furthermore, it was observed that PFN with a 10% mass ratio of PANI exhibited the highest RhB degradation efficiency, achieving a rate of approximately 98% after 300 min of irradiation. Finally, the possible photocatalytic degradation mechanisms of the PFN nanocomposites on RhB were discussed. PFN photocatalysts with good photocatalytic activity, inexpensive materials, and easy preparation could be potential candidates for wastewater purification applications.
{"title":"Facile Fabrication of PANI/Fe2.85Ni0.15O4 Nanocomposites and Their Application for the Effective Degradation of Rhodamine B Dye","authors":"D. H. Manh, T. Thi, N. T. N. Anh, V. H. Ky, Nguyen Manh Nghia, T. D. Thanh","doi":"10.3390/magnetochemistry9080195","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080195","url":null,"abstract":"Nanocomposites of polyaniline (PANI)/Fe2.85Ni0.15O4 (PFN) were successfully prepared using the co-precipitation method combined with an in-situ polymerization process. The FN and PFN nanocatalysts were characterized using various methods for the photocatalytic degradation of Rhodamine B (RhB). The XRD, Raman, TEM, and DTA-DTG analyses suggest that the FN nanoparticles (NPs) were effectively coated by PANI and that there were interactions between FN and PANI. Magnetic measurements indicated that PFN nanocomposites exhibited good superparamagnetic behavior and high saturation magnetization (39.5–57.6 emu/g), which are suitable for separating photocatalysts from solution for reuse. Adsorption-desorption analysis showed that the specific surface area of PFN was higher than that of FN. The UV-vis absorption spectra of FN and PFN nanocomposites exhibited strong absorption of visible light, attributed to the doping of Ni, which resulted in the reduction of the band-gap energy (Eg) of Fe3O4 to 2.4 eV. PFN nanocomposites with different mass ratios of PANI demonstrated superior photocatalytic activity compared to FN NPs. Furthermore, it was observed that PFN with a 10% mass ratio of PANI exhibited the highest RhB degradation efficiency, achieving a rate of approximately 98% after 300 min of irradiation. Finally, the possible photocatalytic degradation mechanisms of the PFN nanocomposites on RhB were discussed. PFN photocatalysts with good photocatalytic activity, inexpensive materials, and easy preparation could be potential candidates for wastewater purification applications.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45385246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-26DOI: 10.3390/magnetochemistry9080193
Jamil Kazmi, Jamal Kazmi, S. Raza, Babar Nazir, Raja Azhar Saeed Khan, M. A. Mohamed, M. Rafique
In this study, we grew pristine and Ni-doped vertically aligned zinc oxide nanowires (NWs) on a glass substrate. Both the doped and pristine NWs displayed dominant 002 peaks, confirming their vertical alignment. The Ni-doped NWs exhibited a leftward shift compared to the pristine NWs. TEM measurements confirmed the high crystallinity of individual NWs, with a d-spacing of ~0.267 nm along the c-axis. Ni-doped NWs had a higher density, indicating increased nucleation sites due to nickel doping. Doped NW films on glass showed enhanced absorbance in the visible region, suggesting the creation of sub-gap defect levels from nickel doping. Magnetization vs. magnetic field measurements revealed a small hysteresis loop, indicative of soft ferromagnetic behavior. Current transient plots demonstrated an increase in current with an applied magnetic field. Two-terminal devices exhibited a photo response that intensified with magnetic field application. This increase was attributed to parallel grain alignment, resulting in enhanced carrier concentration and photo response. In the dark, transport properties displayed negative magnetoresistance behavior. This magneto-transport effect and enhanced photo response (under an LED at ~395 nm) were attributed to giant magnetoresistance (GMR) in the aligned NWs. The observed behavior arose from reduced carrier scattering, improved transport properties, and parallel spin alignment in the magnetic field.
{"title":"Magneto-Transport and Enhanced Spin-Polarized Photo Response in Solution-Processed Vertically Aligned Zn0.9Ni0.1O Nanowires","authors":"Jamil Kazmi, Jamal Kazmi, S. Raza, Babar Nazir, Raja Azhar Saeed Khan, M. A. Mohamed, M. Rafique","doi":"10.3390/magnetochemistry9080193","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080193","url":null,"abstract":"In this study, we grew pristine and Ni-doped vertically aligned zinc oxide nanowires (NWs) on a glass substrate. Both the doped and pristine NWs displayed dominant 002 peaks, confirming their vertical alignment. The Ni-doped NWs exhibited a leftward shift compared to the pristine NWs. TEM measurements confirmed the high crystallinity of individual NWs, with a d-spacing of ~0.267 nm along the c-axis. Ni-doped NWs had a higher density, indicating increased nucleation sites due to nickel doping. Doped NW films on glass showed enhanced absorbance in the visible region, suggesting the creation of sub-gap defect levels from nickel doping. Magnetization vs. magnetic field measurements revealed a small hysteresis loop, indicative of soft ferromagnetic behavior. Current transient plots demonstrated an increase in current with an applied magnetic field. Two-terminal devices exhibited a photo response that intensified with magnetic field application. This increase was attributed to parallel grain alignment, resulting in enhanced carrier concentration and photo response. In the dark, transport properties displayed negative magnetoresistance behavior. This magneto-transport effect and enhanced photo response (under an LED at ~395 nm) were attributed to giant magnetoresistance (GMR) in the aligned NWs. The observed behavior arose from reduced carrier scattering, improved transport properties, and parallel spin alignment in the magnetic field.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47964985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-26DOI: 10.3390/magnetochemistry9080192
Hadeel Moustafa, F. H. Larsen, A. Madsen, S. Sauer
In this work we present a systematic, theoretical investigation of the 13C NMR chemical shifts for several mono-, di- and trisaccharides in the solid state. The chemical shifts have been calculated using density functional theory (DFT) together with the gauge including the projector augmented wave (GIPAW) method as implemented in the CASTEP program. We studied the changes in the 13C NMR chemical shifts in particular due to the formation of one or two glycosidic linkages and due to crystal water. The largest changes, up to 14 ppm, are observed between the mono- and disaccharides and typically for the glycosidic linkage atoms, but not in all cases. An analysis of the bond angles at the glycosidic linkage and the observed changes in chemical shifts displays no direct correlation between them. Somewhat smaller changes in the range of 2 to 5 ppm are observed when single crystal water molecules are close to some of the atoms. Relating the changes in the chemical shifts of the carbon atoms closest to the crystal water to the distance between them does, however, not lead to a simple relation between them.
{"title":"13C NMR Chemical Shifts of Saccharides in the Solid State: A Density Functional Theory Study","authors":"Hadeel Moustafa, F. H. Larsen, A. Madsen, S. Sauer","doi":"10.3390/magnetochemistry9080192","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080192","url":null,"abstract":"In this work we present a systematic, theoretical investigation of the 13C NMR chemical shifts for several mono-, di- and trisaccharides in the solid state. The chemical shifts have been calculated using density functional theory (DFT) together with the gauge including the projector augmented wave (GIPAW) method as implemented in the CASTEP program. We studied the changes in the 13C NMR chemical shifts in particular due to the formation of one or two glycosidic linkages and due to crystal water. The largest changes, up to 14 ppm, are observed between the mono- and disaccharides and typically for the glycosidic linkage atoms, but not in all cases. An analysis of the bond angles at the glycosidic linkage and the observed changes in chemical shifts displays no direct correlation between them. Somewhat smaller changes in the range of 2 to 5 ppm are observed when single crystal water molecules are close to some of the atoms. Relating the changes in the chemical shifts of the carbon atoms closest to the crystal water to the distance between them does, however, not lead to a simple relation between them.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44340013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-25DOI: 10.3390/magnetochemistry9080191
I. Benguettat-El Mokhtari, D. Schmool
This review article aims to provide a comprehensive overview of recent FMR studies on magnetic oxide nanoparticles and their potential applications. The use of the FMR technique is a powerful tool to study the magnetic properties of magnetic nanoparticles and can provide valuable information on their behavior. For this, we will start by discussing the purpose of these magnetic nanoparticles and their application in various fields, including biomedical applications, energy storage, and environmental remediation. We will then discuss the methods used to prepare magnetic nanoparticles and the theory behind FMR including the superparamagnetic effect. Additionally, we will present the most recent studies on FMR for magnetic oxide nanoparticles by highlighting the effect of temperature and doping on the magnetic properties of these nanoparticles.
{"title":"Ferromagnetic Resonance in Magnetic Oxide Nanoparticules: A Short Review of Theory and Experiment","authors":"I. Benguettat-El Mokhtari, D. Schmool","doi":"10.3390/magnetochemistry9080191","DOIUrl":"https://doi.org/10.3390/magnetochemistry9080191","url":null,"abstract":"This review article aims to provide a comprehensive overview of recent FMR studies on magnetic oxide nanoparticles and their potential applications. The use of the FMR technique is a powerful tool to study the magnetic properties of magnetic nanoparticles and can provide valuable information on their behavior. For this, we will start by discussing the purpose of these magnetic nanoparticles and their application in various fields, including biomedical applications, energy storage, and environmental remediation. We will then discuss the methods used to prepare magnetic nanoparticles and the theory behind FMR including the superparamagnetic effect. Additionally, we will present the most recent studies on FMR for magnetic oxide nanoparticles by highlighting the effect of temperature and doping on the magnetic properties of these nanoparticles.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45367738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-22DOI: 10.3390/magnetochemistry9070190
Fabio Manna, Mariangela Oggianu, N. Avarvari, M. L. Mercuri
Lanthanide metal–organic frameworks (Ln-MOFs) showing single-molecule magnet (SMM) properties are an ever-growing family of materials where the magnetic properties can be tuned by various interrelated parameters, such as the coordinated solvent, temperature, organic linkers, lanthanide ions and their coordination environment. An overview of the general synthetic methodologies to access MOFs/Ln-MOFs and the peculiarities and parameters to control and/or fine-tune their SMM behavior is herein presented. Additionally, diverse challenging strategies for inducing SMM/SIM behavior in an Ln-MOF are discussed, involving redox activity and chirality. Furthermore, intriguing physical phenomena such as the CISS effect and CPL are also highlighted.
{"title":"Lanthanide-Based Metal–Organic Frameworks with Single-Molecule Magnet Properties","authors":"Fabio Manna, Mariangela Oggianu, N. Avarvari, M. L. Mercuri","doi":"10.3390/magnetochemistry9070190","DOIUrl":"https://doi.org/10.3390/magnetochemistry9070190","url":null,"abstract":"Lanthanide metal–organic frameworks (Ln-MOFs) showing single-molecule magnet (SMM) properties are an ever-growing family of materials where the magnetic properties can be tuned by various interrelated parameters, such as the coordinated solvent, temperature, organic linkers, lanthanide ions and their coordination environment. An overview of the general synthetic methodologies to access MOFs/Ln-MOFs and the peculiarities and parameters to control and/or fine-tune their SMM behavior is herein presented. Additionally, diverse challenging strategies for inducing SMM/SIM behavior in an Ln-MOF are discussed, involving redox activity and chirality. Furthermore, intriguing physical phenomena such as the CISS effect and CPL are also highlighted.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43903563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.3390/magnetochemistry9070189
Susana Aberturas, J. Olazagoitia, M. A. García, Antonio Hernando
In the automobile sector, energy recovery and sustainability are becoming more and more important, and energy-harvesting suspension systems (EHSAs) have a lot of promise to improve vehicle efficiency. This investigation expands on prior work that investigated the viability of an EHSA that uses permanent magnets and amorphous core coils. The performance of the proposed system is demonstrated and enhanced in the current study through the development and optimization of a prototype. A thorough testing of the prototype is performed to determine design improvements for boosting the system’s overall performance and to quantify the recovered energy. In previous work, a method was proposed to find the dependence of the magnetic flux with the relative position between the primary and secondary elements to obtain the optimal position for the system. This method is applied to optimize the energy harvesting coil by testing different configurations in terms of the placement and type of amorphous or nonamorphous core inside the energy harvesting coil. This is a crucial area of attention in order to maximize energy recovery while solving the low-frequency problem that suspension systems have (on the order of 10 Hz).
{"title":"Enhanced Energy Recovery in Magnetic Energy-Harvesting Shock Absorbers Using Soft Magnetic Materials","authors":"Susana Aberturas, J. Olazagoitia, M. A. García, Antonio Hernando","doi":"10.3390/magnetochemistry9070189","DOIUrl":"https://doi.org/10.3390/magnetochemistry9070189","url":null,"abstract":"In the automobile sector, energy recovery and sustainability are becoming more and more important, and energy-harvesting suspension systems (EHSAs) have a lot of promise to improve vehicle efficiency. This investigation expands on prior work that investigated the viability of an EHSA that uses permanent magnets and amorphous core coils. The performance of the proposed system is demonstrated and enhanced in the current study through the development and optimization of a prototype. A thorough testing of the prototype is performed to determine design improvements for boosting the system’s overall performance and to quantify the recovered energy. In previous work, a method was proposed to find the dependence of the magnetic flux with the relative position between the primary and secondary elements to obtain the optimal position for the system. This method is applied to optimize the energy harvesting coil by testing different configurations in terms of the placement and type of amorphous or nonamorphous core inside the energy harvesting coil. This is a crucial area of attention in order to maximize energy recovery while solving the low-frequency problem that suspension systems have (on the order of 10 Hz).","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42958858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-19DOI: 10.3390/magnetochemistry9070188
K. Sarkar, M. Jordan, A. Kebede, Steve Kriske, Frank Wise, Dhananjay Kumar
The magnetocaloric effect (MCE) in iron (Fe) nanoparticles incorporated within a titanium nitride (TiN) thin-film matrix grown using pulsed laser deposition (PLD) is investigated in this study. The study demonstrates the ability to control the entropy change across the magnetic phase transition by varying the size of the Fe nanoparticles. The structural characterization carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and scanning transmission electron (TEM) showed that TiN films are (111) textured, while the Fe-particles are mostly spherical in shapes, are single-crystalline, and have a coherent structure with the surrounding TiN thin-film matrix. The TiN thin-film matrix was chosen as a spacer layer since it is nonmagnetic, is highly corrosion-resistive, and can serve as an excellent conduit for extracting heat due to its high thermal conductivity (11 W/m K). The magnetic properties of Fe–TiN systems were investigated using a superconducting quantum interference device (SQUID) magnetometer. In-plane magnetic fields were applied to record magnetization versus field (M–H) and magnetization versus temperature (M–T) curves. The results showed that the Fe–TiN heterostructure system exhibits a substantial isothermal entropy change (ΔS) over a wide temperature range, encompassing room temperature to the blocking temperature of the Fe nanoparticles. Using Maxwell’s relation and analyzing magnetization–temperature data under different magnetic fields, quantitative insights into the isothermal entropy change (ΔS) and magnetocaloric effect (MCE) were obtained for the Fe–TiN heterostructure system. The study points out a considerable negative change in ΔS that reaches up to 0.2 J/kg K at 0.2 T and 300 K for the samples with a nanoparticle size on the order of 7 nm. Comparative analysis revealed that Fe nanoparticle samples demonstrate higher refrigeration capacity (RC) in comparison to Fe thin-film multilayer samples, with the RC increasing as the Fe particle size decreases. These findings provide valuable insights into the potential application of Fe–TiN heterostructures in solid-state cooling technologies, highlighting their enhanced magnetocaloric properties.
{"title":"Enhanced Magnetic Cooling through Tailoring the Size-Dependent Magnetocaloric Effect of Iron Nanoparticles Embedded in Titanium Nitride Thin Films","authors":"K. Sarkar, M. Jordan, A. Kebede, Steve Kriske, Frank Wise, Dhananjay Kumar","doi":"10.3390/magnetochemistry9070188","DOIUrl":"https://doi.org/10.3390/magnetochemistry9070188","url":null,"abstract":"The magnetocaloric effect (MCE) in iron (Fe) nanoparticles incorporated within a titanium nitride (TiN) thin-film matrix grown using pulsed laser deposition (PLD) is investigated in this study. The study demonstrates the ability to control the entropy change across the magnetic phase transition by varying the size of the Fe nanoparticles. The structural characterization carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and scanning transmission electron (TEM) showed that TiN films are (111) textured, while the Fe-particles are mostly spherical in shapes, are single-crystalline, and have a coherent structure with the surrounding TiN thin-film matrix. The TiN thin-film matrix was chosen as a spacer layer since it is nonmagnetic, is highly corrosion-resistive, and can serve as an excellent conduit for extracting heat due to its high thermal conductivity (11 W/m K). The magnetic properties of Fe–TiN systems were investigated using a superconducting quantum interference device (SQUID) magnetometer. In-plane magnetic fields were applied to record magnetization versus field (M–H) and magnetization versus temperature (M–T) curves. The results showed that the Fe–TiN heterostructure system exhibits a substantial isothermal entropy change (ΔS) over a wide temperature range, encompassing room temperature to the blocking temperature of the Fe nanoparticles. Using Maxwell’s relation and analyzing magnetization–temperature data under different magnetic fields, quantitative insights into the isothermal entropy change (ΔS) and magnetocaloric effect (MCE) were obtained for the Fe–TiN heterostructure system. The study points out a considerable negative change in ΔS that reaches up to 0.2 J/kg K at 0.2 T and 300 K for the samples with a nanoparticle size on the order of 7 nm. Comparative analysis revealed that Fe nanoparticle samples demonstrate higher refrigeration capacity (RC) in comparison to Fe thin-film multilayer samples, with the RC increasing as the Fe particle size decreases. These findings provide valuable insights into the potential application of Fe–TiN heterostructures in solid-state cooling technologies, highlighting their enhanced magnetocaloric properties.","PeriodicalId":18194,"journal":{"name":"Magnetochemistry","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45668891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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