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Lachowicz D, Kmita A, Gajewska M, Trynkiewicz E, Przybylski M, Russek SE, Stupic KF, Woodrum DA, Gorny KR, Celinski ZJ, Hankiewicz JH. Aqueous Dispersion of Manganese-Zinc Ferrite Nanoparticles Protected by PEG as a T 2 MRI Temperature Contrast Agent. Int J Mol Sci 2023; 24:16458. [PMID: 38003646 PMCID: PMC10671015 DOI: 10.3390/ijms242216458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/03/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
Mixed manganese-zinc ferrite nanoparticles coated with PEG were studied for their potential usefulness in MRI thermometry as temperature-sensitive contrast agents. Particles in the form of an 8.5 nm core coated with a 3.5 nm layer of PEG were fabricated using a newly developed, one-step method. The composition of Mn0.48Zn0.46Fe2.06O4 was found to have a strong thermal dependence of magnetization in the temperature range between 5 and 50 °C. Nanoparticles suspended in an agar gel mimicking animal tissue and showing non-significant impact on cell viability in the biological test were studied with NMR and MRI over the same temperature range. For the concentration of 0.017 mg/mL of Fe, the spin-spin relaxation time T2 increased from 3.1 to 8.3 ms, while longitudinal relaxation time T1 shows a moderate decrease from 149.0 to 125.1 ms. A temperature map of the phantom exposed to the radial temperature gradient obtained by heating it with an 808 nm laser was calculated from T2 weighted spin-echo differential MR images. Analysis of temperature maps yields thermal/spatial resolution of 3.2 °C at the distance of 2.9 mm. The experimental relaxation rate R2 data of water protons were compared with those obtained from calculations using a theoretical model incorporating the motion averaging regime.
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Affiliation(s)
- Dorota Lachowicz
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Krakow, Poland; (D.L.); (M.G.); (E.T.); (M.P.)
| | - Angelika Kmita
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Krakow, Poland; (D.L.); (M.G.); (E.T.); (M.P.)
| | - Marta Gajewska
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Krakow, Poland; (D.L.); (M.G.); (E.T.); (M.P.)
| | - Elżbieta Trynkiewicz
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Krakow, Poland; (D.L.); (M.G.); (E.T.); (M.P.)
| | - Marek Przybylski
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Krakow, Poland; (D.L.); (M.G.); (E.T.); (M.P.)
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, 30-059 Krakow, Poland
| | - Stephen E. Russek
- National Institute of Standards and Technology, 325 Broadway St, Boulder, CO 80305, USA; (S.E.R.)
| | - Karl F. Stupic
- National Institute of Standards and Technology, 325 Broadway St, Boulder, CO 80305, USA; (S.E.R.)
| | - David A. Woodrum
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA; (D.A.W.); (K.R.G.)
| | - Krzysztof R. Gorny
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA; (D.A.W.); (K.R.G.)
| | - Zbigniew J. Celinski
- Center for the BioFrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918, USA; (Z.J.C.); (J.H.H.)
| | - Janusz H. Hankiewicz
- Center for the BioFrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918, USA; (Z.J.C.); (J.H.H.)
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Stroud J, Hao Y, Read TS, Hankiewicz JH, Bilski P, Klodowski K, Brown JM, Rogers K, Stoll J, Camley RE, Celinski Z, Przybylski M. Magnetic particle based MRI thermometry at 0.2 T and 3 T. Magn Reson Imaging 2023; 100:43-54. [PMID: 36933774 DOI: 10.1016/j.mri.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/28/2023] [Accepted: 03/12/2023] [Indexed: 03/18/2023]
Abstract
This study provides insight into the advantages and disadvantages of using ferrite particles embedded in agar gel phantoms as MRI temperature indicators for low-magnetic field scanners. We compare the temperature-dependent intensity of MR images at low-field (0.2 T) to those at high-field (3.0 T). Due to a shorter T1 relaxation time at low-fields, MRI scanners operating at 0.2 T can use shorter repetition times and achieve a significant T2⁎ weighting, resulting in strong temperature-dependent changes of MR image brightness in short acquisition times. Although the signal-to-noise ratio for MR images at 0.2 T MR is much lower than at 3.0 T, it is sufficient to achieve a temperature measurement uncertainty of about ±1.0 °C at 37 °C for a 90 μg/mL concentration of magnetic particles.
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Affiliation(s)
- John Stroud
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Yu Hao
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Tim S Read
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Janusz H Hankiewicz
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Pawel Bilski
- Department of Physics, A. Mickiewicz University, Uniwersytetu Poznanskiego St. 2, 61-614 Poznan, Poland
| | - Krzysztof Klodowski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland
| | - Jared M Brown
- Colorado Center for Nanomedicine and Nanosafety, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Keegan Rogers
- Colorado Center for Nanomedicine and Nanosafety, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Josh Stoll
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Robert E Camley
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Zbigniew Celinski
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States; Department of Physics and Energy Science, University of Colorado, Colorado Springs 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918, United States
| | - Marek Przybylski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland; Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza Ave. 30, 30-059 Kraków, Poland.
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Konwar K, Sharma N, Pranjali P, Guleria A, Kaushik SD, Dutta A, Mukhopadhyay R, Sen D, Gao W, Deb P. Structure-Correlated Magnetic Resonance Transverse Relaxivity Enhancement in Superparamagnetic Ensembles with Complex Anisotropy Landscape. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11087-11098. [PMID: 36041119 DOI: 10.1021/acs.langmuir.2c01764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The aim of the work is to explore structure-relaxivity relationship by observing transverse relaxivity enhancement in magnetic resonance imaging (MRI) of differently organized superparamagnetic complex ensembles of zinc ferrite isotropic/anisotropic nanosystems. We observe that superparamagnetic systems show a correlation of MRI-transverse relaxivity, r2/r1, with spatial arrangement of nanoparticles, as well as magnetic easy axes and thermal-energy-dependent anisotropy energy landscape. The presence of highly random/partially aligned easy axes with enhanced anisotropy constant leads to modulation in transverse relaxation. As a result, we achieve highest contrast efficiency in compact ensemble of isotropic nanoparticles and hollow core ensemble. Indeed, core-shell ensemble with combined effect of aligned and randomly oriented easy magnetic axes shows a reduction in MRI contrast efficiency. However, we address a hypothesis for transverse contrast efficiency where we depict the correlation among MRI-transverse contrast efficiency with structural complexity of ensembles, differently arranged primary nanoparticles/magnetic easy axes, anisotropy constant, and collective magnetic behavior. In consequence, we simplify the limitation of quantum mechanical outer-sphere diffusion model of magnetic resonance relaxivity by neglecting the contribution of magnetization and introducing an anisotropy constant contribution with complex structure landscape of easy axes.
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Affiliation(s)
- Korobi Konwar
- Department of Physics, Tezpur University (Central University), Tezpur-784028, India
| | - Niyorjyoti Sharma
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Pranjali Pranjali
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow 226014, India
| | - Anupam Guleria
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow 226014, India
| | - Som Datta Kaushik
- UGC-DAE Consortium for Scientific Research, Mumbai Centre, R-5 Shed, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Anupam Dutta
- Department of Molecular Biology and Biotechnology, Tezpur University (Central University), Tezpur-784028, India
| | - Rupak Mukhopadhyay
- Department of Molecular Biology and Biotechnology, Tezpur University (Central University), Tezpur-784028, India
| | - Debasis Sen
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Pritam Deb
- Department of Physics, Tezpur University (Central University), Tezpur-784028, India
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Lachowicz D, Stroud J, Hankiewicz JH, Gassen R, Kmita A, Stepień J, Celinski Z, Sikora M, Zukrowski J, Gajewska M, Przybylski M. One-Step Preparation of Highly Stable Copper-Zinc Ferrite Nanoparticles in Water Suitable for MRI Thermometry. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2022; 34:4001-4018. [PMID: 35573108 PMCID: PMC9097161 DOI: 10.1021/acs.chemmater.2c00079] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/01/2022] [Indexed: 05/03/2023]
Abstract
Superparamagnetic ferrite nanoparticles coated with a polymer layer are widely used for biomedical applications. The objective of this work is to design nanoparticles as a magnetic resonance imaging (MRI) temperature-sensitive contrast agent. Copper-zinc ferrite nanoparticles coated with a poly(ethylene glycol) (PEG) layer are synthesized using a one-step thermal decomposition method in a polymer matrix. The resulting nanoparticles are stable in water and biocompatible. Using Mössbauer spectroscopy and magnetometry, it was determined that the grown nanoparticles exhibit superparamagnetic properties. Embedding these particles into an agarose gel resulted in significant modification of water proton relaxation times T 1, T 2, and T 2* determined by nuclear magnetic resonance measurements. The results of the spin-echo T 2-weighted MR images of an aqueous phantom with embedded Cu0.08Zn0.54Fe2.38O4 nanoparticles in the presence of a strong temperature gradient show a strong correlation between the temperature and the image intensity. The presented results support the hypothesis that CuZn ferrite nanoparticles can be used as a contrast agent for MRI thermometry.
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Affiliation(s)
- Dorota Lachowicz
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - John Stroud
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Janusz H. Hankiewicz
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - River Gassen
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Angelika Kmita
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Joanna Stepień
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Zbigniew Celinski
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Marcin Sikora
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Jan Zukrowski
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Marta Gajewska
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Marek Przybylski
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
- Faculty
of Physics and Applied Computer Science, AGH University of Science
and Technology, 30-059 Krakow, Poland
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Jens Groebner
- Department of Electrical Engineering and Information Technology South Westphalian University of Applied Sciences Bahnhofsallee 5 58507 Luedenscheid Germany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbH Aviares Research Network Deichstraße 25 20459 Hamburg Germany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
| | - Rainer Herges
- Otto Diels Institute of Organic Chemistry Christian Albrechts University Otto Hahn Platz 4 24118 Kiel Germany
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6
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Wellm V, Groebner J, Heitmann G, Sönnichsen FD, Herges R. Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging. Angew Chem Int Ed Engl 2021; 60:8220-8226. [PMID: 33606332 PMCID: PMC8048480 DOI: 10.1002/anie.202015851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Indexed: 12/27/2022]
Abstract
Temperature can be used as clinical marker for tissue metabolism and the detection of inflammations or tumors. The use of magnetic resonance imaging (MRI) for monitoring physiological parameters like the temperature noninvasively is steadily increasing. In this study, we present a proof-of-principle study of MRI contrast agents (CA) for absolute and concentration independent temperature imaging. These CAs are based on azoimidazole substituted NiII porphyrins, which can undergo Light-Driven Coordination-Induced Spin State Switching (LD-CISSS) in solution. Monitoring the fast first order kinetic of back isomerisation (cis to trans) with standard clinical MR imaging sequences allows the determination of half-lives, that can be directly translated into absolute temperatures. Different temperature responsive CAs were successfully tested as prototypes in methanol-based gels and created temperature maps of gradient phantoms with high spatial resolution (0.13×0.13×1.1 mm) and low temperature errors (<0.22 °C). The method is sufficiently fast to record the temperature flow from a heat source as a film.
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Affiliation(s)
- Vanessa Wellm
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Jens Groebner
- Department of Electrical Engineering and Information TechnologySouth Westphalian University of Applied SciencesBahnhofsallee 558507LuedenscheidGermany
| | - Gernot Heitmann
- IWS Innovations- und Wissenstrategien GmbHAviares Research NetworkDeichstraße 2520459HamburgGermany
| | - Frank D. Sönnichsen
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
| | - Rainer Herges
- Otto Diels Institute of Organic ChemistryChristian Albrechts UniversityOtto Hahn Platz 424118KielGermany
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Zhang Y, Guo S, Zhang P, Zhong J, Liu W. Iron oxide magnetic nanoparticles based low-field MR thermometry. NANOTECHNOLOGY 2020; 31:345101. [PMID: 32408274 DOI: 10.1088/1361-6528/ab932b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This paper reports on a highly accurate approach of magnetic resonance (MR) thermometry using iron oxide magnetic nanoparticles (MNPs) as temperature sensors. An empirical model for the description of the temperature dependent R 2 relaxation rate is proposed by taking into account the temperature sensitivity of the MNP magnetization. The temperature sensitivity of the MNP magnetization (η) and the temperature sensitivity of the R 2 relaxation rate (κ) are simulated with the proposed empirical models to investigate their dependence on the magnetic field and the particle size. Simulation results show the existence of optimal magnetic fields Hoη and Hoκ that maximize the temperature sensitivities η and κ. Furthermore, simulations and experiments demonstrate that the optimal magnetic field Hoη (Hoκ ) decreases with increasing the particle size. Experiments on temperature dependent R 2 relaxation rate are performed at different magnetic fields for MNP samples with different iron concentrations. Experimental results show that the proposed MR thermometry using MNPs as temperature sensors allows a temperature estimation accuracy of about 0.05 °C. We believe that the achieved approach of highly accurate MR thermometry is of great interest and significance to biomedicine and biology.
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Affiliation(s)
- Yapeng Zhang
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. Key Laboratory of Image Processing and Intelligent Control (Huazhong University of Science and Technology), Ministry of Education, Wuhan 430074, People's Republic of China
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Pham TN, Huy TQ, Le AT. Spinel ferrite (AFe2O4)-based heterostructured designs for lithium-ion battery, environmental monitoring, and biomedical applications. RSC Adv 2020; 10:31622-31661. [PMID: 35520663 PMCID: PMC9056412 DOI: 10.1039/d0ra05133k] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/06/2020] [Indexed: 12/17/2022] Open
Abstract
The development of spinel ferrite nanomaterial (SFN)-based hybrid architectures has become more popular owing to the fascinating physicochemical properties of SFNs, such as their good electro-optical and catalytic properties, high chemothermal stability, ease of functionalization, and superparamagnetic behaviour. Furthermore, achieving the perfect combination of SFNs and different nanomaterials has promised to open up many unique synergistic effects and advantages. Inspired by the above-mentioned noteworthy properties, numerous and varied applications have been recently developed, such as energy storage in lithium-ion batteries, environmental pollutant monitoring, and, especially, biomedical applications. In this review, recent development efforts relating to SFN-based hybrid designs are described in detail and logically, classified according to 4 major hybrid structures: SFNs/carbonaceous nanomaterials; SFNs/metal–metal oxides; SFNs/MS2; and SFNs/other materials. The underlying advantages of the additional interactions and combinations of effects, compared to the standalone components, and the potential uses have been analyzed and assessed for each hybrid structure in relation to lithium-ion battery, environmental, and biomedical applications. We have summarized recent developments in SFN-based hybrid designs. The additional interactions, combination effects, and important changes have been analyzed and assessed for LIB, environmental monitoring, and biomedical applications.![]()
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Affiliation(s)
- Tuyet Nhung Pham
- Phenikaa University Nano Institute (PHENA)
- Phenikaa University
- Hanoi 12116
- Vietnam
| | - Tran Quang Huy
- Phenikaa University Nano Institute (PHENA)
- Phenikaa University
- Hanoi 12116
- Vietnam
- Faculty of Electric and Electronics
| | - Anh-Tuan Le
- Phenikaa University Nano Institute (PHENA)
- Phenikaa University
- Hanoi 12116
- Vietnam
- Faculty of Materials Science and Engineering
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Bodnaruk AV, Kalita VM, Kulyk MM, Ryabchenko SM, Tovstolytkin AI, Solopan SO, Belous AG. Critical behavior of ensembles of superparamagnetic nanoparticles with dispersions of magnetic parameters. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:375801. [PMID: 31163402 DOI: 10.1088/1361-648x/ab26fa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Different processes governing magnetic properties of an ensemble of magnetic nanoparticles in the temperature region close to a transition from superparamagnetic to paramagnetic state are analyzed and the ways to separate them are suggested. Enhanced role of paraprocess in magnetization behavior near Curie temperature is stressed. A procedure to isolate paraprocess contribution and adequately determine spontaneous magnetization of the ensemble of superparamagnetic nanoparticles is proposed. Critical behavior of the spontaneous magnetization is experimentally determined for the ensemble of nanoparticles of lanthanum-strontium manganites, which are considered as promising materials for self-controlled magnetic nanohyperthermia. Effect of dispersion of magnetic parameters on effective magnetic characteristics of nanoparticles and their critical behavior is discussed. Theoretical background for the use of the 'effective Curie temperature for the ensemble of nanoparticles' concept is proposed for ensembles of particles with dispersion of their Curie temperature. Based on the results obtained, various strategies to develop novel biomedical applications, in particular those suitable for noninvasive temperature monitoring, are discussed.
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Affiliation(s)
- A V Bodnaruk
- Institute of Physics of the NAS of Ukraine, 46 Nauky Ave., Kyiv 03028, Ukraine
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