Structural and magnetic study of the iron cores in iron(III)-polymaltose pharmaceutical ferritin analogue Ferrifol®

Iron(III)-polymaltose pharmaceutical ferritin analogue Ferrifol® was investigated by high resolution transmission electron microscopy (HRTEM), X-ray diffraction, thermogravimetry, electron magnetic resonance (EMR) spectroscopy, dc magnetization measurements and 57Fe Mössbauer spectroscopy to get novel information about the structural arrangement of the iron core. The Ferrifol® Mössbauer spectra measured in the range from 295 to 90 K demonstrated non-Lorentzian two-peak pattern. These spectra were better fitted using a superposition of 5 quadrupole doublets with the same line width. The obtained Mössbauer parameters were different and an unusual line broadening with temperature decrease was observed. Measurements of the Ferrifol® Mössbauer spectra from 60 to 20 K demonstrated a slow decrease of magnetic relaxation in the iron core. Zero-field-cooled and field-cooled magnetization measurements revealed a blocking temperature at ~33 K and paramagnetic state of the Ferrifol® iron core at higher temperatures. Isothermal magnetization measurements at 5 K show that the saturation magnetic moment is ~0.31 emu/g. X-band EMR spectroscopy measurements revealed the presence of different magnetic species in the sample. Transmission electron microscopy demonstrated that the size of the iron cores in Ferrifol® is in the range 2–6 nm. The lattice periodicity in these iron cores, measured on the HRTEM images, appeared to be vary in the range 2.2–2.7 Å. This can be best understood as sets of close packed O(OH) layers in ferrihydrite cores without long range correlation

Bjurböle L/LL4 ordinary chondrite properties studied by Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy

Bjurbole L/LL4 ordinary chondrite was studied using scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mossbauer spectroscopy. The phase composition and the relative iron fractions in the iron-bearing phases were determined. The unit cell parameters for olivine, orthopyroxene and clinopyroxene are similar to those observed in the other ordinary chondrites. The higher contents of forsterite and enstatite were detected by Raman spectroscopy. Magnetization measurements showed that the temperature of the ferrimagnetic-paramagnetic phase transition in chromite is around 57 K and the saturation magnetic moment is similar to 7 emu/g. The values of the Fe-57 hyperfine parameters for all components in the Bjurbole Mossbauer spectrum were determined and related to the corresponding iron-bearing phases. The relative iron fractions in Bjurbole and the Fe-57 hyperfine parameters of olivine, orthopyroxene and troilite were compared with the data obtained for the selected L and LL ordinary chondrites. The Fe2+ occupancies of the M1 and M2 sites in silicate crystals were determined using both X-ray diffraction and Mossbauer spectroscopy. Then, the temperatures of equilibrium cation distribution were determined, using two independent techniques, for olivine as 666 K and 850 K, respectively, and for orthopyroxene as 958 K and 1136 K, respectively. Implications of X-ray diffraction, magnetization measurements and Mossbauer spectroscopy data for the classification of the studied Bjurbole material indicate its composition being close to the LL group of ordinary chondrites. (C) 2020 Elsevier B.V. All rights reserved.Peer reviewe

Structural and Magnetic Study of the Iron Cores in Iron(III)-Polymaltose Pharmaceutical Ferritin Analogue Ferrifol®

Iron(III)-polymaltose pharmaceutical ferritin analogue Ferrifol® was investigated by high resolution transmission electron microscopy (HRTEM), X-ray diffraction, thermogravimetry, electron magnetic resonance (EMR) spectroscopy, direct current magnetization measurements and 57Fe Mössbauer spectroscopy to get novel information about the structural arrangement of the iron core. The Ferrifol® Mössbauer spectra measured in the range from 295 K to 90 K demonstrated non-Lorentzian two-peak pattern. These spectra were better fitted using a superposition of 5 quadrupole doublets with the same line width. The obtained Mössbauer parameters were different and an unusual line broadening with temperature decrease was observed. Measurements of the Ferrifol® Mössbauer spectra from 60 K to 20 K demonstrated a slow decrease of magnetic relaxation in the iron core. Zero-field-cooled and field-cooled magnetization measurements revealed a blocking temperature at ~33 K and a paramagnetic state of the Ferrifol® iron core at higher temperatures. Isothermal magnetization measurements at 5 K show that the saturation magnetic moment is ~0.31 emu/g. X-band EMR spectroscopy measurements revealed the presence of different magnetic species in the sample. Transmission electron microscopy demonstrated that the size of the iron cores in Ferrifol® is in the range 2–6 nm. The lattice periodicity in these iron cores, measured on the HRTEM images, vary in the range 2.2–2.7 Å. This can be best understood as sets of close packed O(OH) layers in ferrihydrite cores without long range correlation. © 2020 Elsevier Inc.The authors wish to thank Prof. Ferenc Simon (Institute of Physics, Budapest University of Technology and Economics, Budapest, Hungary) for making available the applied spectrometer for recording the EMR spectra and Dr. A.V. Chukin (Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russian Federation) for XRD measurements. This work was supported by the Ministry of Science and Higher Education of the Russian Federation, project No FEUZ-2020-0060, and Act 211 of the Government of the Russian Federation, contract No 02.A03.21.0006. V.K.K. was supported by the János Bolyai Postdoctoral Fellowship of the Hungarian Academy of Sciences and the ÚNKP-19-4 New National Excellence Program of the Ministry for Innovation and Technology. HRTEM facility at the Centre for Energy Research was granted by the European Structural and Investment Funds, grant no. VEKOP-2.3.3-15-2016-00002. This work was in part supported by the Hungarian National Research, Development and Innovation Office – NKFIH (K115784, K115913 and K134770). This work was carried out within the Agreement of Cooperation between the Ural Federal University (Ekaterinburg) and the Eötvös Loránd University (Budapest)

Mössbauer study of FINEMET with different permeability

Stress field and magnetic field annealed FINEMET ribbons were investigated by 57Fe Mössbauer spectroscopy, magnetic and XRD methods. The change in relative areas of the 2nd and 5th lines in the Mössbauer spectra indicated significant variation in magnetic anisotropy due to the different annealing. High velocity resolution Mössbauer spectroscopy was also used to control the model applied for the evaluation of Mössbauer spectra. A correlation was found between the permeability and the magnetic anisotropy of the annealed FINEMET samples. This can be applied to predict production parameters of FINEMET ribbons with more favorable soft magnetic properties for technological applications. © 2012 Springer Science+Business Media Dordrecht

Change in Magnetic Anisotropy at the Surface and in the Bulk of FINEMET Induced by Swift Heavy Ion Irradiation

57 Fe transmission and conversion electron Mössbauer spectroscopy as well as XRD were used to study the effect of swift heavy ion irradiation on stress-annealed FINEMET samples with a composition of Fe73.5 Si13.5 Nb3 B9 Cu1. The XRD of the samples indicated changes neither in the crystal structure nor in the texture of irradiated ribbons as compared to those of non-irradiated ones. However, changes in the magnetic anisotropy both in the bulk as well as at the surface of the FINEMET alloy ribbons irradiated by 160 MeV132 Xe ions with a fluence of 1013 ion cm−2 were revealed via the decrease in relative areas of the second and fifth lines of the magnetic sextets in the corresponding Mössbauer spectra. The irradiation-induced change in the magnetic anisotropy in the bulk was found to be similar or somewhat higher than that at the surface. The results are discussed in terms of the defects produced by irradiation and corresponding changes in the orientation of spins depending on the direction of the stress generated around these defects. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.CZ-11/2007, MEB040806; Ministry of Education and Science of the Russian Federation, Minobrnauka: FEUZ-2020-0060; Hungarian Scientific Research Fund, OTKA: K100424, K115784, K115913, K43687, K68135; Joint Institute for Nuclear Research, JINR; Univerzita Palackého v Olomouci: CZ.02.1.01/0.0/0.0/17_049/0008408, IGA_PrF_2022_003, IGA_PrF_2022_013; Ural Federal University, UrFU: 04-5-1131-2017/2021; Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIHFunding: The research was supported by grants from the Hungarian National Research, Development and Innovation Office (OTKA projects No K43687, K68135, K100424, K115913, K115784) and by the Czech-Hungarian Intergovernmental Fund, Grant No. CZ-11/2007 (MEB040806). M.I.O. was supported by the Ministry of Science and Higher Education of the Russian Federation, project No. FEUZ-2020-0060. Additionally, M.I.O. was supported in part by the Ural Federal University project within the Priority-2030 Program, funded from the Ministry of Science and Higher Education of the Russian Federation. This work was also supported by the project “Swift heavy ions in research of iron-bearing nanomaterials”, No. of theme 04-5-1131-2017/2021, solved in cooperation with the Czech Republic and the JINR (3 + 3 projects), and also by internal IGA grant of Palacký University (IGA_PrF_2022_003). The authors from Palacký University Olomouc want to thank the facilitators of project CZ.02.1.01/0.0/0.0/17_049/0008408 of the Ministry of Education, Youth & Sports of the Czech Republic for their support as well.Acknowledgments: We are grateful to Z. Klencsár (Centre for Energy Research, Budapest), M. Miglierini (Technical University, Bratislava), I. Dézsi (Wigner Research Centre for Physics, Budapest), S. Kubuki, and K. Nomura (Tokyo Metropolitan University, Tokyo) for their participation in discussions, and L. Krupa (Czech Technical University in Prague, Czech Republic and Joint Institute for Nuclear Research, Dubna) for his help with the organization of project cooperation. The support by grants from the Hungarian National Research, Development and Innovation Office and by the Czech-Hungarian Intergovernmental Fund, Grant No. CZ-11/2007 (MEB040806) are acknowledged. M.I.O. is grateful for support from the Ministry of Science and Higher Education of the Russian Federation and from the Ural Federal University project within the Priority-2030 Program. This work was also carried out within the Agreement of Cooperation between the Ural Federal University (Ekaterinburg) and the Eötvös Loránd University (Budapest) and within the Memorandum of Understanding between the Ural Federal University (Ekaterinburg) and the Palacký University (Olomouc). Authors acknowledge the support of the project “Swift heavy ions in research of iron-bearing nanomaterials”, No. of theme 04-5-1131-2017/2021, solved in cooperation with the Czech Republic and the JINR (3 + 3 projects). Authors from Palacký University Olomouc appreciate the internal IGA grant of Palacký University (IGA_PrF_2022_013) and thank the facilitators of the project CZ.02.1.01/0.0/0.0/17_049/0008408 of the Ministry of Education, Youth & Sports of the Czech Republic as well

Mössbauer spectroscopy of human liver ferritin and its analogue, Ferrum Lek, in the temperature range of 295-90 K: Comparison within the homogeneous iron core model

Human liver ferritin and its pharmaceutical analogue, Ferrum Lek, containing nanosized hydrous ferric oxides cores in the forms of ferrihydrite and akaganéite, respectively, were studied using Mössbauer spectroscopy with a high velocity resolution in the temperature range of 295-90 K. To simplify comparison, these spectra were fitted using one quadrupole doublet within the homogeneous iron core model. An unusual line broadening with a temperature decrease was observed in this way for human liver ferritin below ~ 150 K and for Ferrum Lek below ~ 130 K. Some anomalies were also observed below these temperatures for spectral area and quadrupole splitting. The Debye temperature for both iron cores was evaluated from temperature dependence of isomer shift using the temperature dependence of the second-order Doppler shift. © 2014 AIP Publishing LLC.11169