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 Showing 1 - 37 of 37 Journals sorted alphabetically Atom Indonesia Bulletin of the Atomic Scientists       (Followers: 8) CNL Nuclear Review Eksplorium : Buletin Pusat Pengembangan Bahan Galian Nuklir EPJ Nuclear Sciences & Technologies       (Followers: 3) Fusion Science and Technology       (Followers: 4) Ganendra : Majalah IPTEK Nuklir Hyperfine Interactions       (Followers: 1) IEEE Transactions on Sustainable Energy       (Followers: 13) International Journal of Advanced Nuclear Reactor Design and Technology International Journal of Critical Infrastructure Protection       (Followers: 4) International Journal of Nuclear Energy Science and Engineering       (Followers: 5) International Journal of Nuclear Law       (Followers: 3) International Journal of Nuclear Safety and Security       (Followers: 1) International Journal of Nuclear Security       (Followers: 1) Journal of Nuclear Energy Science & Power Generation Technology       (Followers: 2) Journal of Nuclear Engineering & Technology       (Followers: 3) Journal of Nuclear Science and Technology       (Followers: 2) Journal of Power Technologies       (Followers: 6) Journal of Radiation Research       (Followers: 3) Journal of the Physical Society of Japan       (Followers: 2) Kerntechnik Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology       (Followers: 1) Nano Energy       (Followers: 11) Nanomaterials and Energy       (Followers: 1) Nuclear Energy and Technology       (Followers: 3) Nuclear Engineering and Technology       (Followers: 5) Nuclear Materials and Energy       (Followers: 1) Nuclear Science and Engineering       (Followers: 7) Nuclear Science and Techniques Nuclear Technology       (Followers: 5) Nucleus Nukleonika Radiation Detection Technology and Methods       (Followers: 1) Tri Dasa Mega : Jurnal Teknologi Reaktor Nuklir Urania Jurnal Ilmiah Daur Bahan Bakar Nuklir World Journal of Nuclear Science and Technology       (Followers: 4)
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 Hyperfine InteractionsJournal Prestige (SJR): 0.368 Citation Impact (citeScore): 1Number of Followers: 1      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1572-9540 - ISSN (Online) 0304-3843 Published by Springer-Verlag  [2467 journals]
• Energy domain synchrotron-radiation-based Mössbauer spectroscopy of EuH2
under a few GPa pressure

Abstract: Abstract The pressure dependence of the 151Eu isomer shift of EuH2 in the Pnma structure was evaluated under the pressure below 5 GPa by 151Eu energy-domain synchrotron-radiation-based Mössbauer spectroscopy. The isomer shift gradually increased as the pressure increased and its pressure dependence was understood by the simple linear relation with the inverse of the lattice volume of the hydrides. Furthermore, the isomer shifts of Eu hydride under hydrogen pressure and those of EuH2 under helium pressure did not show systematic difference. These results suggested that there was no or little hydrogen absorption after the synthesis of Pnma EuH2 in the pressure range up to 5 GPa. The linear relation between the isomer shift and the inverse of the volume in this initial hydride phase would be applied to the 151Eu Mössbauer study on other Eu hydride phases under higher hydrogen pressure to estimate the presence or absence of additional hydrogen absorption.
PubDate: 2023-01-05

• Retraction Note: Characterization of nanosized metallic interfaces

PubDate: 2022-12-27

• Structural, Mössbauer and magnetic study of Co1-xZnxFe2O4
(x = 0.0 − 0.56) nano ferrites

Abstract: Abstract We report on the synthesis of spinel Co1-xZnxFe2O4 (x=0.0-0.56) ferrites by sol-gel auto-combustion method. X-ray diffraction ‘XRD’, magnetic measurements were used to study compositional-dependence of structural, magnetic properties, connection among them. Mössbauer spectroscopy was used to identify non-magnetic-phase, its effect on magnetic properties. Single-phased nano spinel-ferrite formation is confirmed by XRD. Increasing Zn-content leads to structural modifications such as decrease of lattice parameter, grain diameter DW-H, alteration of inversion parameter, disorder, tensile-strain, dislocation density, variation of A–O–B, A–O–A, B–O–B super-exchange-interaction and canting angles. Cationic distribution suggests that Fe3+,Co2+ ions reside on both A, B-sites, and with increasing Zn-content, B-site population of Fe3+, Zn2+ ions increases; while that of Co2+ ions decreases. Saturation magnetization shows noticeable dependence on canting angle suggests that the magnetization in the studied samples is described by Yafet-Kittel three-sub-lattice model. Coercivity Hc values are consistent with anisotropy, and its dependence on DW-H suggests that the studied samples are inoverlap-region between multiple-domains/single-domain. Reduced-remanence indicate the variation of inter-grain magnetostatic-interaction, isotropic-behavior of multi-domain particles. Observed broad peaks in magnetization derivative with field suggest large-number of dislocations, more-uniform particle-size. Switching-field-distribution proposes potential application of the studied x=0.0 sample in high density recording, and sample with x=0.56 in targeted drug delivery. Mössbauer measurements confirm three-magnetic-components corresponding to A,B-sites, Fe3+ ions in grain boundaries/surface, Fe has 3+ oxidation state, and growing paramagnetic-doublet, alone does not explain the trend of Ms, suggesting that it is a collective-effect of structural-modification, presence of paramagnetic-doublet.
PubDate: 2022-12-24

• CrIII-doped vanadate glass: characterization and application as a cathode
active material for lithium-ion batteries

Abstract: Abstract Lithium iron phosphovanadate glasses containing CrIII were obtained by the melt-quench method and applied as cathode active materials in lithium-ion batteries. Amorphous glass structures were produced with compositions of 15Li2O·10Fe2O3·5P2O5·xCr2O3·(70-x)V2O5 and 15Li2O·(10-x)Fe2O3·5P2O5·xCr2O3·70V2O5, where x varied from 0 to 5. Glass ceramic samples were prepared by annealing at 500 °C for 90 min. 57Fe-Mössbauer spectra of 15Li2O‧10Fe2O3‧5P2O5‧70V2O5 glass measured at room temperature before and after the annealing proved that some iron (III) atoms changed the structural role from distorted “octahedral” NWM sites to distorted “tetrahedral” NWF sites. High capacities of 250–300 mA‧h− 1 were achieved during discharge from 4.2 to 2.0 V. The substitution of V with CrIII was shown to have a considerable positive effect on the electrochemical performance of the glass material.
PubDate: 2022-12-23

• Correction to: Absence of ferromagnetic behaviour in Mn implanted ZnO

PubDate: 2022-12-22

• How Mössbauer spectroscopy can be of value to industry to select
extraterrestrial objects for natural resources

Abstract: Abstract Space agencies are working on the project of capturing asteroids which contain natural resources valuable for industry. Based on studies of meteorites samples it was determined that the most useful source of raw materials for this purpose could be parent bodies of ordinary chondrites of type H. The identification of the type of ordinary chondrites with the use of a classical method (determination of the Fa/Fs ratio (fayalite versus ferrosilite) by electron microprobe measurements) cannot be performed on the surface of asteroids due to technical reasons. It may, however, be done based on Mössbauer measurements followed by the application of the 4M method. The name of the method – 4M, comes from four words: Meteorites, Mössbauer spectroscopy, Multidimensional discriminant analysis and Mahalanobis distance. Following the success of Mössbauer spectroscopy in the mission on Mars, there are suggestions to use the same method for the investigation of the surface of asteroids. In our experimental study, in which five Mössbauer laboratories took part, we assessed the effectiveness and reliability of the 4M method by comparison of the results obtained by Mössbauer studies of ordinary chondrites of type H, L and LL. Details of the study and problems related to the effectiveness of the 4M method are discussed.
PubDate: 2022-12-20

• Mössbauer studies of core-single-shell and core-double-shell polymer
functionalized magnetic nanoparticles

Abstract: Abstract Two different magnetic core–shell nanohybrids, i) single coated magnetic nanoparticles (NPs) with polyacrylonitrile (PAN) and ii) doubly coated with SiO2 and polyaniline (PANI), were synthesized by a modified chemical co-precipitation method and their structural, vibrational, colloidal, and magnetic properties were systematically studied. XRD and Rietveld refinement have shown the coexistence of 7.4(1) nm γ-Fe2O3 NPs, amorphous silica, and the polymeric chains of PANI for the core-double-shell nanohybrid, i.e., γ-Fe2O3@SiO2@PANI NPs. The γ-Fe2O3 NPs in this nanohybrid had reduced their sizes when compared to bare γ-Fe2O3 NPs or to γ-Fe2O3 NPs in the γ-Fe2O3@PAN nanohybrid. In addition, it has a controlled surface charge potential, i.e., it has been changed from positive in bare γ-Fe2O3/NPs to negative in γ-Fe2O3/PAN NPs (or in γ-Fe2O3@SiO2 NPs). Raman and Infrared studies have also confirmed the surface functionalization. 57Fe Mössbauer spectra of the 7.4(1) nm γ-Fe2O3@SiO2@PANI NPs revealed superparamagnetic fluctuations above 150 K, suggesting that the coating with PANI has inhibited particle agglomeration and reduced interparticle magnetic interactions. In contrast, 57Fe Mössbauer spectra of the γ-Fe2O3/PAN NPs displayed static sextets, as commonly found in NPs bigger than 10 nm. Considering the small particle sizes (< 10 nm), the NP controlled surface charge potential and the good magnetic properties, it can be inferred that these nanohybrids are suitable for magnetic remediation processes.
PubDate: 2022-12-19

• Mössbauer study of the material of the electric power transformers

Abstract: Abstract Fe-Si alloy is a soft magnetic material used as the core of electric power transformers. One method of molding the core is to press the powdered alloy into the shape of the core. In our study, the X-ray diffraction measurements performed on this processed material, we observed that the peak intensity of ordered phase Fe3Si was decreased in the pressed sample. The amount of ordered phase is important for the magnetic material. We performed 57Fe Mössbauer spectroscopy to elucidate this decrease in the ordered phase. The obtained Mössbauer spectra do not show change with or without pressing. This result indicates that the amount of the ordered phase does not decrease in atomic micro-environments upon pressing. The decrease of the peak intensity in X-ray diffraction can be associated with the distortion or deformation of the ordered phase particles. This consideration is also consistent with the FWHM of the Mössbauer spectrum being slightly broadened on the pressed sample.
PubDate: 2022-12-08

• Absence of ferromagnetic behaviour in mn implanted ZnO

Abstract: Abstract Application of ZnO as a dilute magnetic semiconductor awaits consensus on the source of reported ferromagnetic behaviour in doped ZnO, whether due to dopant-defect interactions or formation of nanoclusters of the magnetic ion dopants. In a contribution to this search, we report on conversion electron Mössbauer Spectroscopy (CEMS) and magnetization studies on single crystal ZnO substrates implanted with Mn ions with energies and fluences designed to give flat implantation profiles with 3 and 7 at% concentration (samples ZnO:Mn1 and ZnO:Mn2). For CEMS measurements, the substrates were also co-implanted with 3.9 × 1015 cm-2, 60 keV 57Fe ions. The CEM spectra of both samples, after annealing at 600oC, and above, show no evidence of ferromagnetic components but are dominated by paramagnetic doublets with isomer shifts consistent with Fe3+. The primary doublet component for both samples have identical values of isomer shifts and quadrupole splittings, thus reflecting the similarity in size and nature of the clusters formed. Magnetic isotherms on the ZnO:Mn1 doped sample are satisfactorily fitted by the Langevin function in the range 5 K < T < 30 K, where the magnetic units are isolated Mn, Fe and defect sites and the system is superparamagnetic. At T = 294 K, a fit to the Langevin fit indicates precipitates/clusters of nano-size dimensions in range where superparamagnetic behaviour is expected.
PubDate: 2022-12-03

• In-Field 57Fe Mössbauer study of maghemite nanoparticles functionalized
multiwall carbon nanotubes and their ecotoxicological properties in young
Daphnia magna

Abstract: Abstract Multiwall carbon nanotubes functionalized with 13.8(6) nm maghemite nanoparticles (NPs) have been synthesized by a modified co-precipitation chemical route and characterized using N2 physisorption and in-field 57Fe Mössbauer studies. Textural and hyperfine magnetic properties indicated that this nanohybrid has a strong potential to be applied in magnetic remediation process due to their unique surface features. Moreover, acute toxicity evaluations were performed before in situ applications, where we implemented our nanohybrid in an effluent containing young Daphnia magna biomarker having a mortality percentage not higher than 15% for the selected concentrations. Despite of it, the reproduction rate was affected after two weeks of previous 72 h exposure, but without apparent morphological changes according to optical and scanning electron microscopy. These findings are of crucial interest for long term applications of concentrated NPs in polluted effluents.
PubDate: 2022-12-01

• The effect of annealing atmosphere on the structural properties of
FeSiBPCu alloys with different silicon content

Abstract: Abstract NANOMET-type soft magnetic alloys of Fe82Si4B10P3Cu1 and Fe78Si8B10P3Cu1 were studied. Nanocrystalline alloys were prepared by annealing the amorphous precursors at a temperature of 420 °C for 20 and 60 min in vacuum and in Ar atmosphere. The effect of the annealing atmosphere and time of annealing on the alloy structural and magnetic properties were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy (MS), magnetic measurements and atomic force microscopy (AFM). XRD unveiled partial crystallization of the Fe82Si4B10P3Cu1 alloy and confirmed amorphous structure of the Fe78Si8B10P3Cu1 alloy. The technique also indicated larger grain size after annealing in vacuum as compared to that in argon. MS disclosed the effect of the silicon content on the annealed alloys microstructure, namely the lower relative volumetric fraction of the A8 crystalline phase component for the alloy with 8 at. % Si as compared to the alloy with 4 at. % Si. Variations of the parameters reflecting the magnetic microstructure were also observed and are discussed with relation to different annealing times and atmospheres. Magnetic measurements showed better soft magnetic properties for sample with 8 at. % Si whose coercivity was lower as well as the determined magnetization work. They also indicated lower coercivity for argon annealed samples and showed that longer annealing times are reflected in the increased resultant coercivity. For both studied compositions, the AFM measurements inspecting the morphology of the sample surfaces manifested the presence of lower protrusions on the surfaces of the vacuum annealed samples as compared to the argon annealed ones, where also larger agglomerates were disclosed.
PubDate: 2022-11-08
DOI: 10.1007/s10751-022-01806-1

• Mössbauer study of long-term stability of alkali-poor solid potassium
ferrate(VI) as a potential oxidation agent for industrial wastewater
treatment

PubDate: 2022-10-27
DOI: 10.1007/s10751-022-01805-2

• Body-centered-cubic structure as a basis for deriving the intermetallic
crystal structures

Abstract: Abstract A model has been devised to derive the intermetallic structure from the bcc- Fe unit cell. The fundamental finding is of special interest because the recent investigation clarifies that there is substantial evidence that atomic arrangements of transition metal-rich amorphous alloys are made of distorted bcc structure. The disordered bcc structure is thermodynamically in a metastable state, the heat treatment leads by crystallization of amorphous alloys to a stable state. In the past, a great deal has been made to describe the process of crystallization of amorphous alloys, but unfortunately, the disordered bcc-Fe regions of amorphous alloys have been neglected. Since the crystallization process takes place from the disordered bcc-regions of amorphous state, it is advisable to reexamine, discuss, and, where necessary to modify the product of the crystallization by the experimental achievements. It is therefore the objective of the present investigation to devise a model based on experimental facts. The atomic size of metalloid atoms determines the crystallization and crystal growth of amorphous alloy. Regardless of their structure, Mössbauer investigation on Fe-rich Metal-Metalloid alloys indicates that the metalloid atoms such as B, P, C, and Ge tend to act with iron by spending their electrons into the Fe 3d-band.
PubDate: 2022-04-06
DOI: 10.1007/s10751-022-01804-3

• Characterization of Spanish River Carbonatite (SRC) for agricultural
fertilizer

Abstract: Abstract Carbonatite is an igneous rock that is composed mainly of carbonate minerals and silicates. It is recently applied as fertilizer due to its high content of calcite and dolomite. This study presents a physical and chemical characterization of the Spanish River Carbonatite (SRC) and its application as fertilizer is tested. The chemical composition obtained by X-ray fluorescence and Energy Dispersive X-ray analyses indicates that Ca, Fe and Si are the main contained elements. Calcite and SiO2 are the principal mineralogical phases as detected by X-ray diffraction. Fourier transform infrared spectroscopy confirms the presence of calcite, silicates and also organic material and water. It also suggests the presence of vermiculite. Thermal analysis reveals only a one-step reaction that corresponds to the decomposition of calcite. Mössbauer spectroscopy performed at room temperature do not show magnetic order between the iron moments instead it shows Fe2+ and Fe3+ doublets in M1 and M2 octahedral sites belonging to vermiculite. At 50 K, we observe that the isomer shift increases their values due to the second order Doppler shift. SQUID magnetometry measurements reveal that most of the sample contains paramagnetic domains assigned to the silicates and calcite components. However, under low applied fields, a tiny signal for Verwey transition appears at 124 K (suggesting the presence of magnetite) although screened by the strong paramagnetic signal of the main components. The SRC has been tested as potential fertilizer on sweet cucumber (Solanum muricatum) which responded positively to the application to carbonatite as an amendment, expressing itself in high foliar biomass.
PubDate: 2022-03-19
DOI: 10.1007/s10751-022-01803-4

• Characterization of nanosized metallic interfaces

Abstract: Abstract The focus of this investigation is the interface regions in crystalline Fe-nanoparticles as well as amorphous nanograins with an average grain size of about 4 nm. The iron nanograins have been compacted under external pressure; the resulting region of the contact between the grains is called an interface. It was found that the interface was three-dimensional with an atomic order different from that present in the neighboring nanograins. The structure of the interfacial region between adjacent amorphous grains has been found to be similar to those in crystalline Fe-nanograins. In other words, the structure of the interface formed under external pressure is independent of the structure of the adjacent grains. The effect of the structure of the interfaces on the magnetic hyperfine interactions and the magnetic moments is studied. In addition, the atomic structures of the interfaces have been studied by means of synchrotron high energy X-ray diffraction. The results obtained are presented in the form of radial distribution functions suggesting the following atomic structure of interfaces: (1) a short-range order of clusters with distorted bcc cells and (2) a middle-range (mesoscopic) order different from that of the bcc cells.
PubDate: 2022-03-19
DOI: 10.1007/s10751-022-01792-4

• Evaluation of Nanoparticle-size distribution with Mössbauer Effect
spectroscopy

Abstract: Abstract The Mössbauer effect (ME) spectroscopy is a powerful tool to obtain information about magnetic nanoparticles (NP). Here we correlate parameters that can be obtained from a ME spectrum (relative fractions of magnetite and maghemite and the volume dependent parameter $$\lambda =KV/k_{B}T$$ ) with other relevant quantities, such as DC saturation magnetization and X-ray diffraction NP mean diameter, D $$_\text {XRD}$$ . The study was performed on the decanted pellets of six different batches of NP obtained using the same synthesis procedure. It was observed that $$\lambda ^{1/3}$$ presents a linear correlation with D $$_\text {XRD}$$ from which the effective anisotropy K for the entire ensemble of the batches could be calculated. The fraction of magnetite retrieved from ME spectra was well correlated to the saturation magnetization. In addition, it was observed that the magnetic response of the supernatant obtained after washing and centrifuging the synthesis product, decreases with $$\lambda$$ , according to the fact that larger NP decant more easily during centrifugation.
PubDate: 2022-03-18
DOI: 10.1007/s10751-022-01801-6

• 161Dy synchrotron-radiation-based Mössbauer absorption spectroscopy

Abstract: Abstract We demonstrate a measurement system for synchrotron-radiation-based Mössbauer absorption spectra with 161Dy using the 25.7 keV nuclear first excited state. Mössbauer spectra of DyF3, Dy metal and DyPc2 (Pc = phthalocyaninato) were obtained and the parameters for the hyperfine structure of 161Dy nuclei in them were evaluated to demonstrate the feasibility of this method. Isomer shifts showed that Dy atoms in all of them are in trivalent state although those in Dy metal was in the region of trivalent metal region. The magnetic hyperfine field of Dy metal of 569 ± 1 T agreed with the literature of the Mössbauer experiments. That of DyPc2 of 489 ± 1 T was reasonable because the ground state of DyPc2 were in the state of Jz = ±13/2. Considering the highly penetrative nature of the 25.7 keV incident radiation, it will be straightforward to apply this method for the study of materials under various conditions such as high pressure, high magnetic fields, and reactive atmospheres.
PubDate: 2022-03-16
DOI: 10.1007/s10751-022-01802-5

• Vibrational properties of the mononuclear Fe[HBpz3]2 spin crossover
complex

Abstract: Abstract Within this work, we report the results of nuclear inelastic scattering experiments of the low-spin phase of the iron(II) mononuclear SCO complex Fe[HBpz3]2 and density functional theory based calculations performed on a model molecule of the complex. We show that the calculated partial density of vibrational states based on the structure of a single iron(II) center which is linked by three pyrazole rings to borat is in good accordance with the experimentally obtained 57Fe-pDOS and assign the molecular vibrations to the prominent optical phonons.
PubDate: 2022-03-10
DOI: 10.1007/s10751-022-01798-y

• On the correlation of the 57Fe Mӧssbauer isomer shift and some structural
parameters of a substance

Abstract: Abstract Analysis of the available experimental data on iron compounds has shown the following: The 57Fe Mössbauer isomer shift (IS) depends on the average interatomic distance between the iron ion and the ions of its first coordination sphere (aID), on the chemical nature of these ions, and also on the iron coordination number. An increase in aID and a decrease in the coordination number lead to an increase in IS. For a given polyhedron, the correlation between IS and aID is close to linear with a slope of about 0.04 mm⋅s-1⋅pm-1. A change in the oxidation state of iron (OSFe) affects IS, since a change in OSFe causes a change in aID due to a change in the number of electrons on the valence shell of iron; the more OSFe, the less IS. If the aID of differently charged ions are close (e.g., for the pair H4[Fe(CN)6] and H3[Fe(CN)6]), then the IS values do not differ significantly. A change in the spin state of an iron ion affects IS insofar as this change causes a change in aID. In particular, the transition from the high-spin to the low-spin state in iron(II) spin-crossover compounds leads to a decrease in aID and, accordingly, to a decrease in IS. A change in the spatial structure of the iron coordination polyhedron may affect IS. This was observed when comparing tetrahedral and square-planar iron(II) oxygen polyhedra. The tetrahedral and square-planar oxygen polyhedra of high-spin iron(II) show increased IS values. In terms of the orbital model of the electron shell of the atom, the above data can be explained by the interactions of the 4s-orbital of iron with its other valence orbitals (undergoing hybridization), as well as with the orbitals of the ions surrounding iron (establishing directional chemical bonds). These interactions affect the electron density at the iron nucleus. The corresponding contributions depend on the distances between the iron ion and the ions surrounding it, but do not depend on the number of orbitals involved into hybridization or on the number of directional chemical bonds. The electron shell of each ion of the iron polyhedron also makes an additional (non-bonding) contribution to the electron density at the iron nucleus. In some specific cases (e.g., for iron in noble gas matrices), the observed unusually low IS can be explained by the filling of the 4s-orbital of iron with its valence non-bonding electron(s).
PubDate: 2022-03-02
DOI: 10.1007/s10751-022-01795-1

• Characterization of iron oxide waste scales obtained by rolling mill steel
industry

Abstract: Abstract Every year, the steelmaking industry produces millions of tons of slags resulting in pollution to the environment. Among the waste, secondary metals and scales rich in iron oxides are also thrown away. There is a need to treat the steel waste in a reasonably way to protect the environment and proposing new cheap technologies for producing advanced materials. In this study we report the morphological and structural characterization of waste scales generated during roll milling steel process at JSC “Arcelor Mittal Temirtau”. The raw slag and annealed at 1000 °C were measured by X-ray diffraction (XRD), scanning electron microscopy adapted with energy dispersive X-ray (SEM- EDX), magnetometry and Mössbauer Spectroscopy (MS). Fe and O were detected by EDX as main chemical elements and Si, S, Ca, Mg, C and Al as minimal elemental composition. XDR for the raw sample revealed α-Fe2O3 (hematite) and Fe3O4 (magnetite) as principal and secondary phase, respectively; whereas monophasic α-Fe2O3 is detected for the scales annealed at 1000 °C. Magnetometry measurements show the Verwey transition for the raw sample and the Morin transition for the annealed at 1000 °C; those are fingerprints for the presence of magnetite and hematite, respectively. MS measurements for the raw sample consist of 6 small peaks of absorption and a broad two-lines absorption peak in the central part. The doublets are associated to the hyperfine parameters belonging to wustite. Magnetite is related to the hyperfine parameters for two sextets in octahedral Fe2.5+ and tetrahedral Fe3+sites and a small sextet that resembles the Mössbauer parameters of α-Fe2O3. Only a well crystallized and weakly ferromagnetic sextet confirm the presence of α-Fe2O3 phase for the sample annealed at 1000 °C due to thermal oxidation.
PubDate: 2022-03-01
DOI: 10.1007/s10751-022-01800-7

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