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1

30 lat mössbauerowskich badań meteorytów w Polsce

Gałązka-Friedman Jolanta, Jakubowska Martyna, Woźniak Marek, Brzózka Katarzyna, Grabias Agnieszka, Szopa Krzysztof

Postępy Fizyki

|

2024

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T. 75, z. 2

3--16

PL

Spektroskopia mössbauerowska57 Fe jest jedną z najczęściej stosowanych metod badania meteorytów. Początek badań mössbauerowskich w Polsce związany jest z meteorytem Baszkówka, który spadł 25.08.1994 w okolicach Warszawy. W artykule przedstawione są niektóre wyniki 30-letnich mössbauerowskich badań meteorytów, otrzymane przez polski zespół badawczy. Do najważniejszych osiągnięć naszej grupy należy opracowanie metody klasyfikacji chondrytów zwyczajnych, które stanowią 87% meteorytów znajdowanych na powierzchni Ziemi. Metoda ta nazwana przez nas metodą 4M (od angielskojęzycznych terminów meteorites, Mössbauer spectroscopy, multidimensional discriminant analysis, Mahalanobis distance) jest metodą ilościową, wykorzystującą pewne systematyczności w mössbauerowskich widmach chondrytów zwyczajnych.1 Podstawowym elementem metody 4M jest baza danych, która w tej chwili składa się z wyników mössbauerowskich pomiarów 87 próbek meteorytów. W artykule omówione są również nowe fazy mineralne zidentyfikowane w meteorycie Morasko. Podano przykłady zastosowania spektroskopii mössbauerowskiej do odróżniania próbek meteorytopodobnych od prawdziwych meteorytów. Omówiliśmy też nasze plany związane z badaniem mechanizmu powstawania chondrytów zwyczajnych oraz z zastosowaniem spektroskopii mössbauerowskiej w przyszłych misjach kosmicznych. Te ostatnie problemy będą rozwiązywane we współpracy z czeską pracownią mössbauerowską Uniwersytetu Palackiego w Ołomuńcu.

EN

57Fe Mössbauer spectroscopy is one of the most commonly used methods for studying meteorites. The beginning of Mössbauer research in Poland is associated with the Baszkówka meteorite, which fell on 25 August 1994 near Warsaw. The article presents some of the results of 30 years of Mössbauer studies of meteorites by the Polish team. One of the most important achievements of our group is the development of a classification method of ordinary chondrites, which constitute 87% of meteorites found on the earth’s surface. This method, which we call the 4M method (meteorites, Mössbauer spectroscopy, multidimensional discriminant analysis, Mahalanobis distance), is a quantitative method that uses certain systematicity in the Mössbauer spectra of ordinary chondrites. The basic element of the 4M method is the database, which currently consists of the results of Mössbauer measurements of 87 meteorite samples. The article also discusses the new mineral phases identified in the Morasko meteorite. Examples of the use of Mössbauer spectroscopy to distinguish meteorite-like samples from real meteorites are given. Our research plans related to the study of the formation mechanism of ordinary chondrites and the use of Mössbauer spectroscopy in future space missions are also discussed. The latter issues will be undertaken in cooperation with the Mössbauer laboratory at Palacký University in Olomouc (Czech Republic).

2

High temperature transformation of iron-bearing minerals in basalt: Mössbauer spectroscopy studies

Kądziołka-Gaweł Mariola, Wojtyniak Marcin, Klimontko Joanna

Mineralogia

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2022

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Vol. 53, iss. 1

10--19

EN

The high temperature decomposition of basalt from Lower Silesia (Poland) was followed by Mössbauer spectroscopy investigation. The Fe content of the sample was ~9.0 at.%. The X-ray diffraction analysis shows that augite (37%) and olivine (12%) are major Fe-bearing mineral components. The sample also contains significant amount of anorthite (22%) and nepheline (17%). The sample was heated at various temperatures between 200o C and 1100o C for three hours. Up to a temperature of 500o C changes in contribution of Fe-bearing minerals are insignificant. Heating in the temperature range from 500o C to 1100o C leads to a systematic increase in contribution of iron oxides at the cost of contribution of silicate minerals, like augite and olivine. Mössbauer spectrum obtained after heating at 1100o C showed hematite as the main iron oxide phase. The ratio of Fe3+/Fetot in the non-heated sample was equal to 0.51 and after heating at 1100o C this ratio amounted to 0.89.

3

Influence of Fe, Cr, and Cu addition on the microstructure, hardness, and anticorrosion properties of Al-Ni-Y alloys

Babilas Rafał, Młynarek-Żak K., Łoński W., Bukowiec D., Lis M., Kądziołka-Gaweł M., Warski T., Radoń A.

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e82, 1--15

EN

This study evaluated the structural changes of Al-Ni-(Fe,Cr,Cu)-Y alloys induced by different cooling states. The aim was to determine the role of Fe, Cr, and Cu addition as well as cooling rate on the structure, hardness and anticorrosion properties of crystalline and nanocrystalline Al-Ni-Y alloys. The impact of the preparation method on the structure of alloys was observed by the broadening of the X-ray diffraction peaks of the alloys in the form of plates, which indicated structure fragmentation at a high cooling rate. The TEM images showed the formation of a structure composed of homogeneously dispersed α-Al nanograins. Phase analysis performed using X-ray diffraction method and Mossbauer spectroscopy revealed that the slowly cooled master alloys were mainly composed of Al23Ni6Y4, Al10Fe2Y, and α-Al phases. The Al10Fe2Y structure was the main Fe-bearing phase in all investigated master alloys. A crystallization mechanism was proposed based on the DTA heating and cooling curves. The pitting corrosion type was identified based on morphology observations after electrochemical tests. Rapid solidification and the addition of chromium and copper improved the microhardness as well as corrosion resistance. The high increase of hardness (289 HV0.1) and corrosion resistance[...]

4

A multi-analytical approach for the analysis of cation distribution in a aluminoceladonite structure

Kądziołka-Gaweł Mariola, Dulski Mateusz, Czaja Maria, Krzykawski Tomasz, Szubka Magdalena

Acta Geologica Polonica

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2022

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Vol. 72, no. 3

353--368

EN

In this paper cation arrangement in two samples of aluminoceladonite, emerald green and dark-green were studied by Mössbauer, Raman and X-ray photoelectron spectroscopies. The X-ray photoelectron spectroscopy (XPS) spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p, and O1s core levels provided information, for the first time highlighting a route to identify the position of Si, Al, K, and Fe cations in a structure of layered silicates. The XPS analysis showed the presence of Al in tetrahedral and octahedral coordination while the K2p line indicated the possibility of K+ substitution by other cations in interlayer sites. Mössbauer spectroscopy provided information about crystal chemistry with respect to the local electronic and geometric environment around the Fe atom and to distortions of the polyhedra. It turned out that iron was located mostly in the cis-octahedra position wherein about 75% of iron appeared in the form of Fe3+. The most preferred cation combinations around Fe corresponded to 3Fe3+ ions and MgFe2+Fe3+/2MgFe3+. Raman spectroscopy illustrated aluminium substitution in silicon and iron positions wherein the concentration of the aluminium determined the degree of structural distortion within the layered system. These isomorphic substitutions implied a typical band arrangement in the hydroxyl region, which has not been observed in celadonites so far.

5

Spektroskopia mössbauerowska jako narzędzie do badania kosmosu i mózgu

Duda Przemysław

Prace Naukowe Politechniki Warszawskiej. Fizyka

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2021

|

z. 60

3--115

PL

W niniejszej pracy przedstawione zostały wyniki badań meteorytów i próbek biologicznych, przeprowadzonych w ostatnim czasie w kierowanym przeze mnie Laboratorium Spektroskopii Mössbauerowskiej. Badania te dotyczyły między innymi opracowania nowej metody pozwalającej na dokonywanie wstępnej klasyfikacji chondrytów zwyczajnych. Równolegle do badań dotyczących meteorytów zostało zaproponowane użycie spektroskopii mössbauerowskiej do badania próbek biologicznych. Widma mössbauerowskie chondrytów zwyczajnych składają się z dwóch dubletów ze względu na obecność żelaza paramagnetycznego w oliwinach i piroksenach oraz dwóch sekstetów pochodzących od magnetycznie uporządkowanego żelaza obecnego w fazach metalicznych i troilicie. Powierzchnie spektralne różnych faz mineralogicznych w meteorytach, określone przez zastosowanie spektroskopii mössbauerowskiej, są proporcjonalne do liczby atomów żelaza w danej fazie mineralogicznej. Ta właściwość widm mössbauerowskich stanowiła podstawę do skonstruowania metody klasyfikacji chondrytów zwyczajnych. Metoda ta wykorzystuje pola powierzchni spektralnych widm mössbauerowskich, które analizowane są za pomocą wielowymiarowej analizy dyskryminacyjnej i odległości Mahalanobis. Metoda ta nosi nazwę 4M i pozwala określić prawdopodobieństwo przynależności chondrytu zwyczajnego do danego typu - H, L lub LL. Spektroskopia mössbauerowska nie jest rutynowo stosowana do oznaczania stężenia żelaza. Ponieważ jednak ta metoda nie wymaga wstępnej obróbki próbek przed pomiarem, może mieć ona ogromne znaczenie dla oceny stężenia żelaza w próbkach, które można następnie wykorzystać do dalszych badań. Próbki biologiczne są tego dobrym przykładem. Uważa się, że żelazo może odgrywać ważną rolę w neurodegeneracji. W pracy przedstawione zostały wyniki badań porównawczych obszarów ludzkiego mózgu (kontrolnych i patologicznych), przeprowadzonych za pomocą technik spektroskopii mössbauerowskiej i obrazowania metodą rezonansu magnetycznego. Spektroskopia mössbauerowska wykazała wyższe stężenie żelaza w atypowym parkinsonizmie (nazywanym postępującym porażeniem nadjądrowym) w obszarach mózgu takich jak istota czarna (substantia nigra) oraz gałka blada (globus pallidus) w stosunku do próbek stanowiących grupę kontrolną. W pozostałych chorobach neurodegeneracyjnych nie zarejestrowano wzrostu stężenia żelaza w tkankach mózgowych. Ze względu na fakt, że określenie roli żelaza może wnieść bardzo wiele w zrozumienie mechanizmów powstawania i rozwoju chorób neurodegeneracyjnych, badania mössbauerowskie próbek mózgowych stanowią ciekawy i perspektywiczny kierunek badań, który wymaga przeprowadzenia dalszych pomiarów i analiz.

EN

This work presents the recent research results related to meteorites and biological samples conducted in the Mössbauer Spectroscopy Laboratory led by the Author. These studies concerned, among others, the development of a new method allowing for the preliminary classification of ordinary chondrites. Parallel to the research on meteorites, it was proposed to use Mössbauer spectroscopy to study biological samples. The Mössbauer spectra of ordinary chondrites consist of two doublets due to the presence of paramagnetic iron in olivines and pyroxenes and two sextets derived from magnetically ordered iron present in metallic and troilite phases. The spectral areas of various mineralogical phases in meteorites; determined by the use of Mössbauer spectroscopy; are proportional to the number of iron atoms in this mineralogical phase. This property of the Mössbauer spectra formed the basis for constructing a method for classifying ordinary chondrites. This method uses the spectral surface areas of the Mössbauer spectra, which are analysed using multidimensional discriminant analysis and Mahalanobis distances. This method is called 4M and allows one to determine the probability of belonging to one of the types of ordinary chondrites - H, L or LL. Mössbauer spectroscopy in not routinely used to determine iron concentration. However, as this method does not require pre-treatment of samples prior to measurements, it can be of great importance for assessing iron in samples that can then be used for further testing. Here, biological samples are a good example. It is believed that iron can play an important role in neurodegeneration. Thus, the work presents the results of comparative studies of areas of the human brain (control and pathological) carried out using Mössbauer spectroscopy techniques and magnetic resonance imaging. Mössbauer spectroscopy showed a higher concentration of iron in atypical parkinsonism (called progressive supranuclear palsy) in areas of the brain such as substantia nigra and globus pallidus compared to control group samples. In other neurodegenerative diseases, no increase in iron concentration in brain tissues was recorded. Due to the fact that determining the role of iron can contribute a lot to understanding the mechanisms of the formation and development of neurodegenerative diseases, Mössbauer studies of brain samples are an interesting direction of research that requires further measurements and analyses.

6

X-ray diffraction and Mössbauer spectroscopy investigations of the (Al, Ni, Co)-doped AgFeO2synthesized by hydrothermal method

Siedliska Karolina

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2020

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T. 10, nr 4

15--18

EN

Delafossite AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 powders were synthesized by hydrothermal method. The structural analysis and hyperfine interactions investigations were performed by X-ray diffraction and the Mössbauer spectroscopy. It was found that the (Al, Ni, Co)-doped delafossite phases with traces of metallic silver can be obtained during hydrothermal synthesis. Investigations revealed that the type of the incorporated element has an impact on the structural properties of the obtained delafossites. However, doping of cobalt, nickel, and alumina ions to the AgFeO2 delafossite structure does not cause significant changes in the values of the hyperfine interactions parameters. The of the Mössbauer spectra confirm the paramagnetic character of the obtained compounds at room temperature.

PL

Proszkowe próbki delafosytów AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 zostały wytworzone metodą hydrotermalną. Badania pozwalające na analizę strukturalną oraz oszacowanie parametrów oddziaływań nadsubtelnych przeprowadzono z wykorzystaniem dyfrakcji rentgenowskiej oraz spektroskopii efektu Mössbauera. Udowodniono, że za pomocą metody hydrotermalnej istnieje możliwość wytworzenia delafosytu AgFeO2 domieszkowanego jonami glinu, niklu i kobaltu z niewielką ilością zanieczyszczeń metalicznym srebrem. Badania wykazały, że rodzaj domieszki ma wpływ na właściwości strukturalne otrzymanych materiałów. Domieszkowanie jednak nie wpłynęło znacząco na zmiany wartości parametrów oddziaływań nadsubtelnych. Kształt zarejestrowanych widm mössbauerowskich potwierdza paramagnetyzm otrzymanych materiałów w temperaturze pokojowej.

7

Phase Composition of Urban Soils by X-Ray Diffraction and Mössbauer Spectroscopy Analysis

Kierlik P., Hanc-Kuczkowska A., Męczyński R., Matuła I., Dercz G.

Archives of Metallurgy and Materials

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2019

|

Vol. 64, iss. 3

1029--1032

EN

The main purpose of this study was to identify the mineral composition of soil sample taken from the upper layer of topsoil. High absorption of chemical substance is a characteristic for humus-organic layer of topsoil. The source of those substance could be a pollutant emitted to the atmosphere by human activity. The research area includes Upper Silesia region, which is the most industrial region of Poland. In the present study, the phase composition of the top soil separates were analyzed by using X-raydiffraction and Mössbauer spectroscopy. X-ray diffraction analysis revealed the presence of seven mineral phases in the material magnetic separated by lower current (quartz, illite, kaolinite, Fe3+ oxides, hematite, magnetite and pyrite). In case of higher current were identified four phases (quartz, muscovite, kaolinite and K0.94 Na0.06 (AlSi3 O8 )). Mössbauer spectroscopy was used for an extensive analysis of iron-containing phases (pyrrhotite, magnetite, aluminosilicate oxides with Fe3+ and kaolinite/Fe2+ silicate).

8

Thermodynamic properties of dilute Co-Fe solid solutions studied by 57Fe Mössbauer spectroscopy

Konieczny R., Idczak R.

Nukleonika

|

2017

|

Vol. 62, No. 2

109--115

EN

The Co1–xFex alloys where x ranges from 0.01 to 0.06 were measured at room temperature using transmission Mössbauer spectroscopy (TMS). The analysis of the obtained data allowed the determination of the short-range order (SRO), the binding energy Eb between two iron atoms in the studied materials using the extended Hrynkiewicz-Królas idea and the enthalpy of solution HCo-Fe of Fe in Co. The results showed that the Fe atoms dissolved in a Co matrix interact repulsively and the estimated value of HCo-Fe = –0.166(33) eV/atom. Finally, values of the enthalpy of solution were used to predict the enthalpy of mixing for the Co-Fe system. These findings were compared with corresponding data given in the literature, which were derived from calorimetric experiments and from the cellular atomic model of alloys described by Miedema.

9

Synthesis and characterization of AgFeO2 delafossite with non-stoichiometric silver concentration

Siedliska K., Pikula T., Chocyk D., Jartych E.

Nukleonika

|

2017

|

Vol. 62, No. 2

165--170

EN

The simple co-precipitation method was used to prepare AgxFeO2 delafossite with non-stoichiometric silver concentration in the range of x = 0.05–1. The obtained material was investigated using X-ray powder diffraction and 57Fe Mössbauer spectroscopy at room temperature. The structural and hyperfine interaction parameters were recognized in relation with decreasing silver concentration. The study revealed that the delafossite structure of AgxFeO2 was maintained up to x = 0.9; as the range of silver concentration was decreased to 0.05 ≤ x ≤ 0.8, a mixture of AgFeO2, Fe2O3 or/and FeOOH was formed.

10

Structural properties of Mn-substituted hercynite

Jastrzębska I., Bodnar W., Witte K., Burkel E., Stoch P., Szczerba J.

Nukleonika

|

2017

|

Vol. 62, No. 2

95--100

EN

In this work spinel series with the general formula Fe1–xMnxAl2O4 (where x = 0, 0.3, 0.5 and 0.7) were synthesized and characterized with respect to their structure and microstructure. X-ray diffractometry (XRD) was used to identify the phase composition that revealed a single phase spinel material. Rietveld refinements of the XRD patterns were carried out in order to determine the lattice and oxygen positional parameters of the spinel compounds. Mössbauer effect measurements were performed at room temperature to determine the local chemical environment of the Fe ions, their valences, and degrees of spinels inversion. It was shown that an increase in the Mn content led to a decrease in the ratio of Fe2+ to Fe3+. The results obtained from Mössbauer spectroscopy (MS) were used to establish the chemical formulas of the synthesized spinels. Finally, the microstructure that was observed using scanning electron microscopy (SEM) showed a compact microstructure with an octahedral crystal habit.

11

Preliminary results of 57Fe Mössbauer spectroscopy of metamict samarskite after one-hour high temperature annealing in argon

Malczewski D., Grabias A.

Nukleonika

|

2017

|

Vol. 62, No. 2

141--144

EN

The preliminary results of 57Fe Mössbauer spectroscopy and X-ray diffraction (XRD) of fully metamict samarskite dated at ~1500 Ma, which absorbed -dose of 6.5 × 1017 α-decay mg–1, are reported after one-hour annealing at 673, 873, 1173 and 1373 K in argon atmosphere. Metamict minerals contain radioactive elements that degrade their crystal structures over geological time. All the Mössbauer spectra obtained can be fitted to two quadrupole doublets assigned to Fe2+ and Fe3+ in octahedral positions. The relative contribution of Fe2+ (Fe2+/Fe) reaches a minimum of 0.10 at 1173 K.

12

Mössbauer and magnetic studies of FeCoNiCuNbSiB nanocrystalline alloys

Grabias A., Basykh V., Ferenc J., Cieślak G., Kulik T., Kopcewicz M.

Nukleonika

|

2017

|

Vol. 62, No. 2

79--84

EN

Nanocrystalline Fe80–x–yCoxNiyCu1Nb3Si4B12 alloys were prepared by the annealing of amorphous ribbons. Primary crystallization of the alloys annealed at temperatures of between 500 and 550°C was studied by X-ray diffraction and Mössbauer spectroscopy. Magnetic properties of the alloys were investigated using a hysteresis loop tracer and vibrating sample magnetometer. The annealed ribbons are composed of a two-phase nanostructure consisting of bcc Fe-based grains embedded in an amorphous matrix. Conversion electron Mössbauer spectroscopy (CEMS) measurements reveal a more advanced crystallization process in the surface layers when compared with the volume of the ribbons. The degree of saturation magnetization of the nanocrystalline alloys is of about 1.5 T. The coercive fi eld varies from 1.0 to 6.5 A/m and peaks at an annealing temperature of 525°C. Magnetic softening of the nanocrystalline alloys observed after annealing at 550°C is correlated with a volume fraction of the nanocrystalline bcc phase.

13

Mössbauer and heat capacity studies of ErZnSn2

Łątka K., Przewoźnik J., Żukrowski J., Verbovytskyy Y., Gonçalves A. P.

Nukleonika

|

2017

|

Vol. 62, No. 2

129--133

EN

Heat capacity results obtained for the intermetallic compound ErZnSn2 were re-analysed to also consider, apart from the classical Debye model, the anharmonicity of the crystal lattice and the proper set of Einstein modes. The 119mSn Mössbauer technique was applied to derive the hyperfine interaction parameters characteristic of the two inequivalent crystallographic Sn sites in the compound studied. Quadrupole interaction constants, as measured by 119mSn Mössbauer spectroscopy, allowed for estimations of Vzz components of the electric field gradient tensor that exist at both Sn sites in the discussed compound.

14

Microstructure and magnetic properties of amorphous Fe51Co12Si16B8Mo5P8 alloy

Hasiak M., Miglierini M., Amini N., Bujdoš M.

Nukleonika

|

2017

|

Vol. 62, No. 2

85--89

EN

Microstructure and thermomagnetic characteristics of the amorphous Fe51Co12Si16B8Mo5P8 alloy in the as-quenched state and after 1 h of annealing at 573 K and 773 K are studied. The structural investigations performed by Mössbauer spectroscopy and X-ray diffractometry confirmed the amorphous structure of the analysed materials. An increase in the annealing temperature up to 773 K does not lead to crystallization of the amorphous alloy. Only structural rearrangement that causes changes in the topological short-range order and annealing out of free volume is observed. This behaviour was confi rmed by modifications of the shapes of hyperfi ne field distributions derived from the corresponding Mössbauer spectra of the investigated alloys. The Curie temperatures of the as-quenched and annealed Fe51Co12Si16B8Mo5P8 alloy at 573 and 773 K are 400, 405 and 421 K, respectively.

15

Hyperfine interactions and some thermomagnetic properties of amorphous FeZr(Cr)NbBCu alloys

Łukiewska A., Olszewski J.

Nukleonika

|

2017

|

Vol. 62, No. 2

135--140

EN

In this research, we studied the magnetic phase transition by Mössbauer spectroscopy and using vibrating sample magnetometer for amorphous Fe86–xZr7CrxNb2Cu1B4 (x = 0 or 6) alloys in the as-quenched state and after accumulative annealing in the temperature range 600–750 K. The Mössbauer investigations were carried out at room and nitrogen temperatures. The Mössbauer spectra of the investigated alloys at room temperature are characteristic of amorphous paramagnets and have a form of asymmetric doublets. However, at nitrogen temperature, the alloys behave like ferromagnetic amorphous materials. The two components are distinguished in the spectrum recorded at both room and nitrogen temperatures. The low field component in the distribution of hyperfine field induction shifts towards higher field with the annealing temperature. It is assumed that during annealing at higher temperature, due to diffusion processes, the grains of α-Fe are created in the area corresponding to this component. Both investigated alloys show the invar effect and the decrease of hyperfine field induction after annealing at 600 K for 10 min is observed. It is accompanied by the lowering of Curie temperature.

16

Compositional dependence of hyperfine interactions and magnetoelectric coupling in (BiFeO3)x-(BaTiO3)1–x solid solutions

Kowal K., Guzdek P., Kowalczyk M., Jartych E.

Nukleonika

|

2017

|

Vol. 62, No. 2

117--122

EN

In this work the compositional dependence of hyperfine interactions and magnetoelectric coupling in (BiFeO3)x-(BaTiO3)1–x solid solutions where x = 0.5–0.9 fabricated from commercial BaTiO3 in terms of the solid-state sintering method at various temperatures and over different time periods is described. In general, as the content of BaTiO3 increases, a decrease in the hyperfine magnetic field (Bhf) at 57Fe nuclei was observed. However, for samples exhibiting lower homogeneity in which the ions of Bi3+ and Fe3+ are replaced by Ba2+ and Ti4+ with lower probability, higher values of Bhf are obtained. For the sample where x = 0.6 that exhibits the coexistence of rhombohedral, regular and tetragonal phases, the highest value of the αME coefficient (3.57 mV/A) was observed, which is more than three times higher when compared to the hitherto published results.

17

An example of the application of Mössbauer spectroscopy for determination of concentration of iron in lyophilized brain tissue

Rzepecka P., Duda P., Giebułtowicz J., Sochacka M., Friedman A., Gałązka-Friedman J.

Nukleonika

|

2017

|

Vol. 62, No. 2

159--163

EN

Mössbauer spectroscopy is not routinely used for the determination of the concentration of iron. However, as this method does not need any pre-treatment of samples before measurements, it may be of extreme importance for the assessment of iron in samples, which can then be used for further investigations. Biological samples are a good example, however, as the concentrations of iron are very low in these, it is important to exclude possible artefacts from the background spectrum related to iron present in the counter and cryostat windows. The aim of this study was to compare two methods of determination of the amounts of iron in investigated sample: one, in which the background spectrum was subtracted from the sample spectrum measured, and the other, in which the obtained non-elaborated spectrum was fitted with two doublets – a doublet for the measured sample and a doublet for the background spectrum. Three samples containing known amounts of natural iron (400, 800 and 1600 µg) and a sample of lyophilized human brain tissue obtained from globus pallidus were assessed. Both methods led to the creation of a very good calibration curve with a correlation coefficient of 0.99. Although both methods gave similar results for the concentration of iron in the sample, the subtraction of the background spectrum had a significantly lower error of the final result.

18

57Fe Mössbauer spectroscopy investigations of iron phase composition in fluidized beds from the ELCHO power plant in Chorzów, Poland

Kądziołka-Gaweł M., Smolka-Danielowska D.

Nukleonika

|

2017

|

Vol. 62, No. 2

101--107

EN

The study investigates the physical and chemical properties of fly ash and bottom ash from a power plant ELCHO in Chorzów, Poland. Coal combustion products generated in the process of combustion in circulating fluidized beds (CFBs) are considerably different from fly and bottom ashes obtained from dust furnaces and multi-layer ones. The composition of the iron-bearing phase in the waste of circulating fluidized bed combustion was determined using Mössbauer spectroscopy and X-ray powder diffraction (XRD) methods.

19

Phase transitions of ferruginous minerals in the course of thermal processing of feldspar-quartz raw materials from the Sobótka region (Lower Silesia)

Lewicka E.

Gospodarka Surowcami Mineralnymi

|

2017

|

T. 33, z. 1

93--110

EN

This paper presents the results of analyses of feldspar-quartz raw materials from deposits of leucogranites located in the Sobótka region. This is a successive stage of research carried out by the author on reasons for colour variation of ceramic materials obtained from them. This step encompassed the firing of sample pairs of analogous chemical composition in different conditions: in a standard cycle lasting more than 2 hours (at a maximum temperature of 1200°C), and a fast one – lasting around 50 minutes (at a max. temperature of 1260°C). The obtained ceramic bodies were analysed using the XRD method, scanning microscopy SEM-EDS and 57Fe Mössbauer spectroscopy at room temperature. The XRD investigations revealed the presence of quartz in both samples, while remnants of sodium feldspar were observed in the one fired in the fast cycle. The scanning microscopy confirmed that the principal component of the examined bodies is the aluminosilicate melt, resulting from the thermal decomposition of mainly feldspars and quartz. Single quartz grains and other minerals of high melting temperatures, i.e. zirconium, were also observed in the course of microscopic examinations. Products of other mineral phases’ transformations at high temperature, such as: titanomagnetite (spinel Fe-Ti), magnetite, biotite, xenotime, sphalerite as well as probably chlorites and garnets, were also relatively frequent. Mössbauer studies demonstrated the presence of three basic components constituting 30% (each) of the spectra, i.e. Fe2O3 (presumably hematite), Fe3+ ions (dispersed in aluminosilicate glassy phase), and nanocrystalline or amorphous oxide phase of iron (Fe-O). Some relatively small amounts (5 and 10%) of mixed valence iron cations (Fe2+/3+) that are not expected to influence the colour difference between samples after firing were also found. A paramagnetic doublet referring to them can be attributed to a titanomagnetite spinel or products of its thermal decomposition. The above-mentioned observations and examinations lead to the finding that the main reason for colour variation in the examined bodies as well as their different microstructure and advancement of phase transitions in the course of firing are different conditions of thermal treatment. These probably also influenced the forms in which iron and other colouring elements occur in the samples studied.

PL

Opracowanie przedstawia wyniki badań kopaliny skaleniowo-kwarcowej pochodzącej ze złóż leukogranitów z rejonu Sobótki. Jest to kolejny etap prowadzonych przez autorkę badań nad wpływem składu chemicznego i mineralnego tych utworów na barwę uzyskanych z nich tworzyw ceramicznych. Obejmował on wypalanie par próbek o analogicznym składzie chemicznym w odmiennych warunkach: w cyklu standardowym, trwającym ponad 2 godziny (w maksymalnej temperaturze 1200°C), oraz szybkim, około 50-minutowym (w maks. 1260°C). Uzyskane tworzywa zostały poddane analizie rentgenowskiej, a także badaniom metodą mikroskopii skaningowej SEM-EDS i spektroskopii mössbauerowskiej w temperaturze pokojowej. Analiza rentgenowska ujawniła obecność kwarcu w obu próbkach, a w przypadku pastylki wypalonej w krótkim cyklu – również reliktów skalenia sodowego. Badania skaningowe potwierdziły, że podstawowym składnikiem badanych tworzyw jest stop glinokrzemianowy, który powstał w wyniku termicznego rozkładu głównie skaleni i częściowo kwarcu. W toku obserwacji stwierdzono obecność pojedynczych ziaren kwarcu oraz innych minerałów cechujących się wysoką temperaturą topienia, takich jak cyrkon. Stosunkowo często obserwowano także produkty przeobrażenia pod wpływem wysokiej temperatury innych faz mineralnych, takich jak: tytanomagnetyt (spinel Fe-Ti), biotyt, ksenotym, sfaleryt oraz przypuszczalnie chloryty i granaty. Badania mössbauerowskie wykazały obecność w tworzywie trzech równorzędnych składowych o względnych zawartościach rzędu 30% każda: Fe2O3 (przypuszczalnie hematyt), kationów Fe3+ (rozproszonych w stopie glinokrzemianowym) oraz słabo krystalicznej względnie amorficznej fazy tlenkowej żelaza (Fe-O). Stwierdzono również występowanie podrzędnej ilości kationów żelaza o mieszanej walencyjności (Fe2+/3+), których względny udział w obu próbkach jest niewielki (10 i 5%) i – jak się przypuszcza – nie może przesądzać o zróżnicowaniu ich zabarwienia. Odpowiadający im dublet paramagnetyczny ma przypuszczalnie związek z obecnością tytanomagnetytu lub produktów jego rozkładu termicznego. Powyższe obserwacje i uzyskane wyniki badań skłaniają do stwierdzenia, że główną przyczyną zróżnicowania barwy próbek są odmienne warunki ich obróbki termicznej, w wyniku czego uzyskano tworzywa różniące się stopniem spieczenia oraz zaawansowania przemian fazowych , co zapewne rzutowało na formę związania żelaza i innych pierwiastków barwiących.

20

Microstructure and Soft Magnetic Properties of Fe-Zr-(Pt)-Nb-Cu-B Amorphous Alloys

Gondro J., Błoch K., Nabiałek M., Walters S.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

707--710

EN

This paper presents the results of investigations into the microstructure and magnetic properties of Fe86Zr7Nb1Cu1B5, Fe82Zr7Nb2Cu1B8 and Fe81Pt5Zr7Nb1Cu1B5 alloys. The alloys were investigated in their as-quenched state, in the form of thin ribbons with approximate dimensions as follows: width 3 mm and thickness 20 μm. The investigations were performed utilizing Mössbauer spectrometry and X-ray diffractometry. Also, an evaluation of the low-field magnetic susceptibility and measurements of the magnetization versus temperature and magnetizing field were performed.