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Sample records for moessbauer spectroscopy study

  1. Moessbauer Spectroscopy study of Quimsachata Volcano materials

    International Nuclear Information System (INIS)

    Dominguez, A.G.B.

    1988-01-01

    It has been studied volcanic lava from Quimsachata Volcano in Pem. Moessbauer Spectroscopy, X-ray diffraction, electronic and optical microscopy allowed the identification of different mineralogical phases. (A.C.AS.) [pt

  2. Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Gonser, U.

    1975-01-01

    This book is addressed to persons interested in learning about what has been done and what can be done with Moessbauer spectroscopy. In an introductory chapter the basic principle is explained and the general parameters governing Moessbauer spectroscopy are tabulated. For the following chapters various disciplines are chosen and the wide applicability of this measuring technique is demonstrated. The second chapter discusses a few representative examples of chemical interesting information being reflected by isomer shifts and quadrupole splittings, particularly with respect to bonding and structural properties. The third chapter deals with some applications of Moessbauer spectroscopy for characterizing magnetic compounds and its use for magnetic structure investigations, particularly by making use of polarized radiation. The fourth chapter describes the use of the Moessbauer spectroscopy for studying iron in biological molecules. As an example of recent applications to mineralogy and geology the results of the studies of lunar samples are reviewed in the fifth chapter. Finally, in the last chapter, work is described on the use of Moessbauer spectroscopy in physical metallurgy, particularly quantitative analyses which have enabled metallurgists to solve many old problems. (orig./FW) [de

  3. Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Zemcik, T.

    1984-01-01

    The emission and absorption of photons taking place without changes in the frequency spectrum of the crystal lattice are known as the Moessbauer effect. It takes place in the low energy levels of heavy nuclei in solid lattices at low temperatures. On the basis of the hyperfine structure of Moessbauer spectra the notions are explained of isomer shift, quadrupole splitting and magnetic splitting. The principle and function are explained of Moessbauer spectrometers and the methods of graphical processing of spectra, also the use of the least square fit. Moessbauer spectroscopy is nondestructive, highly sensitive and selective and makes structural resolution possible. It is used for quantitative and qualitative analysis of compounds. Examples are given of the use of this method for mineralogical and crystallo-chemical analysis of lunar minerals and rocks, for analysis of corrosion products of iron and for phase analysis of alloys. (M.D.)

  4. Moessbauer spectroscopy in studies of photosynthesis

    International Nuclear Information System (INIS)

    Burda, Kvetoslava

    2008-01-01

    Photosynthesis is a process occurring in certain species of bacteria, algae and higher plants. It transforms solar energy into various forms of energy-rich organic molecules. Photosystem II (PSII) is the 'heart' of the photosynthetic apparatus because it delivers electrons and protons for further steps of the light-driven phases of photosynthesis. There are two enigmatic iron binding structures within the core of photosynthetic apparatus, which play an important role in the electron transfer within PSII. Many investigations focus on the determination of their function which is the key to the understanding of the molecular mechanism of the energy and electron transfer within PSII. Among many methods used in this research field, the Moessbauer spectroscopy is a unique one, which gives the possibility to study changes of the valence and spin states of those two iron sites and the dynamical properties of their protein matrix in the presence of various physiological and stress conditions.

  5. Application of Moessbauer spectroscopy to study corrosion

    International Nuclear Information System (INIS)

    Ramshesh, V.; Ravichandran, K.; Venkateswarlu, K.S.

    1976-01-01

    The system components in a nuclear power station include steel, stainless steel and various alloys such as Monel, Inconel, Stellite etc. Usually water/heavy water used as the coolant flows at high temperatures and pressures. Under such conditions the interaction of system components with the coolant produces a host of corrosion products. The deposition of such products is essential. This report attempts to review the salient features of identification of such corrosion products using Moessbauer spectroscopy. (author)

  6. Dedicated detectors for surface studies by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bibicu, I.; Rogalski, M.S.; Nicolescu, G.

    2001-01-01

    Moessbauer spectroscopy is a nuclear resonance method largely utilized in solid state studies. Following resonant nuclear absorption, gamma radiations, conversion X-rays, conversion or Auger electrons are emitted. By detection of gamma radiations information about the sample as a whole are obtained while by detection of electrons or X radiation one obtains data on the surface layer. Our laboratory was among the firsts to produce and use flow gas proportional detectors for surface studies by Moessbauer spectroscopy. Four types of detectors were devised: - detectors for electron detection (90% He + 10% CH 4 ); - detectors for conversion X-ray detection (90% Ar + 10% CH 4 ); - detectors for electrons or internal conversion X rays; - detectors for simultaneous detection of electrons and conversion X rays emitted from the same source. All detectors allow simultaneous Moessbauer measurements both for surface and volume for a given sample. Details of construction are presented for the four types of detectors

  7. Moessbauer spectroscopy. Tutorial book

    International Nuclear Information System (INIS)

    Yoshida, Yutaka; Langouche, Guido

    2013-01-01

    First textbook on Moessbauer Spectroscopy covering the complete field. Offers a concise introduction to all aspects of Moessbauer spectroscopy by the leading experts in the field. Tutorials on Moessbauer Spectroscopy. Since the discovery of the Moessbauer Effect many excellent books have been published for researchers and for doctoral and master level students. However, there appears to be no textbook available for final year bachelor students, nor for people working in industry who have received only basic courses in classical mechanics, electromagnetism, quantum mechanics, chemistry and materials science. The challenge of this book is to give an introduction to Moessbauer Spectroscopy for this level. The ultimate goal of this book is to give this audience not only a scientific introduction to the technique, but also to demonstrate in an attractive way the power of Moessbauer Spectroscopy in many fields of science, in order to create interest among the readers in joining the community of Moessbauer spectroscopists. This is particularly important at times where in many Moessbauer laboratories succession is at stake.

  8. Moessbauer spectroscopy study of iron corrosion underneath painting system

    International Nuclear Information System (INIS)

    Nigam, R.K.; Hajela, B.P.; Sengupta, S.; Srivastava, B.C.; Gupta, K.N.

    1986-01-01

    The effect of pigments on the development of corrosion products between the painting system and metal surface when exposed to marine environments has been discussed. The pigments studied were: red mud zinc chromate, zinc chromate, red oxide zinc phosphate, manganese phosphate barium chromate and basic lead silico chromate. Moessbauer spectroscopy revealed that the upper rust layer in all the cases consisted of γ-Fe 2 O 3 , γ-FeOOH and α-FeOOH. The lower rust layer immediately in contact with the metal surface consisted of an asymmetrical doublet due to γ-FeOOH. (Auth.)

  9. Pottery from a Chimu Workshop Studied by Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Tschauner, H.; Wagner, U.

    2003-01-01

    Ceramic finds from a pottery workshop in the Lambayeque valley were studied by neutron activation analysis, Moessbauer spectroscopy and X-ray diffraction in an attempt to assess an advanced division of labour on the North Coast of Peru during the Chimu period (AD 1350-1460). The study suggests that the material was predominantly fired in a reducing environment with partial reoxidation at the end of the firing cycles, although firing in an oxidising atmosphere has taken place occasionally. The observed variation of firing conditions is characteristic for the use of pit kilns. The results of the archaeometric studies confirm the stylistic studies and show that pottery was no status symbol and far less important as a carrier of Chimu style than metal artefacts.

  10. Comparative Study of Human Liver Ferritin and Chicken Liver by Moessbauer Spectroscopy. Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M. I. [Ural State Technical University - UPI, Division of Applied Biophysics, Faculty of Physical Techniques and Devices for Quality Control (Russian Federation); Milder, O. B.; Semionkin, V. A. [Ural State Technical University - UPI, Faculty of Experimental Physics (Russian Federation); Prokopenko, P. G. [Russian State Medical University, Faculty of Biochemistry (Russian Federation); Malakheeva, L. I. [Simbio Holding, Science Consultation Department (Russian Federation)

    2004-12-15

    A comparative study of normal human liver ferritin and livers from normal chicken and chicken with Marek disease was made by Moessbauer spectroscopy. Small differences of quadrupole splitting and isomer shift were found for human liver ferritin and chicken liver. Moessbauer parameters for liver from normal chicken and chicken with Marek disease were the same.

  11. Comparative Study of Human Liver Ferritin and Chicken Liver by Moessbauer Spectroscopy. Preliminary Results

    International Nuclear Information System (INIS)

    Oshtrakh, M. I.; Milder, O. B.; Semionkin, V. A.; Prokopenko, P. G.; Malakheeva, L. I.

    2004-01-01

    A comparative study of normal human liver ferritin and livers from normal chicken and chicken with Marek disease was made by Moessbauer spectroscopy. Small differences of quadrupole splitting and isomer shift were found for human liver ferritin and chicken liver. Moessbauer parameters for liver from normal chicken and chicken with Marek disease were the same.

  12. Moessbauer studies of Inca ceramics

    International Nuclear Information System (INIS)

    Wagner, U.; Wagner, F.E.; Marticorena, B.; Salazar, R.; Schwabe, R.; Riederer, J.

    1986-01-01

    To obtain information on the firing of Inca ceramics, 7 samples from different locations were studied by Moessbauer spectroscopy including a detailed laboratory refiring procedure. The glaze typical for the surface of this ware was studied by Moessbauer scattering. (Auth.)

  13. Study of a low alloy steel rust using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Maier, I.A.; Saragovi-Badler, C.; Labenski, F.

    1978-01-01

    Moessbauer spectroscopy has been used to analyze the internal and external rust layers of a weathering steel exposed for ten months to an urban-industrial atmosphere. Superparamagnetic α-FeOOH and γ-FeOOH were found in both layers. The external one also contained small sized delta-FeOOH and/or amorphous iron oxyhydroxide. These compounds were not present in the internal layer at this stage of the patina formation. (author)

  14. Lattice dynamic studies from {sup 151}Eu-Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Katada, Motomi [Tokyo Metropolitan Univ., Hachioji (Japan). Faculty of Science

    1997-03-01

    New complexes {l_brace}(Eu(napy){sub 2}(H{sub 2}O){sub 3})(Fe(CN){sub 6})4H{sub 2}O{r_brace}{sub x}, bpy({l_brace}(Eu(bpy)(H{sub 2}O){sub 4})(Fe(CN){sub 6})1.5bpy4H{sub 2}O{r_brace}{sub x}) and ({l_brace}(Eu(phen){sub 2}(H{sub 2}O){sub 2})(Fe(CN){sub 6})2phen{r_brace}{sub x}) etc were synthesized using phenanthroline and bipyridine. Lattice dynamic behaviors of Eu and Fe atom in the complexes were investigated by Moessbauer spectroscopy. By {sup 151}Eu-Moessbauer spectrum and parameters of new complexes, bpy complex showed the largest quadrupole splitting value, indicating bad symmetry of Eu ligand in the environment. Molecular structure of napy, bpy and phen complex were shown. These complexes are consisted of Eu atom coordinated with ligand and water molecule, of which (Fe(CN){sub 6}){sup 3-} ion formed one dimentional polymer chain and naphthyridines formed stacking structure. New complexes were observed by {sup 57}Fe-Moessbauer spectroscopy, too. The quadrupole splitting values were very different each other, indicating change of symmetry of Fe atom in the environment and three valence low spin state of Fe in the complex. (S.Y.)

  15. Study of chicken liver and spleen by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural State Technical University-UPI, Division of Applied Biophysics, Faculty of Physical Techniques and Devices for Quality Control (Russian Federation); Milder, O. B.; Semionkin, V. A. [Ural State Technical University-UPI, Faculty of Experimental Physics (Russian Federation); Malakheeva, L. I. [Simbio Holding, Science Consultation Department (Russian Federation); Prokopenko, P. G. [Russian State Medical University, Faculty of Biochemistry (Russian Federation)

    2005-09-15

    A preliminary study of purified normal human liver ferritin, normal chicken liver and spleen tissues in lyophilized form showed differences in room temperature Moessbauer hyperfine parameters. An additional study of liver and spleen tissues with lower iron content from chicken with lymphoid leukemia indicated small differences between the quadrupole splittings in these samples compared with those in normal tissues.

  16. Study of chicken liver and spleen by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Oshtrakh, M. I.; Milder, O. B.; Semionkin, V. A.; Malakheeva, L. I.; Prokopenko, P. G.

    2005-01-01

    A preliminary study of purified normal human liver ferritin, normal chicken liver and spleen tissues in lyophilized form showed differences in room temperature Moessbauer hyperfine parameters. An additional study of liver and spleen tissues with lower iron content from chicken with lymphoid leukemia indicated small differences between the quadrupole splittings in these samples compared with those in normal tissues.

  17. Moessbauer spectroscopy in space

    Energy Technology Data Exchange (ETDEWEB)

    Klingelhoefer, G [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Held, P [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Teucher, R [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Schlichting, F [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Foh, J [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Kankeleit, E [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

    1995-03-01

    Nearly 40 years after the discovery of the Moessbauer effect for the first time a Moessbauer spectrometer will leave our planet to explore in situ the surface of another solar system body: the red planet Mars [1]. We are currently developing a miniaturized Moessbauer spectrometer (MIMOS) which is part of the scientific payload of the Russian Mars96 mission, to be launched within the next 2-4 years [2,3]. To fulfill the requirements for a space mission to the planet Mars, all parts of the spectrometer had to be extremely miniaturized and ruggedized to withstand the space flight and Mars environmental conditions. The relevant parts (e.g. drive, detector system, electronics etc.) will be described in more detail and its characteristics compared to standard systems. Because of this new development there now is a growing interest to include a Moessbauer (MB) instrument in future space missions to other solar system bodies as for instance Venus, the terrestrial Moon, and a comet nucleus. Because of extremely different environmental conditions (e.g. nearly zero gravity on the surface of a comet nucleus, high pressure and temperature on the surface of Venus, etc.) different instrument designs and concepts are required for different missions. We will present some ideas for various types of missions, as well as the motivation for using Moessbauer spectroscopy in these cases. (orig.)

  18. Study by Moessbauer spectroscopy of the iron-dextran (Imferon)

    International Nuclear Information System (INIS)

    Araujo, S.I. de; Danon, J.

    1985-01-01

    The iron-dextran complexes (imferon) are very important in the anemia treatment resulting of the iron insufficiency. Recent studies by electron diffraction denoted that the imferon is structurally different of the ferritin, one protein which constitute the iron reserve substance in the organisms. However, the obtained data in the imferon by Moessbauer spectroscopy, in different temperature ranges (room, liquid nitrogen and liquid He), show a great resemblance between this compound and the ferritin. A Fe 3+ distorted octahedrical coordenation is observed in both compounds, agreeing with measurements done in ferritin by EXAFS. In spite of the concordant results, persist, nevertheless, some discrepancies. The ferritin seems to be a rather more ionic than the imferon, possibly due to the rather higher interatomic distance in the former compound. In these measurements, a field of 484,6 + - 5 KOe is found for the imferon which, compared with the field of 493 + - 10 KOe for ferritin, confirms to be the ferritin more ionic than the imferon. It is, however, a litle difference, when it is compared to the existent between the iron binary oxides β FeOOH and γFeOOH. (L.C.) [pt

  19. Study of iron exchanged zeolites by Moessbauer effect and electron spin resonance spectroscopy

    International Nuclear Information System (INIS)

    Aguirre Campuzano, C.E.

    1993-01-01

    Crystalline iron exchanged NaY zeolites, prepared from aqueous solutions and calcined at atmospheric conditions, have been studied and characterized by XRD, Moessbauer and EPR spectroscopies and TGA analysis. Three iron sites are clearly distinguished from Moessbauer and EPR measurements. Firstly, characteristic Moessbauer and EPR spectra may arise from framework sites, suggesting that Fe has substituted Al. It is also found that their spectroscopic signals are not intensity affected by thermal treatments. Secondly, a Moessbauer doublet which may arise from octahedral sites in the large cavity of the zeolite, shows however, that this doublet and its EPR signal are intensity temperature affected. An additional line broadening is observed on the low velocity line of this doublet, Thirdly, characteristic Moessbauer and EPR signals, which are also intensity temperature dependent have been associated to accluded material, where the Moessbauer doublet presents the line broadening effect before mentioned. Such line broadening effect may be due to perturbing signals from iron ions in tetrahedral sites. Finally, it has been observed that during calcination of the FeY zeolites, the three characteristic EPR signals for the three iron sites, do not increase at the expenses of the other. A result that may suggest a strong bonding between Fe-site of the Y zeolite, irrespective of the iron source. (Author)

  20. {sup 57}Fe quadrupole splitting and isomer shift in various oxyhemoglobins: study using Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural Federal University (The former Ural State Technical University-UPI), Faculty of Physical Techniques and Devices for Quality Control (Russian Federation); Berkovsky, A. L. [Hematological Scientific Center of the Russian Academy of Sciences (Russian Federation); Kumar, A.; Kundu, S., E-mail: sumankundu@south.du.ac.in [University of Delhi South Campus, Department of Biochemistry (India); Vinogradov, A. V.; Konstantinova, T. S. [Ural State Medical Academy, Faculty of Internal Diseases Propedeutics (Russian Federation); Semionkin, V. A. [Ural Federal University (The former Ural State Technical University-UPI), Faculty of Physical Techniques and Devices for Quality Control (Russian Federation)

    2010-04-15

    A comparative study of normal human, rabbit and pig oxyhemoglobins and oxyhemoglobin from patients with chronic myeloleukemia and multiple myeloma using Moessbauer spectroscopy with a high velocity resolution demonstrated small variations of the {sup 57}Fe quadrupole splitting and isomer shift. These variations may be a result of small structural differences in the heme iron stereochemistry of various hemoglobins.

  1. Moessbauer spectroscopy, X-ray diffraction and infrared studies of prehistoric materials from Minas Gerais

    International Nuclear Information System (INIS)

    Jesus Filho, M.F. de; Costa, G.M. da; Prous, A.

    1988-01-01

    Eight samples of pigmented materials from an archaelogical site in Santana do Riacho (Minas Gerais, Brazil) were studied by X-ray diffraction, infrared and Moessbauer spectroscopy. These three techniques and the results of chemical analysis allowed the approximated composition of each sample to be proposed. No trace of organic material was found in any sample. (author)

  2. Moessbauer Spectroscopy in Materials Science

    International Nuclear Information System (INIS)

    2006-01-01

    The publication in electronic form has been set up as proceedings of the conference dealing with applications of the Moessbauer spectroscopy in material science. Twenty-three abstracts and twenty-two presentations are included.

  3. Study of iron valence state and position in sub-site by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Uhm, Young Rang; Lim, Jae Cheong; KIm, Chul Sung; Son, Kwang Jae

    2014-01-01

    The magnetic ordering temperature and the magnitude of the magnetic fields at the iron sites of YIG can be influenced by substituting, either partially or totally, the Fe 3+ ions at the octahedral and/or the tetrahedral sites with magnetic or diamagnetic ions, and/or by substitution the Y 3+ ions at the dodecahedral sites with magnetic rare earth ions. It has been known for some time that Moessbauer spectroscopy is a powerful method by which iron-containing garnets can be studied. We report here on the synthesis of the compounds with garnet-related structures of composition Y 3 Fe 4.5 Cr 0.5 O 12 and its examination by 57 Fe Moessbauer spectroscopy. The chromium in compounds of the Y 3 Fe 4.5 Cr 0.5 O 12 is distributed at an octahedral site. The Moessbauer spectra can be analyzed using 3 or 4 sets of six Lorentzians with increasing amount of Cr 3+ compounds in this system. It results from the distribution ( 4 C n ) of Fe 3+ and Cr 3+ at an octahedral site. A comparative study of ferrous tablets of Dynabi was carried out using Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe 2+ ) gluconate and ferrous fumarate in a sample. This observation is important to better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron. The Cr-containing yttrium iron garnet (YIG), and the exchange interactions and site distributions were studied using 57 Fe Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe 2+ ) gluconate and ferrous fumarate in the sample. This observation is important better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron

  4. Application of Moessbauer spectroscopy to study archaeological Egyptian pottery

    International Nuclear Information System (INIS)

    Eissa, N.A.

    1988-01-01

    Moessbauer spectra have been used as ''fingerprints'' in obtaining information an ancient Egyptian pottery and in fine art. An empirical relation has been found that connects the natural radiation dose with the intensity ratio of the two non-magnetic central peaks. It was suggested that this relation be used for dating ancient pottery. 8 refs, 13 figs, 2 tabs

  5. Study of iron-zinc catalysts by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Arriola, S.H.

    1990-01-01

    The Moessbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. A change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the α-Fe 2 O 3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. A strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using x-ray fluorescence and x-ray diffraction methods. (author) 10 refs.; 4 figs.; 2 tabs

  6. Moessbauer spectroscopy-nuclear hyperfine technique for studying dynamic chemical states of iron complexes

    International Nuclear Information System (INIS)

    Maeda, Y.

    2005-01-01

    A brief introduction of Moessbauer spectroscopy will be presented, followed by a discussion of the Moessbauer parameters, isomer shifts, quadrupole splittings, and spectral shapes of complexes in the presence of relaxation of the electronic states of the iron atoms. The usefulness of Moessbauer spectroscopy to demonstrate the dynamic phenomena of electronic states will be discussed in this lecture. (1) The Moessbauer spectra of mixed valence dinuclear and trinuclear iron complexes will be discussed in connection with the chemical structure of the complexes: The values of the quadrupole splittings and isomer shifts of [Fe II Fe III (bpmp) (ppa) 2 ](BF 4 ) 2 increase on raising the temperature, where Hbpmp represents 2,6-bis[bis(2- pyridylmethyl)aminoethyl]-4-methylphenol and ppa is 3-n-phenylpropionic acid. The spectra can be accounted for by postulating intramolecular electron exchange between two energetically inequivalent vibronic states Fe A 2+ Fe B 3+ and Fe A 3+ Fe B 2+ : The apparent time averaged valence states of the iron atoms are 2.2 and 2.8 on the Moessbauer time scale at 293 K. (2) The Moessbauer spectra of iron(III) spin-crossover complexes will be discussed in connection with the spin-transition rate and chemical structure of the complexes. The Moessbauer spectra of spin-crossover iron(III) complexes with LIESST (Light Induced Electronic Spin-State Transition) and of metallomesogens will be discussed to illustrate the extension of this research area by the use of Moessbauer spectroscopy.

  7. Study of iron valence state and position in sub-site by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Uhm, Young Rang; Lim, Jae Cheong; KIm, Chul Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Son, Kwang Jae [Kookmin Univ., Seoul (Korea, Republic of)

    2014-05-15

    The magnetic ordering temperature and the magnitude of the magnetic fields at the iron sites of YIG can be influenced by substituting, either partially or totally, the Fe{sup 3+} ions at the octahedral and/or the tetrahedral sites with magnetic or diamagnetic ions, and/or by substitution the Y{sup 3+} ions at the dodecahedral sites with magnetic rare earth ions. It has been known for some time that Moessbauer spectroscopy is a powerful method by which iron-containing garnets can be studied. We report here on the synthesis of the compounds with garnet-related structures of composition Y{sub 3}Fe{sub 4.5}Cr{sub 0.5}O{sub 12} and its examination by {sup 57}Fe Moessbauer spectroscopy. The chromium in compounds of the Y{sub 3}Fe{sub 4.5}Cr{sub 0.5}O{sub 12} is distributed at an octahedral site. The Moessbauer spectra can be analyzed using 3 or 4 sets of six Lorentzians with increasing amount of Cr{sup 3+} compounds in this system. It results from the distribution ({sub 4}C{sub n}) of Fe{sup 3+} and Cr{sup 3+} at an octahedral site. A comparative study of ferrous tablets of Dynabi was carried out using Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe{sup 2+}) gluconate and ferrous fumarate in a sample. This observation is important to better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron. The Cr-containing yttrium iron garnet (YIG), and the exchange interactions and site distributions were studied using {sup 57}Fe Moessbauer spectroscopy. The obtained results revealed the presence of ferrous (Fe{sup 2+}) gluconate and ferrous fumarate in the sample. This observation is important better control the iron state in such medicaments because their pharmaceutical effect in the body is related to the form and valence of iron.

  8. Anthracene as a Non-hygroscopic Diluting Agent for Moessbauer Spectroscopy of Silicate Samples in Moisture-Uptake Studies

    International Nuclear Information System (INIS)

    Hoffman, E. J.; Bickraj, K.; Denalli, C.

    2004-01-01

    Anthracene gained no mass when held in a humid chamber and showed no gamma absorption and so appears to be suitable as a replacement for sugars for dilution of moisture-sensitive 57 Fe-Moessbauer spectroscopy samples. Applied to studies of moisture effects on a circumstellar silicate dust simulant, anthracene permitted preparation of sample series for experimental determination of optimal 57 Fe-Moessbauer areal density.

  9. Application of Moessbauer spectroscopy to the study of neptunium adsorbed on deep-sea sediments

    International Nuclear Information System (INIS)

    Bennett, B.A.; Rees, L.V.C.

    1987-03-01

    A Neptunium Moessbauer spectrometer (the first in Great Britain) was constructed and the Moessbauer spectra of NpAl Laves phase alloy obtained. Neptunium was sorbed onto a calcareous deep-sea sediment from sea water, using a successive-loading technique. Sorption appeared to be by an equilibrium reaction, and because of the low solubility of neptunium in seawater, this meant that the maximum loading that could be achieved was 8mg 237 Np/g sediment. This proved to be an adequate concentration for Moessbauer measurements and a Moessbauer spectrum was obtained. This showed that most of the neptunium was in exchange sites and not present as precipitates of neptunium compounds. It was probably in the 4+ state indicating that reduction had occurred during sorption. This work has demonstrated that Moessbauer Spectroscopy has great potential as an aid to understanding the mechanism of actinide sorption in natural systems. (author)

  10. Moessbauer spectroscopy with synchrotron radiation

    International Nuclear Information System (INIS)

    Bergmann, U.

    1994-01-01

    The short pulse nature of synchrotron radiation makes it possible to perform Moessbauer spectroscopy in the time domain, i.e. instead of measuring the transmitted intensity time integrated as a function of source/absorber velocity, the intensity of the scattered radiation is measured time differential. The resulting time spectrum is essentially source independent and complications in the data analysis which are related to the radioactive source are completely removed. Furthermore, the large brightness and well defined polarization of the synchrotron radiation can, e.g., speed up the data collection and facilitate studies of polarization phenomena. To illustrate these new spectroscopic possibilities, measurements of the temperature dependence and polarization dependence of forward scattering from alpha - sup 5 sup 7 Fe nuclei are presented and discussed 26 refs., 5 figs. (author)

  11. Studies on corrosion of mild steel by water using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Nigam, A.N.; Tripathi, R.P.; Jangid, M.L.

    1987-01-01

    The corrosion of mild steel as a result of interaction with various types of local natural water samples and distilled water is studied with the help of Moessbauer spectroscopy. The data are supplemented with the studies on IR and magnetic properties as and when required. Distilled water and potable water behave in almost similar fashion wherein ferrihydrite and FeOOH are observed to be the precursors of magnetite, the end corrosion product. In case of brakish water, the additional species, viz., FeCl 2 , βFeOOH and an intermediate possibly FeOCl are accounted, and possible mechanisms are suggested. (author)

  12. Spin crossover studies in cationic complexes of iron by using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Vadera, S.R.; Kumar, N.

    1990-01-01

    The spin transition in two new cationic complexes of iron, i.e. iron bipyridine formate, [Fe(bipy) 3 ](HCOO) 2 .5(HCOOH) and iron bipyridine tetrafluoro borate, [Fe(bipy) 3 ](BF 4 ) 2 .2H 2 O were studied by Moessbauer spectroscopy. From quadrupole splitting values, it was established that at different temperatures both complexes show the coexistence of both high spin state and low spin state at 300 K, while complete transformation to low spin state occurs at 77 K. Both compounds were prepared by electrochemical technique. (author) 12 refs.; 1 fig.; 1 tab

  13. The 129I hyperfine interaction in fatty acids studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Burda, K.; Strzalka, K.; Stanek, J.

    1993-01-01

    Oleic acid substituted by iodine and saponified by Ca 2+ cations has been studied by 129 I Moessbauer spectroscopy. The quadrupole coupling constants and isomer shifts, determined from the γ-resonance spectra recorded at 4.2 K, have been described by 5p and 5s orbital populations of iodine. It was also found that saponification of the fatty acid has no significant influence on the measured iodine bonds. However, the increased order of fatty acids in soap form is reflected by narrowing of the resonant linewidth due to the reduction of the electric field gradient distribution. (orig.)

  14. Moessbauer spectroscopy study on the hydrothermal transformation α-FeOOH → α-Fe2O3

    International Nuclear Information System (INIS)

    Barb, D.; Diamandescu, L.; Mihaila-Tarabsanu, D.; Rusi, A.; Moraria, M.

    1990-01-01

    The reaction kinetics of the hydrothermal transformation α-FeOOH→α-Fe 2 O 3 was studied by means of Moessbauer spectroscopy. From the reaction isotherms, a monomolecular, first order reaction was found to characterise the hydrothermal transformation of alpha oxihydroxide to the alpha iron oxide. The rate constant as well as the activation energy of this process were determined. No intermediate phases were identified in the hydrothermal samples. The thermodynamic properties of the hydrothermal system α-FeOOH→α-Fe 2 O 3 in correlation with Moessbauer spectroscopy data are discussed. (orig.)

  15. Characterization of catalysts by Moessbauer spectroscopy: An application to the study of Fischer-Tropsch, hydrotreating and super Claus catalysts

    International Nuclear Information System (INIS)

    Kraan, A.M. van der; Boellaard, E.; Craje, M.W.J.

    1993-01-01

    Moessbauer spectroscopy is an excellent in-situ technique for the identification of phases present in catalysts. Applied to metallic iron catalysts used in the Fischer-Tropsch reaction it reveals a detailed picture of the carburization process and provides insight into the relation between the properties of the catalytic material and its activity. The influence of a support and the effect of alloying iron with an (in)active metal on the catalytic performance is discussed for Fe, Cu-Fe and Ni-Fe systems. In addition, Moessbauer spectroscopy is used for the identification of 'Co-sulfide' species present in sulfided Co and CoMo catalysts applied in one of the largest chemical processes in the world, the hydrotreatment of crude oil. A structural model is proposed. Finally, the contribution of Moessbauer spectroscopic studies to the development of a new catalyst for cleaning of Claus tail gas via selective oxidation of hydrogen sulfide to elemental sulfur is discussed. (orig.)

  16. Ball milling of chalcopyrite: Moessbauer spectroscopy and XRD studies

    International Nuclear Information System (INIS)

    Pollak, H.; Fernandes, M.; Levendis, D.; Schonig, L.

    1999-01-01

    The aim of this project is to study the behavior of chalcopyrite under ball milling for extended periods in order to determine how it's decompose or transform. Tests were done with chalcopyrite mixed with iron and zinc with and without surfactant. The use of surfactants has various effects such as avoiding oxidation and clustering of the fine particles. In all case magnetic chalcopyrite is transformed into a paramagnetic component showing a disordered structure, thus revealing that Cu atoms have replaced Fe atoms. In the case of ball milling in air, chalcopyrite is decomposed with the lost of iron, while in milling under surfactants, iron enters into the chalcopyrite structure. (author)

  17. A study of human liver ferritin and chicken liver and spleen using Moessbauer spectroscopy with high velocity resolution

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural State Technical University-UPI, Faculty of Physical Techniques and Devices for Quality Control (Russian Federation); Milder, O. B.; Semionkin, V. A. [Ural State Technical University-UPI, Faculty of Experimental Physics (Russian Federation)

    2008-01-15

    Lyophilized samples of human liver ferritin and chicken liver and spleen were measured at room temperature using Moessbauer spectroscopy with high velocity resolution. An increase in the velocity resolution of Moessbauer spectroscopy permitted us to increase accuracy and decrease experimental error in determining the hyperfine parameters of human liver ferritin and chicken liver and spleen. Moessbauer spectroscopy with high velocity resolution may be very useful for revealing small differences in hyperfine parameters during biomedical research.

  18. Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science)

    1981-06-01

    Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds.

  19. Moessbauer Spectroscopy Studies of Some Intermetallics in the Zr-Nb-Fe System

    International Nuclear Information System (INIS)

    Ramos, C.; Saragovi, C.; Granovsky, M.; Arias, D.

    2002-01-01

    Samples with the following compositions: Zr 62 Nb 14 Fe 24 , Zr 65 Nb 10 Fe 25 and Zr 52 Nb 10 Fe 38 were studied by Moessbauer spectroscopy. All of them showed a ternary cubic Ti 2 Ni-type phase (QS: 0.30±0.02, IS: -0.14±0.01) and traces of Zr 2 Fe phase (QS: 0.86±0.03, IS: -0.29±0.01). Zrβ phase (QS: 0.22±0.01, IS: -0.11±0.01) was also detected except in the case of the richer Fe sample. In addition to these expected phases, a hexagonal MgZn 2 -type phase was determined. The assigned parameters for this phase are: QS: 0.38±0.04, IS: -0.28±0.02. These results suggest a revision of the diagram.

  20. Moessbauer spectroscopy of locally inhomogeneous systems

    International Nuclear Information System (INIS)

    Rusakov, V. S.; Kadyrzhanov, K. K.

    2004-01-01

    Substances with characteristic local inhomogeneities - with different from position to position neighborhood and properties of like atoms - gain recently increased scientific attention and wide practical application. We would call a system locally inhomogeneous if atoms in the system are in non-equivalent atomic locations and reveal different properties. Such systems are, first of all, variable composition phases, amorphous, multi-phase, admixture, defect and other systems. LIS are most convenient model objects for studies of structure, charge, and spin atomic states, interatomic interactions, relations between matter properties and its local characteristics as well as for studies of diffusion kinetics, phase formation, crystallization and atomic ordering; all that explains considerable scientific interest in such LIS. Such systems find their practical application due to wide spectrum of useful, and sometimes unique, properties that can be controlled varying character and degree of local inhomogeneity. Moessbauer spectroscopy is one of the most effective methods for investigation of LIS. Local character of obtained information combined with information on cooperative phenomena makes it possible to run investigations impossible for other methods. Moessbauer spectroscopy may provide with abundant information on peculiarities of macro- and microscopic state of matter including that for materials without regular structure. At the same time, analysis, processing and interpretation of Moessbauer spectra for LIS (that are sets of a large amount of partial spectra) face considerable difficulties. Development of computer technique is accompanied with development of mathematical methods used for obtaining physical information from experimental data. The methods make it possible to improve considerably, with some available a priori information, effectiveness of the research. Utilization of up-to-date mathematical methods in Moessbauer spectroscopy requires not only adaptation

  1. Moessbauer spectroscopy of metals from birth to death

    International Nuclear Information System (INIS)

    Fujita, Francisco Eiichi

    1998-01-01

    In today's metallurgy, precision techniques, such as X-ray and electron diffraction, electron microscopy, infrared spectroscopy and electron probe micro-analyzer, are being indispensably used, and, comparing to them, Moessbauer spectroscopy is not inferior at all in usefulness, convenience and cost benefit. Actually, however, it is not yet popular among the metallurgists probably because people believe that the Moessbauer effect is a difficult physics, radioactive sources are difficult to handle, and spectral analyses are complicated. These beliefs are in fact groundless and must be dissolved for further diffusion of this useful Moessbauer technique in metals and other industries.The present introductory talk intends to help people's better understanding and no anxiety for using the Moessbauer spectroscopy by showing how it can be applied to various problems of metals and alloys from their birth to the end, that is, from the study of minerals and ores before smelting to that of corrosion and other failures.Firstly, the principle of Moessbauer spectroscopy will be explained with simplest illustrations together with simple pictures of apparatuses including the high temperature furnace and the high pressure cell.In the second will be shown typical examples of Moessbauer patterns of magnetite, carbon steel and other alloys, with indications of how to analyze the seemingly complicated spectra. Some other examples will be shown with special apparatuses easy to measure. The usefulness and convenience of Moessbauer spectroscopy will be understood again from these examples. More examples will be on amorphous alloys and other advanced materials

  2. Structural Relaxation in Fe78Nb2B20 Amorphous Alloy Studied by Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Kansy, J.; Hanc, A.; Rasek, J.; Haneczok, G.; Pajak, L.; Stoklosa, Z.; Kwapulinski, P.

    2011-01-01

    It was shown that soft magnetic properties of Fe 78 Nb 2 B 20 amorphous alloy can be significantly improved by applying 1-h annealing at temperature 623 K (permeability increases even about 8 times). The Moessbauer Spectroscopy technique indicated that the optimized microstructure (corresponding to the maximum magnetic permeability) is free of iron nanograins and should be attributed to annealing out of free volume and a reduction of internal stresses i.e. to the relaxed amorphous phase. (authors)

  3. Moessbauer spectroscopy and additional study of neutron irradiated Cr-doped metallic glasses

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Mihalik, M.; Zentko, A.

    1990-01-01

    Concentration and fluence dependent tendency of FeNiCrMoSiB metallic glass towards disordering as well as a decrease of the Curie temperature were revealed by Moessbauer and electron-positron annihilation spectroscopies and initial permeability measurements, respectively. The observed changes can be assigned to irradiation-induced defects resulting in fluctuations in chemical and/or topological short-range order. (orig.)

  4. Hydrogenation of FeCoZr-Al2O3 nanocomposites studied by Moessbauer spectroscopy and magnetometry

    International Nuclear Information System (INIS)

    Saad, A.; Kasiuk, J.; Fedotova, J.; Szilagyi, E.; Przewoznik, J.; Kapusta, Cz.; Marszalek, M.

    2009-01-01

    Hydrogenation effects on crystalline and magnetic structure of nanocomposites (FeCoZr) x (Al 2 O 3 ) 100-x , 38 ≤ x ≤ 63 at.% are studied by 57 Fe Moessbauer spectroscopy and magnetometry. Variations of local structure, blocking temperature and mean FeCoZr nanoparticles' volume are discussed with respect to (i) composition and (ii) two competing processes-H 2 incorporation and annealing-occurred during treatment in H 2 plasma.

  5. Applications of Moessbauer spectroscopy in the study of minerals: some recent trends

    International Nuclear Information System (INIS)

    Danon, J.

    1983-01-01

    Three examples of mineralogy studies in which Moessbauer spectrsocopy is playing a determinant role: magnetic order in silicates, biomineralization of iron by bacteria and order-disorder transitions in Fe-Ni alloys in meteorites are discussed. (L.C.) [pt

  6. Moessbauer spectroscopy study on the corrosion resistance of plasma nitrided ASTM F138 stainless steel in chloride solution

    International Nuclear Information System (INIS)

    Souza, S.D. de; Olzon-Dionysio, M.; Basso, R.L.O.; Souza, S. de

    2010-01-01

    Plasma nitriding of ASTM F138 stainless steel samples has been carried out using dc glow discharge under 80% H 2 -20% N 2 gas mixture, at 673 K, and 2, 4, and 7 h time intervals, in order to investigate the influence of treatment time on the microstructure and the corrosion resistance properties. The samples were characterized by scanning electron microscopy, glancing angle X-ray diffraction and conversion electron Moessbauer spectroscopy, besides electrochemical tests in NaCl aerated solution. A modified layer of about 6 μm was observed for all the nitrided samples, independent of nitriding time. The X-ray diffraction analysis shows broad γ N phase peaks, signifying a great degree of nitrogen supersaturation. Besides γ N, the Moessbauer spectroscopy results indicated the occurrence of γ' and ε phases, as well as some other less important phases. Corrosion measurements demonstrate that the plasma nitriding time affects the corrosion resistance and the best performance is reached at 4 h treatment. It seems that the ε/γ' fraction ratio plays an important role on the resistance corrosion. Additionally, the Moessbauer spectroscopy was decisive in this study, since it was able to identify and quantify the iron phases that influence the corrosion resistance of plasma nitrided ASTM F138 samples.

  7. Iron oxides characterization by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Basurto Sanchez, R.

    1993-01-01

    In this work rust development on low carbon wire surface after the conformation process at different temperatures was studied by Moessbauer spectroscopy. The characterization was made by determining the following spectral parameters; 1) Quadrupole splitting, 2) Isomer shift, and 3) Magnetic splitting. The area quantification determined the percentage amount of three different iron oxides. These iron oxides were: a) Wustite (Fe O), b) Hematite (Fe 2 O 3 ), and c) Magnetite (Fe 3 O 4 ) which were present in the rust studied. With the results it was possible to establish the best temperature to favor the development of each of these iron oxides. (Author)

  8. Spin dynamics study of magnetic molecular clusters by means of Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Cianchi, L.; Del Giallo, F.; Spina, G.; Reiff, W.; Caneschi, A.

    2002-01-01

    Spin dynamics of the two magnetic molecular clusters Fe4 and Fe8, with four and eight Fe(III) ions, respectively, was studied by means of Moessbauer spectroscopy. The transition probabilities W's between the spin states of the ground multiplet were obtained from the fitting of the spectra. For the Fe4 cluster we found that, in the range from 1.38 to 77 K, the trend of W's versus the temperature corresponds to an Orbach's process involving an excited state with energy of about 160 K. For the Fe8, which, due to the presence of a low-energy excited state, could not be studied at temperatures greater than 20 K, the trend of W's in the range from 4 to 18 K seems to correspond to a direct process. The correlation functions of the magnetization were then calculated in terms of the W's. They have an exponential trend for the Fe4 cluster, while a small oscillating component is also present for the Fe8 cluster. For the first of the clusters, τ vs T (τ is the decay time of the magnetization) has a trend which, at low temperatures (T 15 K, τ follows the trend of W -1 . For the Fe8, τ follows an Arrhenius law, but with a prefactor which is smaller than the one obtained susceptibility measurements

  9. Multiwire proportional chamber for Moessbauer spectroscopy: development and results

    International Nuclear Information System (INIS)

    Costa, M.S. da.

    1985-12-01

    A new Multiwere proportional Chamber designed for Moessbauer Spectroscopy is presented. This detector allows transmission backscattering experiments using either photons or electrons. The Moessbauer data acquisition system, partially developed for this work is described. A simple method for determining the frontier between true proportional and semi-proportional regions of operation in gaseous detectors is proposed. The study of the tertiary gas mixture He-Ar-CH 4 leads to a straight forward way of energy calibration of the electron spectra. Moessbauer spectra using Fe-57 source are presented. In particular those obtained with backsattered electrons show the feasibility of depth selective analysis with gaseous proportional counters. (author) [pt

  10. Moessbauer Spectroscopy Studies of Some Intermetallics in the Zr-Nb-Fe System

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C. [CNEA-UNSAM, Comision Nacional de Energia Atomica, Instituto de Tecnologia J. Sabato (Argentina); Saragovi, C. [Comision Nacional de Energia Atomica, Departamento de Fisica (Argentina); Granovsky, M.; Arias, D. [Comision Nacional de Energia Atomica, Departamento de Materiales (Argentina)

    2002-03-15

    Samples with the following compositions: Zr{sub 62}Nb{sub 14}Fe{sub 24}, Zr{sub 65}Nb{sub 10}Fe{sub 25} and Zr{sub 52}Nb{sub 10}Fe{sub 38} were studied by Moessbauer spectroscopy. All of them showed a ternary cubic Ti{sub 2}Ni-type phase (QS: 0.30{+-}0.02, IS: -0.14{+-}0.01) and traces of Zr{sub 2}Fe phase (QS: 0.86{+-}0.03, IS: -0.29{+-}0.01). Zr{beta} phase (QS: 0.22{+-}0.01, IS: -0.11{+-}0.01) was also detected except in the case of the richer Fe sample. In addition to these expected phases, a hexagonal MgZn{sub 2}-type phase was determined. The assigned parameters for this phase are: QS: 0.38{+-}0.04, IS: -0.28{+-}0.02. These results suggest a revision of the diagram.

  11. Study of the structural modifications in activated clays by Moessbauer spectroscopy and X-ray diffractometry

    Energy Technology Data Exchange (ETDEWEB)

    Huaypar, Yezena, E-mail: yhuaypar@yahoo.es; Bravo, Jorge, E-mail: jbravoc@unmsm.edu.pe [Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Fisicas (Peru); Gutarra, Abel; Gabriel, Erika [Universidad Nacional de Ingenieria, Facultad de Ciencias (Peru)

    2007-02-15

    In this work we study the changes induced on the structure of a smectite clay by chemical acid activation with HCl using X-ray diffractometry (XRD) and transmission Moessbauer spectroscopy (TMS) techniques. By XRD we were able to determine the mineralogical composition of the clay samples and measure the changes in the interplanar distance associated to the structural modifications in the clays. We measured a reduction in the interplanar distance and reflection intensity as the acid concentration in the activation process increased. TMS allowed us identify and characterize the structural sites occupied by ferric and ferrous iron cations. In addition, we were able to monitor the effects caused by the chemical acid activation on the valence state of the iron cations that occupy these structural sites in the clay. For the treatment at low acid concentration, keeping time and temperature of activation constant, our results showed a strong effect on the ferrous and ferric iron sites, reducing and increasing their adsorption relative areas respectively.

  12. Study of the structural modifications in activated clays by Moessbauer spectroscopy and X-ray diffractometry

    International Nuclear Information System (INIS)

    Huaypar, Yezena; Bravo, Jorge; Gutarra, Abel; Gabriel, Erika

    2007-01-01

    In this work we study the changes induced on the structure of a smectite clay by chemical acid activation with HCl using X-ray diffractometry (XRD) and transmission Moessbauer spectroscopy (TMS) techniques. By XRD we were able to determine the mineralogical composition of the clay samples and measure the changes in the interplanar distance associated to the structural modifications in the clays. We measured a reduction in the interplanar distance and reflection intensity as the acid concentration in the activation process increased. TMS allowed us identify and characterize the structural sites occupied by ferric and ferrous iron cations. In addition, we were able to monitor the effects caused by the chemical acid activation on the valence state of the iron cations that occupy these structural sites in the clay. For the treatment at low acid concentration, keeping time and temperature of activation constant, our results showed a strong effect on the ferrous and ferric iron sites, reducing and increasing their adsorption relative areas respectively.

  13. Study of electron transmission through thin metallic films by the electron moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Babikova, Yu.F.; Vakar, O.M.; Gruzin, O.M.; Petrikin, Yu.V.

    1983-01-01

    Results of the experimental study of the transmission of conversion electrons through aluminium, iron, tin and gold films are presented. Absorption of resonance electrons of the Moessbauer nuclide 57 Fe, formed during target irradiation with γ-quanta of 57 Co source in chromium matrix has been studied. It is asserted that absorption of conversion electrons in films of different elements is similar; at that, like in the case of β-particles, the law of absorption of resonance electrons, emitted from the flat layer, is exponential For conversion electrons of the Moessbauer nuclide 57 Fe the absorption coefficient is (0.025+-0.002) cm 2 /μg, which in the case of iron absorbing film corresponds to (20.0+-1.0)x10 4 cm -1

  14. In situ 119Sn Moessbauer spectroscopy used to study lithium insertion in c-Mg2Sn

    International Nuclear Information System (INIS)

    Aldon, L.; Ionica, C. M.; Lippens, P. E.; Larcher, D.; Tarascon, J.-M.; Olivier-Fourcade, J.; Jumas, J.-C.

    2006-01-01

    The electrochemical reactions of Li with c-Mg 2 Sn have been investigated by in situ Moessbauer spectroscopy of 119 Sn and X-ray diffraction. The lithiation transforms initially c-Mg 2 Sn part into Li x Mg 2 Sn alloy (x 2 MgSn ternary alloy. In situ Moessbauer spectroscopy provides valuable information on local environment of tin and swelling behavior and cracking of the particles during discharge and charge processes.

  15. Moessbauer spectroscopy of metals from birth to death

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Francisco Eiichi [Osaka University (Japan)

    1998-12-15

    In today's metallurgy, precision techniques, such as X-ray and electron diffraction, electron microscopy, infrared spectroscopy and electron probe micro-analyzer, are being indispensably used, and, comparing to them, Moessbauer spectroscopy is not inferior at all in usefulness, convenience and cost benefit. Actually, however, it is not yet popular among the metallurgists probably because people believe that the Moessbauer effect is a difficult physics, radioactive sources are difficult to handle, and spectral analyses are complicated. These beliefs are in fact groundless and must be dissolved for further diffusion of this useful Moessbauer technique in metals and other industries.The present introductory talk intends to help people's better understanding and no anxiety for using the Moessbauer spectroscopy by showing how it can be applied to various problems of metals and alloys from their birth to the end, that is, from the study of minerals and ores before smelting to that of corrosion and other failures.Firstly, the principle of Moessbauer spectroscopy will be explained with simplest illustrations together with simple pictures of apparatuses including the high temperature furnace and the high pressure cell.In the second will be shown typical examples of Moessbauer patterns of magnetite, carbon steel and other alloys, with indications of how to analyze the seemingly complicated spectra. Some other examples will be shown with special apparatuses easy to measure. The usefulness and convenience of Moessbauer spectroscopy will be understood again from these examples. More examples will be on amorphous alloys and other advanced materials.

  16. Moessbauer Spectroscopy: Elegance and versatility in chemical diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Guetlich, Philipp; Garcia, Yann, E-mail: guetlich@uni-mainz.d [Unite de Chimie des Materiaux Inorganiques et Organiques, Departement de Chimie, Universite Catholique de Louvain, Place L. Pasteur 1, 1348 Louvain la Neuve (Belgium)

    2010-03-01

    Dedicated to Professor Rudolf Ludwig Moessbauer on the occasion of his 80th birthday. Soon after the discovery of the recoilless nuclear resonance fluorescence by Rudolf L. Moessbauer some fifty years ago a new spectroscopic technique developed quickly on the basis of this resonance phenomenon as an excellent tool for the investigation of materials through electric and magnetic hyperfine interactions between electrons and suitable Moessbauer nu-clides. Many disciplines of solid state research have benefited from applications of the new tool for non-destructive phase analysis. Chemists in particular have recognized the information that can be derived from Moessbauer spectra regarding oxidation and spin state, molecular symmetry, bonding properties, magnetism, dynamic phenomena such as spin state switching, electronic transfer processes and other phase fluctuations to name a few. This Keynote Lecture presents highlights of chemical applications of Moessbauer spectroscopy selected from work during the past five decades which will demonstrate the elegance and versatility of the technique in the hands of (not only) chemists, but materials scientists in the broadest sense. The retrospect begins with studies in the early sixties on simple oxides and coordination compounds, where Moessbauer spectroscopy played a decisive role in solving unanswered questions, and concludes with fascinating current discoveries on the Planet Mars and most recent developments in the use of synchrotron radiation for nuclear resonance scattering (NFS, NIS).

  17. 57Fe Moessbauer studies on natural chromites

    International Nuclear Information System (INIS)

    Das, D.; Sudarshan, M.; Chintalapudi, S.N.; Chakravorty, K.L.

    1996-01-01

    Five chromite samples procured from two different belts of India have been studied by 57 Fe Moessbauer spectroscopy. It is shown that four symmetric doublets are sufficient to fit the chromite spectrum; the Moessbauer parameters and Fe 3+ /Fe 2+ ratio are computed. For fully oxidized chromite with only Fe 3+ , two doublets are needed and the parameters are computed. (author). 19 refs., 4 figs., 4 tabs

  18. Moessbauer spectroscopy and X-ray diffraction study of 304 L stainless steel thin films

    International Nuclear Information System (INIS)

    Boubeker, B.; Eymery, J.P.; Goudeau, P.; Sayouty, E.H.

    1994-01-01

    304 L stainless steel films (SS) were elaborated using an ion-beam sputtering technique. The target material was a sheet of commercial grade 304 L SS. The starting material was first analysed by both conversion electron Moessbauer spectroscopy (CEMS) and X-ray diffraction. The nonmagnetic state and f.c.c. structure of this material were confirmed. The films were deposited on various substrates with thicknesses in the 175-800 nm range. The films are found to have both b.c.c. structure and ferromagnetic character. X-ray diffraction technique was also used in order to determine the residual stresses developed during the deposition process. The second stage of the work is devoted to the evolution of the film structure as a function of annealing treatments. So isochronal and isothermal kinetics at temperatures higher than 913 K have allowed to follow the alpha --> gamma phase transformation using X-ray diffraction and CEMS technique.The X-ray diffractograms reveal the existence of both b.c.c. and f.c.c. phases. Similar results can be deduced from Moessbauer spectra due to the single line coming from the non-magnetic phase and the sextet coming from the ferromagnetic phase. In addition the CEMS spectra reveal that the ferromagnetic component is split into two parts which indicates the existence of two iron sites. 1 fig., 4 refs.(author)

  19. Analysis of biological tissues by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bonkova, I.; Bujdos, M.; Miglierini, M.

    2016-01-01

    The aim of this work was to analyze of biological tissues by Moessbauer spectroscopy in terms of demonstration of the magnetic properties of iron and its structural positions. Lyophilized samples of the human brain, human and equine spleen were used for the analysis. The samples were measured with 57 Fe Moessbauer spectroscopy in transmission arrangement at room temperature (∼ 300 K) and at a temperature of liquid helium (4.2 K). The resulting Moessbauer spectra measured at room temperature had doublet character, which confirms the presence of non-magnetic particles. On the contrary, low-temperature measurements are a superposition of several sextet and one duplicate. Hyperfine parameters obtained are similar to those reported hematite, ferrihydrite or magnetite. (authors)

  20. Systematic study of hyperfine fields in Rh2 Y Z type Heusler alloys with 119 Sn impurity using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ramos, S.M.M.

    1985-01-01

    The magnetic hyperfine fields in the Heusler alloys Rh 2 Mn .98 Ge Sn 02 , Rh 2 Mn Ge .98 Sn .02 , Rh 2 Mn Pb .98 Sn .02 and Rh 2 Mn Sn has been studied by 119 Sn Moessbauer spectroscopy at 293 K, 77 K, 4.2 K and 293 K with applied external magnetic field. The results show that when one compare the magnetic hyperfine fields systematic with the Heusler alloys X 2 Mn Z (X = Co, Ni, Cu, Pd, and Z = s p metal), this systematic is similar to the Co alloys, although can not explained by the currents models for the Heusler alloys. (author)

  1. Hydrogenation of FeCoZr-Al{sub 2}O{sub 3} nanocomposites studied by Moessbauer spectroscopy and magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Saad, A. [Al-Balqa Applied University, Appl. Science Department (Jordan); Kasiuk, J.; Fedotova, J., E-mail: Julia@hep.by [NC PHEP BSU (Belarus); Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics (Hungary); Przewoznik, J.; Kapusta, Cz. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science (Poland); Marszalek, M. [Niewodniczanski Institute of Nuclear Physics PAN (Poland)

    2009-02-15

    Hydrogenation effects on crystalline and magnetic structure of nanocomposites (FeCoZr){sub x}(Al{sub 2}O{sub 3}){sub 100-x}, 38 {<=} x {<=} 63 at.% are studied by {sup 57}Fe Moessbauer spectroscopy and magnetometry. Variations of local structure, blocking temperature and mean FeCoZr nanoparticles' volume are discussed with respect to (i) composition and (ii) two competing processes-H{sub 2} incorporation and annealing-occurred during treatment in H{sub 2} plasma.

  2. Moessbauer studies of malaria

    International Nuclear Information System (INIS)

    Bauminger, E.R.; Ofer, S.; Ginsburg, H.; Yayon, A.

    1983-01-01

    Moessbauer studies of rat and human erythrocytes infected by malarial parasites have been carried out. Different parameters of the pigment iron were obtained in human and rat infected red blood cells. No difference was found between the parameters obtained in rat erythrocytes infected by drug sensitive and drug resistant strains of P. berghei, both before and after the treatment with chloroquine. The pigment was shown to contain a trivalent, high spin iron compound, which is different from hematin. (Auth.)

  3. A study of the local structure around Eu3+ ions in oxide glasses using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Todoroki, S.; Hirao, K.; Soga, N.

    1993-01-01

    The local structure around Eu 3+ ions in several oxide glasses (silicate, germanate and borophosphate glasses) was investigated by using 151 Eu Moessbauer spectroscopy. It was found that the isomer shift (IS) of silicate and borophosphate glasses was independent of the sodium content, but that of germanate glasses was not. This means the first coordination sphere around Eu 3+ ions in silicate glasses is insensitive to the composition of the glass matrix. It is assumed that, regardless of the sodium content, Eu 3+ ions in silicate glasses attract a certain amount of nonbridging oxygen (NBO, Si-O direct difference ) when incorporated stably into silicate glass matrix, because NBO is the only species donating negative charge. For germanate glasses, the behavior of IS is considered to be related to the resence of GeO 6/2 octahedra. On the basis of experimental results, the coordination models of Eu 3+ in these systems are proposed. (orig.)

  4. Influence of preparation conditions on precipitated iron oxides and hydroxides: a Moessbauer spectroscopy study

    International Nuclear Information System (INIS)

    Dlamini, H.; Pollak, H.; Coville, N.J.; Van Wyk, J.A.

    1999-01-01

    A mixture of hematite and an amorphous Fe(III) hydroxide species are formed during the preparation of precipitated iron based catalysts. The percentage of the two phases varies with the change in the preparation conditions. Moessbauer spectroscopy reveals that maximum hematite was formed between pH 6-7 and C Fe3+ /C Na2CO3 of 0.33-0.375 corresponding to an increase in product crystallinity as determined from XRD line broadening analysis. The change in the product distribution with preparation conditions suggests the presence of two competing reactions. Particle size distribution of the hematite phase indicates that nucleation and particle growth occur at the same time. (author)

  5. Moessbauer spectroscopy of iron in clay minerals

    International Nuclear Information System (INIS)

    Raclavsky, K.; Sitek, J.; Lipka, J.

    1975-01-01

    Selected pure clay minerals predominantly of Czechoslovak origin were studied, such as montmorillonite, nontronite, beidellite, glauconite, seladonite, illite, vermiculite, saponite, palygorskite, goethite. Moessbauer measurements were performed at room temperature with a 57 Co in Pd source. The spectra were fitted by the least square method. The parameters of the measured Moessbauer spectra are given. The values of isomer shifts, quadrupole splittings and line widths were obtained with an error of +- 0.03 mm/sec. (Z.S.)

  6. Application of Moessbauer spectroscopy to the study of tannins inhibition of iron and steel corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.pa [Universidad de Panama, CITEN, Depto. de Quimica Fisica (Panama); Obaldia, J. De; Rodriguez, M. V. [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2011-11-15

    The inhibitory effect of tannins was investigated using, among others, potentiodynamic polarizations and Moessbauer spectroscopy. These techniques confirmed that the nature, pH and concentration of tannic solution are of upmost importance in the inhibitory properties of the solutions. It is observed that at low tannin concentration or pH, both, hydrolizable and condensed tannins, effectively inhibit iron corrosion, due to the redox properties of tannins. At pH Almost-Equal-To 0, Moessbauer spectra of the frozen aqueous solutions of iron(III) with the tannin solutions showed that iron is in the form of a monomeric species [Fe(H{sub 2}O){sub 6}]{sup 3 + }, without coordination with the functional hydroxyl groups of the tannins. The suspended material consisted of amorphous ferric oxide and oxyhydroxides, though with quebracho tannin partly resulted in complex formation and in an iron (II) species from a redox process. Other tannins, such as chestnut hydrolysable tannins, do not complex iron at this low pH. Tannins react at high concentrations or pH (3 and 5) to form insoluble blue-black amorphous complexes of mono-and bis-type tannate complexes, with a relative amount of the bis-ferric tannate generally increasing with pH. Some Fe{sup 2 + } in the form of hydrated polymeric ferrous tannate could be obtained. At pH 7, a partially hydrolyzed ferric tannate complex was also formed. The latter two phases do not provide corrosion protection. Tannin solutions at natural pH react with electrodeposited iron films (approx. 6 {mu}m) to obtain products consisting only on the catecholate mono-complex of ferric tannate. Some aspects of the mechanism of tannins protection against corrosion are discussed.

  7. 57Fe Moessbauer Spectroscopy Studies of Meteorites: Implications for Weathering Rates, Meteorite Flux, and Early Solar System Processes

    International Nuclear Information System (INIS)

    Bland, P. A.; Berry, F. J.; Jull, A. J. T.; Smith, T. B.; Bevan, A. W. R.; Cadogan, J. M.; Sexton, A. S.; Franchi, L. A.; Pillinger, C. T.

    2002-01-01

    Ordinary chondrite finds, terrestrial age dated using 14 C analyses, from different meteorite accumulation sites, have been examined by Moessbauer spectroscopy to quantitatively determine terrestrial oxidation. We observe differences in weathering rates between sites, and also between different chondrite groups. A comparison of weathering over time, and its effect in 'eroding' meteorites, together with the number and mass distribution of meteorites in each region, enables us to derive estimates of the number of meteorite falls over a given mass per year. Studies of how the oxygen isotopic composition of samples varies with weathering indicate that incipient alteration may occur without a pronounced isotopic effect, possibly due to weathering of silicates to topotactically oriented smectite confined spaces where the water volume is limited. This finding has profound implications for the use of oxygen isotopes as a tool in understanding water-rock interaction. It also may reconcile previously contradictory data regarding the nebular or asteroidal location of pre-terrestrial aqueous alteration. Finally, Moessbauer spectroscopy is also found to be a useful tool in determining mineral abundance in carbonaceous chondrites, where a fine-grained matrix makes traditional approaches inapplicable. Again, the results have implications for the modification of chondritic materials in the early solar system.

  8. 57Fe Moessbauer spectroscopic studies on photosensitive nitrile hydratase (NHase)

    International Nuclear Information System (INIS)

    Kobayashi, Yoshio; Odaka, Masafumi

    2001-01-01

    57 Fe Moessbauer spectroscopy is a very useful technique for elucidating the chemical properties and biological changes of Fe species located at the reaction centers in various biological systems. We have applied 57 Fe Moessbauer spectroscopy to study the mechanism of photoactivation and the structural change caused by light irradiation of nitrile hydratase (NHase). (author)

  9. Moessbauer spectroscopy in neptunium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Tadahiro; Nakada, Masami; Masaki, Nobuyuki; Saeki, Masakatsu [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1997-03-01

    Moessbauer effects are observable in seven elements of actinides from {sup 232}Th to {sup 247}Cm and Moesbauer spectra have been investigated mainly with {sup 237}Np and {sup 238}U for the reasons of availability and cost of materials. This report describes the fundamental characteristics of Moessbauer spectra of {sup 237}Np and the correlation between the isomer shift and the coordination number of Np(V) compounds. The isomer shifts of Np(V) compounds had a tendency to increase as an increase of coordination number and the isomer shifts of Np(V) compounds showed broad distribution as well as those of Np(VI) but {delta} values of the compounds with the same coordination number were distributed in a narrow range. The {delta} values of Np(VI) complexes with O{sub x} donor set suggest that the Np atom in its hydroxide (NpO{sub 2}(OH){center_dot}4H{sub 2}O)might have pentagonal bipyramidal structure and at least, pentagonal and hexagonal bipyramidal structures might coexist in its acetate and benzoate. Really, such coexistence has been demonstrated in its nitrate, (NpO{sub 2}){sub 2}(NO{sub 3}){sub 2}{center_dot}5H{sub 2}O. (M.N.)

  10. High-pressure phases of CuI studied by 129I-Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Kaindl, G.; Nowik, I.; Frank, K.H.

    1992-01-01

    The results of an 129 I-Moessbauer study of the high-pressure phases of CuI at 4.2 K and for external pressures up to 71 kbar are reported. The isomer shift S and the electric quadrupole interaction E q are found to undergo large discontinuities at the crystallographic phase-transition pressures of ≅18 kbar from zinc-blende to rhombohedral structure and at ≅46 kbar from rhombohedral to tetragonal. The pressure coefficients of these hyperfine parameters are significantly different for the three phases (zinc-blende; rhombohedral; tetragonal): dS/dP=-3.3; =+1.5; =+2.5x10 -3 mm/s/kbar. These results cannot be explained in terms of a simple molecular-orbital picture; instead, they reflect pressure-induced variations of the halogen-p/metal-d hybridization in the valence bands of the various phases of CuI. (orig.)

  11. Studies of iron in deep-sea sediments by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Drodt, M.; Lougear, A.; Trautwein, A.X.; Koenig, I.; Suess, E.; Koch, C. Bender

    1998-01-01

    The distribution of the forms of Fe in the solid phases in core samples of sediments from the Peru Basin has been investigated by Moessbauer spectroscopy with special attention to the cause of the sharp color transition between an upper green colored and a lower tan colored part. An important part of sample handling includes strict exclusion of oxygen during preparation of absorbers and measurements at cryogenic temperatures. The measurement strategy includes measurements between 77 K and 300 mK in zero external magnetic field, supplemented by measurements in external magnetic fields at 4.2 and 300 mK (up to 6.2 and 1 T, respectively). The temperature scans allow detection, identification and quantification of superparamagnetic iron oxides (goethite and hematite). The oxides are only present in samples from the upper tan-colored part of the core. The major part of the Fe(II) and Fe(III) (>80%) is present in a magnetic structure similar to that of layer silicates. The relative Fe(II) content of the layer silicates is practically identical to that determined from the paramagnetic components measured at liquid nitrogen temperature. This shows that the color transition in the sediment coincides with a change in the relative Fe(II) content in layer silicates from 11 to 37%. The color change can thus be explained by an increase in occurrence of Fe(II)-Fe(III) pairs exhibiting absorption bands due to intervalence electron transfer

  12. The metallurgic furnaces at the Curamba Inca site (Peru): a study by Moessbauer spectroscopy and X-ray diffractometry

    International Nuclear Information System (INIS)

    Huaypar, Yezena; Vetter, Luisa; Bravo, Jorge

    2007-01-01

    The Inca site at Curamba is located in the Province of Apurimac in the southern highlands of Peru where, according to some historians, several thousand furnaces used for ore smelting were found. For this work, four samples of burned soil were gathered from these furnaces and classified as Curamba1, Curamba2, Curamba3, and Curamba4, and studied using transmission Moessbauer spectroscopy (TMS) and X-ray diffractometry (XRD). The mineralogical composition of the samples was determined by XRD and the structural sites in the minerals occupied by iron cations were characterized by TMS. Moreover, an attempt was made to determine the maximum temperature reached in these furnaces using the refiring technique of the samples in an oxidizing environment and monitoring the structural modifications at the iron sites by changes in the Moessbauer hyperfine parameters. The TMS results of Curamba2 show that the maximum temperature reached in this furnace was about 900 deg. C, in agreement with the mineralogical composition found by XRD. In the case of Curamba1 and Curamba4 the maximum temperature estimated was about 400 deg. C.

  13. Chemical aspects of 237 Np Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Karraker, D.G.

    1984-01-01

    The 237 Np Moessbauer effect has been especially useful in studies of neptunium chemistry, by virtue of its excellent resolution and straightforward experimental techniques. Neptunium can have valences from +3 to +7, and a broad range of compounds can be prepared that are analogous to those of other actinide elements. Studies on neptunium compounds, for example, have a ready application to the analogous compounds of uranium and plutonium. The emphasis in this paper will be on the application of the 237 Np Moessbauer effect to problems in neptunium chemistry

  14. Thermal treatment of the Fe78Si9B13 alloy in it amorphous phase studied by means of Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Cabral P, A.; Lopez, A.; Garcia S, F.

    2003-01-01

    The magnetic and microhardness changes, dependents of the temperature that occur in the Fe 78 Si 9 B 13 alloy in it amorphous state were studied by means of the Moessbauer spectroscopy and Vickers microhardness. According to the Moessbauer parameters and in particular that of the hyperfine magnetic field, this it changes according to the changes of the microhardness; i.e. if the microhardness increases, the hyperfine magnetic field increases. The registered increment of hardness in the amorphous state of this alloy should be considered as anomalous, according to the prediction of the Hall-Petch equation, the one that relates negative slopes with grain sizes every time but small. (Author)

  15. Studies on the condition of obtaining a single phase superconducting Nb/sub 3/Sn layer by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B [Politechnika Wroclawska (Poland); Chojcan, J [Wroclaw Univ. (Poland)

    1983-11-16

    The /sup 119/Sn Moessbauer spectroscopy was used to examine the influence of temperature (1153 to 1253 K) and heating time (11 and 22 min) on the formation of the ..beta..-Nb/sub 3/Sn phase in simultaneous processes: peritectic reaction of NbSn/sub 2/ phase decomposition and reactive diffusion of Sn atoms into the Nb1.5%Zr base.

  16. Formation of the 1:2:3 structure in Y-Ba-Cu(Fe)-O system studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Valko, P.; Miglierini, M.; Sitek, J.; Hucl, M.; Gruskova, A.

    1990-01-01

    Annealing time and temperature dependence of Y, Ba, Cu, Fe nitrade mixture towards new phases creation was revealed by Moessbauer spectroscopy. The observed changes can be assigned to chemical decomposition of corresponding nitrades and creation of intermedial and final Y 1 Ba 2 (Cu 0.95 Fe 0.05 ) 3 O x phase. (orig.)

  17. Study of irradiated F82H steel and its model Fe-Cr alloy by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Huang, S.S.; Kitao, S.; Xu, Q.; Sato, K.; Yoshiie, T.

    2013-01-01

    In this work, Moessbauer spectroscopy which is a super-precision tool was conducted on F82H and its model Fe-Cr alloys before and after irradiation to take a further look on the interaction between carbides and point defects and Cr effect on microstructural evolution during irradiation in void incubation period. (J.P.N.)

  18. Moessbauer spectroscopy as a tool in astrobiology

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Christian, E-mail: schroedc@uni-mainz.de; Klingelhoefer, Goestar, E-mail: klingel@mail.uni-mainz.de [Johannes Gutenberg-Universitaet, Institut fuer Anorganische Chemie und Analytische Chemie (Germany); Bailey, Brad E., E-mail: bebailey@ucsd.edu; Staudigel, Hubert, E-mail: hstaudigel@ucsd.edu [University of California San Diego, Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography (United States)

    2005-11-15

    Two miniaturized Moessbauer spectrometers are part of the Athena instrument package of the NASA Mars Exploration Rovers, Spirit and Opportunity. The primary objectives of their science investigation are to explore two sites on the surface of Mars where water may once have been present, and to assess past environmental conditions at those sites and their suitability for life. Aqueous minerals - jarosite at Meridiani Planum, Opportunity's landing site, and goethite in the Columbia Hills in Gusev Crater, Spirit's landing site - were identified by Moessbauer spectroscopy, thus providing in situ proof of water being present at those sites in the past. The formation of jarosite in particular puts strong constraints on environmental conditions during the time of formation and hence on the evaluation of potential habitability. On Earth Moessbauer spectroscopy was used to investigate microbially induced changes in Fe oxidation states and mineralogy at the Loihi deep sea mount, a hydrothermal vent system, which might serve as an analogue for potential habitats in the Martian subsurface and the sub-ice ocean of Jupiter's icy moon Europa.

  19. Moessbauer spectroscopy as a tool in astrobiology

    International Nuclear Information System (INIS)

    Schroeder, Christian; Klingelhoefer, Goestar; Bailey, Brad E.; Staudigel, Hubert

    2005-01-01

    Two miniaturized Moessbauer spectrometers are part of the Athena instrument package of the NASA Mars Exploration Rovers, Spirit and Opportunity. The primary objectives of their science investigation are to explore two sites on the surface of Mars where water may once have been present, and to assess past environmental conditions at those sites and their suitability for life. Aqueous minerals - jarosite at Meridiani Planum, Opportunity's landing site, and goethite in the Columbia Hills in Gusev Crater, Spirit's landing site - were identified by Moessbauer spectroscopy, thus providing in situ proof of water being present at those sites in the past. The formation of jarosite in particular puts strong constraints on environmental conditions during the time of formation and hence on the evaluation of potential habitability. On Earth Moessbauer spectroscopy was used to investigate microbially induced changes in Fe oxidation states and mineralogy at the Loihi deep sea mount, a hydrothermal vent system, which might serve as an analogue for potential habitats in the Martian subsurface and the sub-ice ocean of Jupiter's icy moon Europa.

  20. Moessbauer spectroscopy and nuclear inelastic scattering studies on polynuclear oxo-bridged iron catalyst-first results

    International Nuclear Information System (INIS)

    Rajagopalan, S.; Asthalter, T.; Rabe, V.; Buerck, U. van; Wagner, F. E.; Laschat, S.

    2008-01-01

    Polynuclear iron catalysts are interesting materials because of their novel properties. In the future they may help to replace high cost and hazardous heavy metal catalysts by efficient, non toxic and economic iron compounds. In this work, we present some preliminary results on a novel polynuclear oxo-bridged iron catalyst. The chemical environment of the metal species (Fe) was studied under Gif-type conditions (Fe catalyst/Zn/O 2 in pyridine/acetic acid) with cyclohexene as substrate. Such Gif-type catalysts are able to catalyse the selective oxidation of alkanes and alkenes. The characterization was done by Moessbauer spectroscopy and nuclear inelastic scattering. In order to identify the intermediate species during the reaction (selective oxidation using molecular O 2 ), a freeze-quench technique was used. This also helps to understand the kinetics of the chemical reaction.

  1. Structural and lattice dynamics studies of microcrystals by means of the Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Pasternak, M.

    1978-05-01

    Moessbauer studies on 129 I, 57 Fe and 119 Sn were conducted in several disordered and microscopic systems in order to investigate properties of lattice dynamics, chemical bonding and phase transitions. The project included the following studies: (1) Granular crystals of Sn embedded in tin-oxide matrix; the nature of the superconductivity transition of very small grains of tin was investigated. (2) Lattice dynamics and characterization of amorphous tin oxide obtained by condensing atoms of Sn and O 2 gas on a 77 K substrate. The hyperfine interaction and the temperature dependence of the Debye-Waller factor were essential to determine the structure of the amorphous tin oxide. (3) The nature of the chemical bond of the alkaly halides ionic crystals and molecules; molecules of Li, Na, K, Rb and Cs iodides were trapped in agron matrices, and the isomer-shift values were obtained from absorption spectra. (4) Binding of single iron and tin atoms to CH 4 , NH 3 , H 2 and C 6 H 6 molecules, with samples at low temperatures between 2 and 77 K; conclusions were derived regarding the cryochemistry of these systems, as related to fundamental problems of catalysis, chemisorption and ''cracking'' of organic molecules

  2. Moessbauer spectroscopy of the Soledade meteorite

    International Nuclear Information System (INIS)

    Paduani, Clederson; Peres, Carlos Ariel Samudio

    2004-01-01

    Full text: Since the early studies of the microstructure and chemical composition of meteorites the formation of magnetic phases have attracted the attention of metallurgists. Mostly metallic specimens presented high contents of nickel and iron as major constituents, and thus the Fe-Ni alloys formed under such special conditions have been the subject of several investigations with a variety of experimental techniques. This is not an easy task considering the weathering process and the distribution of oxides in the metallic matrix, which in some cases varies in composition from one region to another. In this work we applied the Moessbauer spectroscopy to study the iron-bearing phases detected in the meteorite called Soledade. Although no one knows precisely who and when this specimen was found, it received the name of the locality from where it proceeded near the city of Passo Fundo in the state of Rio Grande do Sul in Brazil. The first studies indicate that this metallic meteorite is an octahedrite, with polycrystalline troilite, cohenite, schreibersite and rhabdites as major constituents. It consists of a solid block weighing 68 kg, with an irregular form measuring about 36x22x16 cm. (author)

  3. Irradiation effects detected by Moessbauer spectroscopy in iron complexes

    International Nuclear Information System (INIS)

    Ladriere, J.

    1998-01-01

    The nature and the extent of the 60 Co gamma radiolysis of several iron coordination compounds have been analysed by Moessbauer absorption spectroscopy. The comparison of the radiolytic yields with the after effects observed by Moessbauer emission spectroscopy in similar 57 Co-doped compounds, supports the self-radiolysis model

  4. Moessbauer study of hydrated iron sulfates

    International Nuclear Information System (INIS)

    Araujo, S.I.; Danon, J.; Iannarella, L.

    1991-01-01

    The hydrated iron sulfates amarantite Fe(SO sub(4))(OH).3H sub(2)O, copiapite (Mg,Al)Fe sup(3+) sub(4)(SO sub(4)) sub(6)(OH) sub(2).20H sub(2)O and ungemachite K sub(3)Na sub(9)Fe(SO sub(4)) sub(6)(OH) sub(3).9H sub(2)O were studied by Moessbauer Spectroscopy (MS) in connection with Differential Scanning Calorimetry (DSC). The effect of the dehydration on the hyperfine parameters at the Fe sites was investigated. For amarantite, the Moessbauer spectrum remained practically unchanged, while the Fe sup(3+) quadrupole splittings for copiapite and ungemachite increased. The Fe sup(2+) quadrupole splitting of ungemachite was also unchanged. We have found out the anisotropy of the recoiless absorption probability for the sup(57)Fe Moessbauer gamma ray in amarantite. The three minerals were found to be highly hygroscopic after the dehydration consequent of the DSC measurements. (author)

  5. Moessbauer spectroscopy and X-ray diffraction studies of Fe-Ni order-disorder processes in a 35% Ni meteorite (Santa Catharina)

    International Nuclear Information System (INIS)

    Scorzelli, R.B.; Danon, J.

    1985-01-01

    The composition and structure of iron-nickel alloys in the Santa Catharina iron meteorite were investigated by metallographic techniques, electron microprobe analysis, Moessbauer spectroscopy and X-ray diffraction. The occurence of an ordered Fe-Ni phase with non-cubic symmetry is demonstrated. This phase is present in large proportions in the Santa Catharina meteorite, and has been identified by its asymmetric Moessbauer spectrum, arising from the presence of a quadrupolar splitting superposed on the magnetic hyperfine splitting. The other major Fe-Ni phase in Santa Catharina gives rise to a single line Moessbauer spectrum with no hyperfine components. X-ray diffraction confirms the presence of the Fe-Ni Llo superstructure in this meteorite. Lattice parameter variations with temperature were found to be identical for the meteorite and for electron irradiated Fe-Ni alloys of the sample composition. Detailed Moessbauer spectroscopy studies from room temperature to liquid helium, and in the presence of external magnetic field show the presence of a smaller amount of another ferromagnetic Fe-Ni phase, probably with disordered structure. The destruction of the superstructure in the Santa Catharina meteorite was investigated after heating the samples. Partial ordering seems to coexist with the disordered phase at intermediate annealing temperatures. At higher temperatures the samples are homogeneous and similar to laboratory produced Fe-Ni alloys with 35% Ni. Order-disorder transformations produced by shock waves and by mechanical treatment are also described. (orig.)

  6. Implementation of the Electron conversion Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Hernandez, Torres, D.; Noriega Scull, C.

    1996-01-01

    In the present work has been exposed the principles of the Conversion Moessbauer Electron Spectroscopy and its possibilities of application. Is also described the operation of the parallel plate avalanche detector made at the CEADEN starting from modifications done to the Gancedo's model and is exposed examples of the use of this detector in the characterization of corroded surfaces, with chemical cleaning and in samples of welded joints. The experiences obtained of this work were extended to the National Polytechnic Institute of Mexico where a similar detector, made in our center, was installed there

  7. Backscattering Moessbauer spectroscopy of Martian dust

    International Nuclear Information System (INIS)

    Bertelsen, P.; Madsen, M. B.; Binau, C. S.; Goetz, W.; Gunnlaugsson, H. P.; Hviid, S. F.; Kinch, K. M.; Klingelhoefer, G.; Leer, K.; Madsen, D. E.; Merrison, J.; Olsen, M.; Squyres, S. W.

    2005-01-01

    We report on the determination of the mineralogy of the atmospherically suspended Martian dust particles using backscattering 57 Fe Moessbauer spectroscopy on dust accumulated onto the magnets onboard the Mars Exploration Rovers. The spectra can be interpreted in terms of minerals of igneous origin, and shows only limited, if any, amounts of secondary minerals that may have formed in the presence of liquid water. These findings suggest that the dust has formed in a dry environment over long time in the history of the planet.

  8. Corrosion study of heat exchanger tubes in pressurized water cooled nuclear reactors by conversion electron Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Homonnay, Z.; Kuzmann, E.; Varga, K.; Nemeth, Z.; Szabo, A.; Rado, K.; Schunk, J.; Tilky, P.; Patek, G.

    2005-01-01

    Nuclear energy production tends to return into the focus of interest because of the constantly increasing energy need of the world and the green house effect problems of the strongest competitor oil or gas based power plants. In addition to the construction of new nuclear power plants, lifetime extension of the existing ones is the most cost effective investment in the energy business. However, feasibility and safety issues become very important at this point, and corrosion of the construction materials should be carefully investigated before decision on a potential lifetime extension of a reactor. 57 Fe-Conversion Electron Moessbauer Spectroscopy (CEMS) is a sensitive tool to analyze the phase composition of corrosion products on the surface of stainless steel. The upper ∼300 nm can be investigated due to the penetration range of conversion electrons. The corrosion state of heat exchanger tubes from the four reactor units of the Paks Nuclear Power Plant, Hungary, were analyzed by several methods including CEMS. The primary circuit side of the tubes was studied on selected samples cut out from the heat exchangers during regular maintenance. Cr- and Ni-substituted magnetite, sometimes hematite, amorphous Fe-oxides/oxyhydroxides as well as the signal of bulk austenitic steel of the tubes were detected. The level of Cr- and Ni-substitution in the magnetite phase could be estimated from the Moessbauer spectra. Correlation between earlier decontamination cycles and the corrosion state of the heat exchangers was sought. In combination with other methods, a hybrid structure of the surface oxide layer of several microns was established. It is suggested that previous AP-CITROX decontamination cycles can be responsible for this structure which makes the oxide layer mobile. This mobility may be responsible for unwanted corrosion product transport into the reactor vessel by the primary coolant.

  9. Cu(2) dynamical correlations in YBa2Cu3Ox studied by Moessbauer spectroscopy on substituted 170Yb3+

    International Nuclear Information System (INIS)

    Hodges, J.A.; Bonville, P.; Imbert, P.; Jehanno, G.

    1990-01-01

    Using Moessbauer spectroscopy, we follow the thermal dependence of the fluctuation rate of the Cu(2) internal (molecular) field acting on a 170 Yb 3+ probe diluted at the Y 3+ sites. We use the fluctuations of this field to track the collective fluctuations of the nearest neighbour correlated Cu(2) moments. Results are presented for oxygen levels x = 6.0 and 6.35 and for T ≤ 80K

  10. Study of Sn100-xMnx amorphous system by 119Sn Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Drago, V.

    1986-01-01

    Thin films of Sn 100-x Mn x amorphous alloys with large range of concentrations were procedure by vapor condensation technique on substrates at temperatures near to liquid helium. The magnetic and paramagnetic hyperfine spectra, and the ordering temperatures were measured by 119 Sn Moessbauer effect. The electrical resistivity was used for characterizing the amorphous state. All the measurements were done 'in situ'. A magnetic phase diagram is proposed. (M.C.K.) [pt

  11. Application of Moessbauer spectroscopy in the study of high temperature oxidation of steel

    International Nuclear Information System (INIS)

    Seberini, M.; Volenik, K.

    1975-01-01

    The applicability was tested of etching by solutions of bromine or iodine in methyl alcohol in separating oxide films from substrates to make possible the measurement of absorption spectra. Prior to etching, scattering spectra of oxidized samples had been measured and the results were compared. Oxide films grown under various conditions on low carbon steel CSN 41 1373 were used in the experiment. The Moessbauer absorption spectrum measurement was found to be useful in the quantitative determination of phase composition. (L.O.)

  12. Moessbauer studies on ancient Jizhon plain Temmoku porcelains

    International Nuclear Information System (INIS)

    Yu Zhengfang; Zheng Yufang; Lin Yongqiang

    1994-01-01

    Three kinds of ancient Jizhou plain Temmoku wares and their several ware-making raw materials were studied by means of X-ray diffraction (XRD) and Moessbauer spectroscopy. The firing technique of ancient Jizhou Temmoku porcelains is discussed. (orig.)

  13. FeRu/TiO2 and Fe/TiO2 catalysts after reduction and Fischer-Tropsch synthesis studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Kraan, A.M. van der; Nonnekens, R.C.H.; Niemantsverdriet, J.W.

    1986-01-01

    A series of TiO 2 -supported bimetallic FeRu catalysts with different Fe:Ru ratios (infinity; 10:1; 3:1; 1:1; 1:3) has been studied by means of in situ Moessbauer spectroscopy. The influence of reduction and Fischer-Tropsch synthesis on the state of iron in the FeRu/TiO 2 catalysts is derived. (Auth.)

  14. A Dilute-Limit Heat of Solution of 3d Transition Metals in Iron Studied with 57Fe Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Chojcan, Jan

    2004-01-01

    The room-temperature 57 Fe Moessbauer spectra for binary iron-based solid solutions Fe 1-x D x with D=V, Cr, Mn and Co, were analysed in terms of binding energy E b between two D atoms in the Fe-D system. The extrapolated values of E b for x=0 were used for computation of the dilute-limit heat of solution of D metals in iron. The results were compared with those derived from calorimetric data concerning the heat of formation of the systems mentioned as well as with those resulting from the Miedema's model of alloys. The comparison shows that our Moessbauer spectroscopy findings are in a qualitative agreement with the available calorimetric data and they are at variance with corresponding Miedema's values for Fe-Mn and Fe-Co systems.

  15. Moessbauer spectroscopy and X-ray fluorescence analysis in studies for determinate the sources of several prehispanic objects

    International Nuclear Information System (INIS)

    Arriola S, H.; Ramos R, P.; Castro V, P.; Jimenez R, A.; Flores D, F.; Garcia Moreno C, C.

    1980-01-01

    A study by the Moessbauer effect and X-ray fluorescence analysis of the mexican prehispanic ceramic specimens is presented. Several iron compounds of the ceramics are determined, the different iron compounds indicate different sources of the clays, and different forms of ovens used with them, this compounds are identified by the differents oxidation states of the magnetic iron Fe 3+ , Fe 2+ . (author)

  16. Moessbauer spectroscopy: Methodology and some applications to magnetic materials

    International Nuclear Information System (INIS)

    Sundqvist, T.

    1986-01-01

    The development of a new computer program for analysis of Moessbauer spectra that allows the user to make a detailed simulation of a measured spectrum is described. The program includes several novel computational algorithms as well as extensive treatment of experimental side effects. Data collection instrumentation has been improved by the development of computer based data acquisition units. Replacing traditional multichannel analyzers, these computer controlled units provide increased flexibility, improved capacity and ease of data handling. The systems designed range from a simple Apple II interface, to a high performance self contained computer controlled unit. The computerized spectrometers feature two independent channels, allowing for acquisition of the spectrum of interest and of a simultaneous calibration spectra, as well as software controlled frequency of operation. Moessbauer spectroscopy is applied to amorphous Fe based alloys to study the correlations among hyperfine interactions, and to study the crystallization behaviour of these alloys. Special attention has been payed to the quadrupole interaction in the amorphous phases. Careful data analysis, making use of the above mentioned program, is used in an attempt to determine the complex magnetic structures found in various iron phosphides. The usefulness of the Ni-61 isotope for Moessbauer spectroscopy has been investigated. (author)

  17. Moessbauer spectroscopy and transition metal chemistry. Fundamentals and applications

    International Nuclear Information System (INIS)

    Guetlich, Philipp; Trautwein, Alfred X.

    2011-01-01

    Moessbauer spectroscopy is a profound analytical method which has nevertheless continued to develop. The authors now present a state-of-the art book which consists of two parts. The first part details the fundamentals of Moessbauer spectroscopy and is based on a book published in 1978 in the Springer series 'Inorganic Chemistry Concepts' by P. Guetlich, R. Link and A.X. Trautwein. The second part covers useful practical aspects of measurements, and the application of the techniques to many problems of materials characterization. The update includes the use of synchroton radiation and many instructive and illustrative examples in fields such as solid state chemistry, biology and physics, materials and the geosciences, as well as industrial applications. Special chapters on magnetic relaxation phenomena (S. Morup) and computation of hyperfine interaction parameters (F. Neese) are also included. An attached CD-ROM with more than 400 full-color PowerPoint images provides self-explanatory examples. The book concentrates on teaching the technique using theory as much as needed and as little as possible. The reader will learn the fundamentals of the technique and how to apply it to many problems of materials characterization. Transition metal chemistry, studied on the basis of the most widely used Moessbauer isotopes, is in the foreground. (orig.)

  18. Gas flow counter conversion electron Moessbauer spectroscopy (GFC-CEMS)

    International Nuclear Information System (INIS)

    Williamson, A.; Vijay, Y.K.; Jain, I.P.

    1999-01-01

    Conversion Electron Moessbauer Spectroscopy (CEMS) is well established technique to study surface properties of materials. However non availability of commercial experimental set up and complexity of operational parameters have been restricting the working experimental groups with in the country and abroad. In this paper we have presented the development work for the design of Gas Flow Counter (GFC), e.g. convenient sample mount, grounding, steady flow rate adjustment and minimum He-losses so that the detector operation and installation becomes convenient and dependable. The basic design is modified e.g. large volume to maintain steady gas flow, sample mount close to central wire and O-ring fitted flange. The CEMS spectra are recorded using conventional Moessbauer drive and 57 Co source. The calibrated spectrum shows a detection efficiency of about 20% for natural iron and steel foil. The CEMS spectrum for FeTi bulk and transmission Moessbauer Spectroscopy (TMS) spectrum of FeTi thin film deposited by vacuum evaporation on thin glass substrate were recorded to test the performance of GFC-CEMS. (author)

  19. Structural and Electronic Properties Study of Colombian Aurifer Soils by Moessbauer Spectroscopy and X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Bustos Rodriguez, H., E-mail: hbustos@ut.edu.co; Rojas Martinez, Y.; Oyola Lozano, D. [Universidad del Tolima, Departamento de Fisica (Colombia); Perez Alcazar, G. A.; Fajardo, M. [Universidad del Valle, Departamento de Fisica (Colombia); Mojica, J. [Ingeominas Valle, Departamento de Geologia (Colombia); Molano, Y. J. C. [Universidad Nacional, Departamento de Geologia (Colombia)

    2005-02-15

    In this work a study on gold mineral samples is reported, using optical microscopy, X-ray diffraction (XRD) and Moessbauer spectroscopy (MS). The auriferous samples are from the El Diamante mine, located in Guachavez-Narino (Colombia) and were prepared by means of polished thin sections. The petrography analysis registered the presence, in different percentages that depend on the sample, of pyrite, quartz, arsenopyirite, sphalerite, chalcopyrite and galena. The XRD analysis confirmed these findings through the calculated cell parameters. One typical Rietveld analysis showed the following weight percent of phases: 85.0% quartz, 14.5% pyrite and 0.5% sphalerite. In this sample, MS demonstrated the presence of two types of pyrite whose hyperfine parameters are {delta}{sub 1} = 0.280 {+-} 0.002 mm/s and {Delta}{sub 1} = 0.642 {+-} 0.002 mm/s, {delta}{sub 2} = 0.379 {+-} 0.002 mm/s and {Delta}{sub 2} = 0.613 {+-} 0.002 mm/s.

  20. Structural and Electronic Properties Study of Colombian Aurifer Soils by Moessbauer Spectroscopy and X-ray Diffraction

    International Nuclear Information System (INIS)

    Bustos Rodriguez, H.; Rojas Martinez, Y.; Oyola Lozano, D.; Perez Alcazar, G. A.; Fajardo, M.; Mojica, J.; Molano, Y. J. C.

    2005-01-01

    In this work a study on gold mineral samples is reported, using optical microscopy, X-ray diffraction (XRD) and Moessbauer spectroscopy (MS). The auriferous samples are from the El Diamante mine, located in Guachavez-Narino (Colombia) and were prepared by means of polished thin sections. The petrography analysis registered the presence, in different percentages that depend on the sample, of pyrite, quartz, arsenopyirite, sphalerite, chalcopyrite and galena. The XRD analysis confirmed these findings through the calculated cell parameters. One typical Rietveld analysis showed the following weight percent of phases: 85.0% quartz, 14.5% pyrite and 0.5% sphalerite. In this sample, MS demonstrated the presence of two types of pyrite whose hyperfine parameters are δ 1 = 0.280 ± 0.002 mm/s and Δ 1 = 0.642 ± 0.002 mm/s, δ 2 = 0.379 ± 0.002 mm/s and Δ 2 = 0.613 ± 0.002 mm/s.

  1. Copper(II) cyanido-bridged bimetallic nitroprusside-based complexes: Syntheses, X-ray structures, magnetic properties, 57Fe Moessbauer spectroscopy and thermal studies

    International Nuclear Information System (INIS)

    Travnicek, Zdenek; Herchel, Radovan; Mikulik, Jiri; Zboril, Radek

    2010-01-01

    Three heterobimetallic cyanido-bridged copper(II) nitroprusside-based complexes of the compositions [Cu(tet)Fe(CN) 5 NO].H 2 O (1), where tet=N,N'-bis(3-aminopropyl)ethylenediamine, [Cu(hto)Fe(CN) 5 NO].2H 2 O (2), where hto=1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]octadecane and [Cu(nme) 2 Fe(CN) 5 NO].H 2 O (3), where nme=N-methylethylenediamine, were synthesized and characterized by elemental analyses, 57 Fe Moessbauer and FTIR spectroscopies, thermal analysis, magnetic measurements and single-crystal X-ray analysis. The products of thermal degradation processes of 2 and 3 were studied by XRD, 57 Fe Moessbauer spectroscopy, SEM and EDS, and they were identified as mixtures of CuFe 2 O 4 and CuO. - Three heterobimetallic cyano-bridged copper(II) nitroprusside-based complexes of the general compositions of [Cu(L)Fe(CN) 5 NO].xH 2 O, where L=N,N'-bis(3-aminopropyl)ethylenediamine (complex 1), 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]-octadecane (complex 2) and N-methylethylenediamine (complex 3), were synthesized, and fully structurally and magnetically characterized. SEM, EDS, XRD and 57 Fe Moessbauer experiments were used for characterization of thermal decomposition products of complexes 2 and 3.

  2. Moessbauer effect studies with actinides

    International Nuclear Information System (INIS)

    Stone, J.A.

    1966-01-01

    Moessbauer resonance studies in the actinide elements offer a new technique for measuring solid-state properties to a region of the periodic chart where such information is relatively sparse. It is well known that the actinides, the elements with atomic numbers from 90 to 103, form a transition series due to filling of the 5f electron shell, analogous to the rare-earth series in which the 4f shell is filled. Like the rare earths, the actinide metals and compounds are expected to exhibit a variety of interesting magnetic properties, but, unlike the rare earths, there have been few studies of the magnetic behaviour of actinides, and these properties are largely unknown. The chemical properties of the actinides have been studied somewhat more extensively, and, in contrast to the rare earths, form a multiplicity of stable valence states, especially in the lighter members of the series. It is just these properties, magnetic and chemical, for which the Moessbauer effect is a valuable probe, sensitive to the magnetic and electric environment of an atom. The rare-earth series has been a particularly fruitful region in terms of the number of elements which have been shown to exhibit the Moessbauer effect, and for this reason the exploitation of the Moessbauer effect to yield new solid-state and chemical information on the rare earths is a highly active field of research today. There is every reason to believe that the actinides can be similarly studied by the Moessbauer effect. 43 refs, 6 figs, 4 tabs

  3. Preparation of thin targets from powders for Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Jurela, Z.; Jokic, T.; Goncic, B.

    1979-01-01

    To study radiation damage in the specimen bombarded by the beams of fast particles the Moessbauer spectroscopy can be used. This is one of nondestructive methods for studying radiation damage. The use of this method of investigation and sputtering processes as well as for the study of the phenomena associated with these processes. These studies enable the complete image of the above processes. In this work we shall discuss the preparation of thin targets made from powder material. the method is based mainly on the use of various compounds of iron. Under the influence of the bombardment by fast ions the transformations of the iron compounds occur. (author)

  4. Moessbauer spectroscopy characterization of Zr-Nb-Fe phases

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C.P. [CONICET, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina)]. E-mail: ciramos@cnea.gov.ar; Granovsky, M.S. [CAC-CNEA, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina); Saragovi, C. [CAC-CNEA, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina)

    2007-02-01

    The aim of this work was the characterization of the ternary phases and of those coming from the corresponding binary systems in the Zr-Nb-Fe diagram by means of Moessbauer spectroscopy. This is part of a complete study involving a tentative isothermal section at 900 deg. C of the center of the Zr-Nb-Fe diagram which will be published elsewhere. Zr-Nb-Fe alloys with Nb contents between 5 and 50 at% and Fe contents between 10 and 60 at% were analyzed after a heat treatment at 900 deg. C for 4 month. Moessbauer characterization of the phases was complemented by optical and scanning electron microscopies, X-ray diffraction and electron microprobe analysis. From the obtained results it can be inferred that Fe in both of the Laves phases present in this system (Zr(FeNb){sub 2} and (ZrNb)Fe{sub 2}) sees different environments, producing quadrupole splitting and hyperfine field distributions, respectively. Two types of body centered cubic {beta} phases (Zr-rich and Nb-rich) were found having noticeable differences in their Moessbauer parameters. Furthermore it was shown that the ternary Fe(NbZr){sub 2} compound would show magnetic character at low temperatures. Concentration dependence of the hyperfine parameters and their relations with the lattice parameters contributed to the structural characterization of the phases.

  5. Moessbauer spectroscopy characterization of Zr-Nb-Fe phases

    International Nuclear Information System (INIS)

    Ramos, C.P.; Granovsky, M.S.; Saragovi, C.

    2007-01-01

    The aim of this work was the characterization of the ternary phases and of those coming from the corresponding binary systems in the Zr-Nb-Fe diagram by means of Moessbauer spectroscopy. This is part of a complete study involving a tentative isothermal section at 900 deg. C of the center of the Zr-Nb-Fe diagram which will be published elsewhere. Zr-Nb-Fe alloys with Nb contents between 5 and 50 at% and Fe contents between 10 and 60 at% were analyzed after a heat treatment at 900 deg. C for 4 month. Moessbauer characterization of the phases was complemented by optical and scanning electron microscopies, X-ray diffraction and electron microprobe analysis. From the obtained results it can be inferred that Fe in both of the Laves phases present in this system (Zr(FeNb) 2 and (ZrNb)Fe 2 ) sees different environments, producing quadrupole splitting and hyperfine field distributions, respectively. Two types of body centered cubic β phases (Zr-rich and Nb-rich) were found having noticeable differences in their Moessbauer parameters. Furthermore it was shown that the ternary Fe(NbZr) 2 compound would show magnetic character at low temperatures. Concentration dependence of the hyperfine parameters and their relations with the lattice parameters contributed to the structural characterization of the phases

  6. 57Fe Moessbauer spectroscopy study of phlogopite megacrysts from an evolved carbonatitic kimberlite in the northeastern Oman Mountains

    International Nuclear Information System (INIS)

    Al-Rawas, A. D.; Nasir, S.; Gismelseed, A. M.

    2008-01-01

    The Fe oxidation degree determined by 57 Fe Moessbauer spectroscopy and microprobe was used to characterize fresh and altered phlogopite megacrysts from an evolved carbonatitic kimberlite from northeastern Oman. The Quadrupole splitting (QS) varies between 2.19 and 2.48 mm/s (Fe 2+ ) in the fresh phlogopite samples and between 2.40 and 2.47 mm/s in the altered phlogopite samples. The quadrupole splitting of the Fe 3+ doublets varies between 0.66 and 0.85 mm/s in the fresh samples. The altered phlogopite samples show three Fe 3+ doublets; the first show a quadrupole splitting between 0.97 and 1.13, the second quadrupole splitting varies between 0.24 and 0.46 mm/s and the third varies between - 0.23 and - 0.35 mm/s. The phlogopite was observed to have an average Fe 3+ /Fe total of 35% to 37%, and corresponds to fresh phlogopite. The second one results from the alteration of the first type, and the Fe 3+ /Fe total ranges between 40% and 57%. Tetrahedral Fe 3+ ions were confirmed in the altered phlogopite samples. Quantitative Fe site distributions can be obtained from room-temperature Moessbauer data if the different recoilless factors for octahedral Fe 2+ and tetrahedral Fe 3+ are considered. The observed isomer shifts are consistent with Moessbauer temperatures of 330 K, reported in the literature for tetrahedral and octahedral Fe 3+ and Fe 2+ in phlogopite. The results are compared to those obtained for natural and synthetic phlogopite from worldwide.

  7. Moessbauer study of sediment alteration produced by heat treatment

    International Nuclear Information System (INIS)

    Labenski de Kanter, F.; Duhalde, S.; Saragovi, C.; March, R.J.

    1994-01-01

    Pincenvent (France) cooking-place silt-like sediments have been studied by using Moessbauer spectroscopy and characterized by using X-ray diffraction (XRD). The sediments were treated at 400, 600, 800 and 1000 C under oxidizing conditions. We discuss the results and we suggest a ''Moessbauer thermometer'' to be used to recognize the temperatures and atmosphere ancient people used in their cooking-places. (orig.)

  8. A versatile gas-flow proportional counter for Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bibicu, I., E-mail: bibicu@infim.ro [National Institute for Materials Physics (Romania); Nicolescu, G. [IFIN-HH, National Institute of Physics and Nuclear Engineering (Romania); Cretu, C. [Transylvania University, Physics Department (Romania)

    2009-07-15

    This article presents a versatile gas-flow proportional counter for surface and transmission Moessbauer spectroscopy, suitable for studies with {sup 57}Fe, {sup 119}Sn and {sup 151}Eu isotopes. The main advantages obtained by new design are: (1) the height of the detection volume can be changed in large limits from 0 to 38 mm, (2) the detection volume can be choose symmetrical or not in respect with anode plan, (3) the anode replacement is easily (4) and different anode configuration can be used. The characteristics of the detector, operating at room temperature, are reported.

  9. Moessbauer study of El-Bahrain meteorite

    International Nuclear Information System (INIS)

    Bahgat, A.A.; Ahmed, M.A.; Ramadan, T.M.

    2000-01-01

    A stone of brick-like shape, measuring roughly 25 x 12.5 x 10.5 cm 3 and weighing 14 kg was found in 1983, in the western desert of Egypt. The meteorite was named El-Bahrain meteorite and classified as L-chondrite. Principal constituents of El-Bahrain meteorite have been studied by means of Moessbauer spectroscopy. The chemical composition as obtained by the conventional wet analyses of L-chondritic meteorites showed that the meteorite contains 23,38% Fe and 1.23% Ni. While the analysis of the atomic absorption showed the presence of 27.03% as a total iron. The Moessbauer analysis of El-Bahrain meteorite showed that the iron constituent minerals were determined to be olivine, metallic iron-nickel alloys (kamacite, taenite and tetrataenite), ferrous sulfide (troilite) and weathering products such as maghemite and nanocrystalline hematite. The structure of meteoritic iron obtained by the Moessbauer analysis has been discussed on the basis of these constituents. (author)

  10. Study Moessbauer of chromites of South Africa

    International Nuclear Information System (INIS)

    Lopez, Ada; Velazquez, R.

    1997-01-01

    Coming natural chromites from South Africa they were studied by spectroscopy Moessbauer and X-rays diffraction. The ionic distribution of the ions of iron is reported in the area tetrahedral and octahedral in the structure showing that the pattern an orderly distribution, the chromites nearby to an inverse spinel. The microanalysis shows a certain variability in the composition in the coming specimen of the same area and could be the cause the apparent evolution of the chromite in the laterization process. We try to compare these results with a similar study coming f rom basaltic rocks of the Nemby Hill in oriental region of Paraguay [es

  11. Moessbauer study of Slovak meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Lipka, J.; Sitek, J.; Dekan, J., E-mail: julius.dekan@stuba.sk; Degmova, J. [Slovak University of Technology, Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology (Slovakia); Porubcan, V. [Comenius University, Faculty of Mathematics and Physics (Slovakia)

    2013-04-15

    {sup 57}Fe Moessbauer spectroscopy was used as an analytical tool in the investigation of iron containing compounds of two meteorites (Rumanova and Kosice) out of total of six which had fallen on Slovak territory. In the magnetic fraction of the iron bearing compounds in the Rumanova meteorite, maghemite, troilite and Fe-Ni alloy were identified. In the non-magnetic fraction silicate phases were found, such as olivine and pyroxene. The paramagnetic component containing Fe{sup 3 + } ions corresponds probably to small superparamagnetic particles. The Kosice meteorite was found near the town of Kosice in February 2010. Its magnetic fraction consists of a Fe-Ni alloy with the Moessbauer parameters of the magnetic field corresponding to kamacite {alpha}-Fe(Ni, Co) and troilite. The non-magnetic part consists of Fe{sup 2 + } phases such as olivine and pyroxene and traces of a Fe{sup 3 + } phase. The main difference between these meteorites is their iron oxide content. These kinds of analyses can bring important knowledge about phases and compounds formed in extraterrestrial conditions, which have other features than their terrestrial analogues.

  12. Influence of Heat Treatment on Ordering Process in Fe72Al28 Alloy Studied by Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Kansy, J.; Hanc, A.; Giebel, D.

    2011-01-01

    The paper discusses a theoretical model that associates the shape of Moessbauer spectrum with the configuration of atoms in local surroundings of the Moessbauer nuclide. The model has been implemented to a computer program which was used to analyse the Moessbauer spectra of Fe 72 Al 28 alloys after various heat treatments. Basing on the determined configuration of atoms, the long range ordering parameter was estimated. (authors)

  13. High pressure Moessbauer spectroscopy of perovskite iron oxide

    CERN Document Server

    Nasu, S; Morimoto, S; Kawakami, T; Kuzushita, K; Takano, M

    2003-01-01

    High-pressure sup 5 sup 7 Fe Moessbauer spectroscopy using a diamond anvil cell has been performed for perovskite iron oxides SrFeO sub 3 , CaFeO sub 3 and La sub 1 sub / sub 3 Sr sub 2 sub / sub 3 O sub 3. The charge states and the magnetic dependency to pressure were determined. Pressure magnetic phase diagrams of these perovskite iron oxides are determined up to about 70 GPa. To be clear the magnetic ordered state, they are measured up to 7.8 T external magnetic fields at 4.5K. The phase transition of these perovskite oxides to ferromagnetisms with high magnetic ordered temperature is observed. In higher pressure, high spin-low spin transition of oxides besides CaFeO sub 3 is generated. The feature of Moessbauer spectroscopy, perovskite iron oxide and Moessbauer spectroscopy under high pressure are explained. (S.Y.)

  14. High pressure Moessbauer spectroscopy of perovskite iron oxide

    International Nuclear Information System (INIS)

    Nasu, Saburo; Suenaga, Tomoya; Morimoto, Shotaro; Kawakami, Takateru; Kuzushita, Kaori; Takano, Mikio

    2003-01-01

    High-pressure 57 Fe Moessbauer spectroscopy using a diamond anvil cell has been performed for perovskite iron oxides SrFeO 3 , CaFeO 3 and La 1/3 Sr 2/3 O 3 . The charge states and the magnetic dependency to pressure were determined. Pressure magnetic phase diagrams of these perovskite iron oxides are determined up to about 70 GPa. To be clear the magnetic ordered state, they are measured up to 7.8 T external magnetic fields at 4.5K. The phase transition of these perovskite oxides to ferromagnetisms with high magnetic ordered temperature is observed. In higher pressure, high spin-low spin transition of oxides besides CaFeO 3 is generated. The feature of Moessbauer spectroscopy, perovskite iron oxide and Moessbauer spectroscopy under high pressure are explained. (S.Y.)

  15. Use of Moessbauer spectroscopy to determine the effect of salinity on the speciation of triorganotins in Anacostia River sediments

    Energy Technology Data Exchange (ETDEWEB)

    Eng, George; Song Xueqing [University of the District of Columbia, Department of Chemistry and Physics and Agricultural Experimental Station (United States); May, Leopold, E-mail: may@cua.edu [Catholic University of America, Department of Chemistry (United States)

    2006-06-15

    The speciation of several tributyltin and triphenyltin compounds under varying salinity conditions (0, 20, 40 and 60%) was studied by Moessbauer spectroscopy in both anaerobic and aerobic Anacostia River sediments. The Moessbauer spectral parameters of the spiked sediments indicated that changes in the salinity did not affect the speciation of the tin compounds in either aerobic or anaerobic sediments.

  16. Corrosion of steam generator pipelines analysed using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Slugen, V.; Lipka, J.; Toth, I.; Hascik, J.; Hinca, R.; Lehota, M.

    2003-01-01

    The variability of the properties and the composition of the corrosion products of the stainless CrNi and mild steels in dependence on the conditions (temperature, acidity, etc.) is of such range that, in practice, it is impossible to determine the properties of the corrosion products for an actual case from the theoretical data only. Since the decontamination processes for the materials of the water-cooled reactor (VVER-440) secondary circuits are in the progress of development, it is necessary to draw the needed information by the measurement and analysis of the real specimens. The corrosion layers was separated by scraping the rust off the surface and the powder samples were studied by transmission Moessbauer spectroscopy. It should be noted that the gamma spectroscopic measurements give no evidence of the presence of low-energy gamma radiation emitted from the samples. The scraped specimen powder was homogenised (using a 50 μm sieve) and fixed into a special holder. The 57 Co in Rh matrix was used as the radioactive Moessbauer source. Measured spectra were fitted using program NORMOS SITE. According to the results obtained from Moessbauer spectra, it is possible to establish that the main component of secondary circuit's corrosion products is magnetite Fe 3 O 4 . Next components are hematite α-Fe 2 O 3 and hydroxide akagenite β-FeOOH, which is characterised by significant paramagnetic doublet in the middle of spectra. The sextets corresponding to base materials (martensite and austenite steels) were identified in all measured spectra. (author)

  17. Molecular Sensors for Moisture Detection by Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Renz, F.; Souza, P. A. de; Klingelhoefer, G.; Goodwin, H. A.

    2002-01-01

    A parameter of importance in various industrial and commercial applications is sensitivity to moisture. A new class of molecular sensors which enable the qualitative and quantitative determination of air moisture (high selectivity and sensitivity) by application of Moessbauer spectroscopy as the probe technique has been investigated. The electronic properties of the iron-containing sensor depend upon the presence of moisture which is taken up by it and this process is accompanied by a change in electronic spin ground state which can be detected by Moessbauer spectroscopy. The sensor is suitable for in-field and industrial application using the recently developed Moessbauer spectrometer MIMOS II. Possible suitability for the detection of moisture in extraterrestrial environments is considered.

  18. Absorber transmissivities in 57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ballet, O.

    1985-01-01

    Some useful relations are derived for the polarization dependent optical index of 57 Fe Moessbauer absorbers. Real rotation matrices are extensively used and, besides wave-direction dependence, their properties simplify also the treatment of texture and f-anisotropy. The derivation of absorber transmissivities from the optical index is discussed with a special emphasis on line overlapping. (Auth.)

  19. In-situ Moessbauer spectroscopy with MIMOS II

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, Iris, E-mail: fleischi@uni-mainz.de; Klingelhoefer, Goestar [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University of Mainz (Germany); Morris, Richard V. [NASA Johnson Space Center (United States); Schroeder, Christian [University of Bayreuth and University of Tuebingen (Germany); Rodionov, Daniel [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University of Mainz (Germany); Souza, Paulo A. de [Tasmanian ICT Centre (Australia); Collaboration: MIMOS II Team

    2012-03-15

    The miniaturized Moessbauer spectrometer MIMOS II was developed for the exploration of planetary surfaces. Two MIMOS II instruments were successfully deployed on the martian surface as payload elements of the NASA Mars Exploration Rover (MER) mission and have returned data since landing in January 2004. Moessbauer spectroscopy has made significant contributions to the success of the MER mission, in particular identification of iron-bearing minerals formed through aqueous weathering processes. As a field-portable instrument and with backscattering geometry, MIMOS II provides an opportunity for non-destructive in-situ investigations for a range of applications. For example, the instrument has been used for analyses of archaeological artifacts, for air pollution studies and for in-field monitoring of green rust formation. A MER-type MIMOS II instrument is part of the payload of the Russian Phobos-Grunt mission, scheduled for launch in November 2011, with the aim of exploring the composition of the martian moon Phobos. An advanced version of the instrument, MIMOS IIA, that incorporates capability for elemental analyses, is currently under development.

  20. Electronic phase diagrams and competing ground states of complex iron pnictides and chalcogenides. A Moessbauer spectroscopy and muon spin rotation/relaxation study

    Energy Technology Data Exchange (ETDEWEB)

    Kamusella, Sirko

    2017-03-01

    In this thesis the superconducting and magnetic phases of LiOH(Fe,Co)(Se,S), CuFeAs/CuFeSb, and LaFeP{sub 1-x}As{sub x}O - belonging to the 11, 111 and 1111 structural classes of iron-based arsenides and chalcogenides - are investigated by means of {sup 57}Fe Moessbauer spectroscopy and muon spin rotation/relaxation (μSR). Of major importance in this study is the application of high magnetic fields in Moessbauer spectroscopy to distinguish and characterize ferro- (FM) and antiferromagnetic (AFM) order. A user-friendly Moessbauer data analysis program was developed to provide suitable model functions not only for high field spectra, but relaxation spectra or parameter distributions in general. In LaFeP{sub 1-x}As{sub x}O the reconstruction of the Fermi surface is described by the vanishing of the Γ hole pocket with decreasing x. The continuous change of the orbital character and the covalency of the d-electrons is shown by Moessbauer spectroscopy. A novel antiferromagnetic phase with small magnetic moments of ∼ 0.1 μ{sub B} state is characterized. The superconducting order parameter is proven to continuously change from a nodal to a fully gapped s-wave like Fermi surface in the superconducting regime as a function of x, partially investigated on (O,F) substituted samples. LiOHFeSe is one of the novel intercalated FeSe compounds, showing strongly increased T{sub C} = 43 K mainly due to increased interlayer spacing and resulting two-dimensionality of the Fermi surface. The primary interest of the samples of this thesis is the simultaneously observed ferromagnetism and superconductivity. The local probe techniques prove that superconducting sample volume gets replaced by ferromagnetic volume. Ferromagnetism arises from magnetic order with T{sub C} = 10 K of secondary iron in the interlayer. The tendency of this system to show (Li,Fe) disorder is preserved upon (Se,S) substitution. However, superconductivity gets suppressed. The results of Moessbauer spectroscopy

  1. Current opinion about maximum entropy methods in Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Szymanski, K

    2009-01-01

    Current opinion about Maximum Entropy Methods in Moessbauer Spectroscopy is presented. The most important advantage offered by the method is the correct data processing under circumstances of incomplete information. Disadvantage is the sophisticated algorithm and its application to the specific problems.

  2. Italian money tested for forgery by moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ortalli, I.; Pedrazzi, G.; Jiang Keyu; Zhang Xiufang

    1993-01-01

    Italian money has been investigated by Moessbauer spectroscopy. The results indicated that the spectrum of a 10000 lire bank-note consisted of three magnetic sextets and two quadrupole doublets, the spectrum of a 5000 lire note consisted of two Zeeman sextets, but in the 'false' money there are two quadrupole doublets only

  3. A microprocessor based multiscaling data acquisition system for moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bohm, C.; Ekdahl, T.

    1985-01-01

    A microprocessor based data acquisition system is described, which was developed for use in Moessbauer spectroscopy. It is designed to record two spectra simultaneously, one of which could be a calibration spectrum. It is autonomous, but uses a host computer for initialization and permanent storage of data. The host communication software is also described. (Author)

  4. A proportional counter for efficient backscatter Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Cudny, W.; Holnicka, J.; Walentek, J.

    1979-01-01

    The authors present a novel gas-tight proportional counter with flat beryllium windows for backscatter Moessbauer spectroscopy. The krypton-filled counter has a geometry that approaches 2π and a resolution of 12% fwhm for the 14.4 keV line of 57 Fe, and is easy to manufacture. (Auth.)

  5. Surface analysis in steel nitrides by using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Figueiredo, R.S. de.

    1991-07-01

    The formation of iron nitride layer at low temperatures, 600-700 K, by Moessbauer spectroscopy is studied. These layers were obtained basically through two different processes: ion nitriding and ammonia gas nitriding. A preliminary study about post-discharge nitriding was made using discharge in hollow cathode as well as microwave excitation. The assembly of these chambers is also described. The analysis of the nitrided samples was done by CEMS and CXMS, aided by optical microscopy, and the CEMS and CXMS detectors were constructed by ourselves. We also made a brief study about these detectors, testing as acetone as the mixture 80% He+10% C H 4 as detection gases for the use of CEMS. The surface analysis of the samples showed that in the ammonia gas process nitriding the nitrided layer starts by the superficial formation of an iron nitride rich nitrogen. By thermal evolution this nitride promotes the diffusion of nitrogen and the formation of other more stable nitrides. (author)

  6. Detectability in a derivative Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Yoshimura, Takeaki; Miyamoto, Masashi; Wakabayashi, Nobuo

    1978-01-01

    In Moessbauer spectrometry, a criterion for detecting a faint peak under the condition that the peak is superimposed onto a tail of a large and broad peak is discussed. By adopting a derivative method, it is found that the criterion is improved in comparison with a usual method, and that the condition for determining the modulation amplitude W/2 is 1.5 GAMMA 1 1 where GAMMA 1 is the spectral linewidth of the faint peak. (auth.)

  7. Moessbauer spectroscopy of Fe-Mn-Cu alloys

    International Nuclear Information System (INIS)

    Paduani, Clederson; Krause, Joao Carlos; Yoschida, M.I. Soares

    2004-01-01

    Full text: Although a continuous series of solid solutions exists between Cu and Mn, Fe and Cu are miscible only a few percent at higher temperatures. In moderately concentrated Cu-Mn alloys the Mn moments are bound to the long ranged antiferromagnetic order and the perpendicular components form an X-Y spin glass. Copper alloys are largely employed in various industrial applications. In this work we study the magnetic properties of iron-rich disordered Fe-Mn-Cu alloys with the bcc structure with the experimental techniques of X-ray diffraction (XRD), Moessbauer spectroscopy (MS) and thermogravimetry (TGA). We investigate the formation of a solid solution with the bcc structure as well as the effect of the composition on the structural and magnetic properties of these alloys. A Rietveld analysis of the XRD diffractograms indicate that all prepared samples are single phase and are well crystallized with a bcc structure. (author)

  8. The Moessbauer spectroscopy in the characterization of atmospheric corrosion products

    International Nuclear Information System (INIS)

    Hernandez Torres, D.; Leiva Ronda, P.; Gomez, J.; Ronda, M.

    1996-01-01

    A study of corrosion products on mild steel formed after 1 and 5 years exposure in two industrial coastal weathering stations in the Bay from Matanzas City, Cuba, has been carried out. Structural analysis was conducted using mainly transmission Moessbauer Spectroscopy and the X-ray diffraction as complementary technique. The main phases found in the specimen exposed to high chloride containing environment were: lepidocrocite (γ- FeOOH), goethite (α- FeOOH) and magnetite concentration was the lowest, the phases found were γ- FeOOH and α- FeOOH, and the phase transformation proposed was γ- FeOOh -> α- Fe-OOH. In this station were found also amorphous corrosion products. There amorphous phases could be responsible for the lowest levels of corrosion on steel in this station

  9. Application of Moessbauer spectroscopy on corrosion products of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Dekan, J., E-mail: julius.dekan@stuba.sk; Lipka, J.; Slugen, V. [Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, SUT (Slovakia)

    2013-04-15

    Steam generator (SG) is generally one of the most important components at all nuclear power plants (NPP) with close impact to safe and long-term operation. Material degradation and corrosion/erosion processes are serious risks for long-term reliable operation. Steam generators of four VVER-440 units at nuclear power plants V-1 and V-2 in Jaslovske Bohunice (Slovakia) were gradually changed by new original 'Bohunice' design in period 1994-1998, in order to improve corrosion resistance of SGs. Corrosion processes before and after these design and material changes in Bohunice secondary circuit were studied using Moessbauer spectroscopy during last 25 years. Innovations in the feed water pipeline design as well as material composition improvements were evaluated positively. Moessbauer spectroscopy studies of phase composition of corrosion products were performed on real specimens scrapped from water pipelines or in form of filters deposits. Newest results in our long-term corrosion study confirm good operational experiences and suitable chemical regimes (reduction environment) which results mostly in creation of magnetite (on the level 70 % or higher) and small portions of hematite, goethite or hydrooxides. Regular observation of corrosion/erosion processes is essential for keeping NPP operation on high safety level. The output from performed material analyses influences the optimisation of operating chemical regimes and it can be used in optimisation of regimes at decontamination and passivation of pipelines or secondary circuit components. It can be concluded that a longer passivation time leads more to magnetite fraction in the corrosion products composition.

  10. Moessbauer spectroscopic studies of magnetically ordered biological materials

    International Nuclear Information System (INIS)

    Dickson, D.P.E.

    1987-01-01

    This paper discusses recent work showing the application of Moessbauer spectroscopy to the study of the properties of the magnetically ordered materials which occur in a variety of biological systems. These materials display a diversity of behaviour which provides good examples of the various possibilities which can arise with iron-containing particles of different compositions and sizes. (orig.)

  11. Moessbauer study of rock paintings from Minas Gerais (Brazil)

    International Nuclear Information System (INIS)

    Costa, G.M. da; Jesus Filho, M.F. de; Cruz Souza, L.A.

    1991-01-01

    Four samples of a wall containing rock paintings have been studied by Moessbauer spectroscopy in combination with optical microscopy analysis and X-ray diffraction. Hematite and goethite were identified as the pigments responsible for the colors and the mineral tinsleyite, as the principal component of a light pink layer that is present in some parts of the wall. (orig.)

  12. Moessbauer study of amorphous alloys irradiated with energetic heavy ions

    International Nuclear Information System (INIS)

    Kuzmann, E.; Spirov, I.N.

    1984-01-01

    The Moessbauer spectroscopy was applied to study radiation damages in amorphous alloys irradiated with 40 Ar (E=225 MeV) or 132 Xe (E=120 MeV) ions at room temperature. In the magnetically splitted Moessbauer spectra the dose-dependent decreases of the intensity of the 2nd and 5th lines as well as of the average hyperfine magnetic field were observed. The changes weAe also analysed using the hyperfine field distribution obtained from the spectra. The results are interpreted in terms of defect creation and structural changes of shortrange order of irradiated amorphoys alloys

  13. Moessbauer spectroscopy of 57Fe and the evolution of the solar system

    International Nuclear Information System (INIS)

    Knudsen, J.M.

    1990-01-01

    The article starts with a brief review of ideas on the origin of the solar system, with emphasis on the cosmic history of the element iron. Some examples of the application of Moessbauer spectroscopy to the study of iron compounds from various types of meteorites, which represent different stages of the evolution of the planetary system, then follow. (orig.)

  14. Fe-57 Moessbauer effect studies of some ancient Chinese pottery from Xudun

    Energy Technology Data Exchange (ETDEWEB)

    Yuanfu, Hsia; Zheng, Hu; Rongchuan, Liu; Qi, Zeng; Zhengfang, Yu; Yufang, Zheng

    1988-02-01

    18 Sherds (4500 B.C.-4000 B.C.) unearthed from different archaeological layers at the same place were studied by Moessbauer spectroscopy. The original firing atmosphere can be deduced from the ratio of the Fe/sup 2+/ to Fe/sup 3+/. By comparing the Moessbauer parameters of the original and the refired sherds, we can assess the original firing temperatures.

  15. A methodological proposal for ancient kiln simulation analyzed by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Flores, E.; Fernandes, B.; Flores, E.; Fernandez, B.

    1988-01-01

    In previous papers scientistis from different countries have reported simulating incomplete methodologies for ancient kiln firing conditions. Results from clays fired in a first working hypothesis are presented to end as a methodological proposal for simulation. This study was done through Moessbauer spectroscopy. The fired clay used presented a Fe 2+ and Fe 3+ spectrum in octahedric sites. Moessbauer parameters complemented by other studies indicate illite is the predominant clay mineral. A trait of the parameters behaviour in presence of temperature is reported. (author)

  16. Low temperature {sup 57}Fe Moessbauer study of cucumber root

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, K; Kuzmann, E; Homonnay, Z; Vertes, A [Institute of Chemistry, Eoetvoes Lorand University, PO Box 32, 1512 Budapest (Hungary); Fodor, F [Department of Plant Physiology and Molecular Plant Biology, Eoetvoes Lorand University, PO Box 32, 1512 Budapest (Hungary); Machala, L, E-mail: kkriszti@chem.elte.h [Centre for Nanomaterial Research, Palacky University, Svobody 26, Olomouc 771 46 (Czech Republic)

    2010-03-01

    Iron uptake and distribution in cucumber root were studied with the help of {sup 57}Fe Moessbauer spectroscopy at low temperature applying external magnetic field. Cucumber was grown in iron sufficient modified Hoagland nutrient solution. Moessbauer spectra of the frozen roots taken at 4.2 and 1.5 K, at 5 T external magnetic field support the identification of the main iron species (Fe{sup III}-carboxylates, hydrous ferric oxides, Fe{sup III}-sulfate-hydroxide) suggested according to its Moessbauer spectra taken between 35-200 K [1]. The magnetic ordering temperature of the hydrous ferric oxide and Fe{sup III}-sulfate-hydroxide was found to be in the range of 4.2-1.5 K, which suggests the incorporation of H{sub 3}O{sup +}, PO{sub 4}{sup 3-} and citrate into these minerals.

  17. Moessbauer spectroscopy on the reaction center of Rhodopseudomonas viridis

    International Nuclear Information System (INIS)

    Frolov, E.; Goldanskii, V.I.; Birk, A.; Parak, F.; Fritzsch, G.; Sinning, I.; Michel, H.

    1992-01-01

    Proteins called 'reaction centers' (RC) can be isolated from many photosynthetic bacteria. They have one non-heme iron in a quinone acceptor region. The RC of Rhodopseudomonas viridis contains an additional tightly bound tetra-heme cytochrome c subunit. The electronic configuration of both cytochrome and the non-heme iron has been studied in the crystallized protein by Moessbauer spectroscopy at different redox potentials, pH-values, and with an addition of o-phenanthroline. At high potentials (E h =+500 mV) all heme irons are in the low spin Fe 3+ -state, and at low potential (E h = 1 50 mV) they are low spin Fe 2+ with the same Moessbauer parameters for all hemes independent of pH. Redox titrations change the relative area of the reduced and oxidized states in agreement with other methods. The non-heme iron shows a high spin Fe 2+ configuration independent of E h and pH with parameters comparable to those of Rhodopseudomonas sphaeroides. Surprisingly, there is strong evidence for another non-heme iron species in part of the molecules with a Fe 2+ low spin configuration. Incubation with o-phenanthroline decreases the relative Fe 2+ hs-area and increases the contribution of Fe 2+ ls-area. Above 210 K the mean square displacement, 2 >, of the RC-crystals increases more than linearly with temperature. This may be correlated with the increase of the electron transfer rate and indicates that intramolecular mobility influences the functional activity of a protein. (orig.)

  18. The magnetic moment of NiO nanoparticles determined by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bahl, C R H; Hansen, M F; Pedersen, T; Saadi, S; Nielsen, K H; Lebech, B; Moerup, S

    2006-01-01

    We have studied the magnetic properties of 57 Fe-doped NiO nanoparticles using Moessbauer spectroscopy and magnetization measurements. Two samples with different degrees of interparticle interaction were studied. In both samples the particles were characterized by high-resolution transmission electron microscopy and x-ray diffraction and found to be plate-shaped. Computer simulations showed that high-field Moessbauer data are very sensitive to the size of the uncompensated magnetic moment. From analyses of the Moessbauer spectra we have estimated that the size of the uncompensated magnetic moment is in accordance with a model based on random occupation of surface sites. The analyses of the magnetization data gave larger magnetic moments, but the difference can be explained by the different sensitivity of the two methods to a particle size distribution and by interactions between the particles, which may have a strong influence on the moments estimated from magnetization data

  19. Application of Moessbauer spectroscopy in investigating Egyptian archaeology

    International Nuclear Information System (INIS)

    Eissa, N.A.; Sallam, H.A.

    1988-01-01

    This article summarizes the results of applications of the Moessbauer spectroscopy to investigate Ancient Egyptian pottery from the periods: Ancient Egyptian (3200-525 B.C.), Greek-Roman (320 B.C.-640 A.C.) and Early Islamic (800-1000 A.C.). Many objective informations deduced about: provinance, manufacturing techniques for different domestic purposes, civilization transfer between the Arab countries, methods of colouration and applying decorating glazes, and finally dating of ancient pottery. (orig.)

  20. Characterization of Egyptian coal from Sinai using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Eissa, N.A.; Abdel Meguid, M.M.; Deriu, A.; Albanese, G.

    1983-08-01

    The presence of iron bearing minerals in coal makes the Moessbauer Spectroscopy (MS) extremely useful for characterization of coals from different localities. In this paper the MS has been applied to characterize Egyptian coal from Sinai (Maghara). The chemical analysis of this coal is given. The MS results showed that pyritic sulphur (pyrite and marcasite) is the only bearing mineral in Egyptian coal. A review is given for the iron bearing minerals in coals from different countries measured by MS. (author)

  1. Moessbauer spectroscopy of the cephalin+SnCl4 system

    International Nuclear Information System (INIS)

    Rochev, Ya.V.; Kevdin, O.P.; Kivrina, N.K.; Gilbukh, E.A.; May, L.

    1981-01-01

    A technique is developed for introducing Moessbauer labels into lipid systems. With the use of stannic chloride as a label the temperature dependences are studied for parameters of Moessbauer spectra of the cephalin+stannic chloride lipid system and of the corresponding model lipid-free system. Conclusions are made on the structure of tin complexes in the systems under study; for lipid system a line broadening is observed at temperatures above -64 deg C, that is probably due to conformational change in the lipid matrix. On the assumption of different diffusion models, the diffusion characteristics of the system studied are estimated at various temperatures. (author)

  2. Magnetic properties of the ternary carbide DyCoC2 studied by magnetization measurements, neutron diffraction and 161Dy Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Amanai, H.; Onodera, H.; Ohashi, M.; Matsuo, S.; Yamauchi, H.

    1995-01-01

    The magnetic properties of DyCoC 2 have been investigated by means of magnetization measurements, powder neutron diffraction and 161 Dy Moessbauer spectroscopy. The magnetization versus temperature curves of a single-crystalline sample reveal that the magnetic structure of DyCoC 2 is a simple collinear ferromagnetic one below T C =10.0 K. At 4.2 K, the magnitude of the Dy moment is 8.7(1)μ B , whose direction is defined by an angle of 38.0(5) from the a-axis toward the c-axis. The magnetic structure and the magnitude of the moment are also confirmed by the results of powder neutron diffraction experiments and 161 Dy Moessbauer spectroscopy, respectively. ((orig.))

  3. Moessbauer spectroscopy with a high velocity resolution: advances in biomedical, pharmaceutical, cosmochemical and nano technological research

    International Nuclear Information System (INIS)

    Oshtrakha, M.I.; Semionkina, V.A.

    2011-01-01

    . Characteristics of this system demonstrated a high stability, precision and accuracy in the measurement of Moessbauer spectra in 4096 channels. In spite of substantial increase in the measurement time, spectra measured with a high velocity resolution permitted to obtain Moessbauer hyperfine parameters with systematic errors at least 8 times less than in the case of spectra measurement in 512 channels as well as to fit complicated Moessbauer spectra with better quality. Various applications of Moessbauer spectroscopy with a high velocity resolution demonstrated new possibilities of technique. Biomedical applications. New results were obtained in the study of human liver ferritin, its pharmaceutically important models as well as liver and spleen tissues from normal and leukemia chicken; in comparative study of various human and animals' normal oxyhemoglobins and oxyhemoglobins from patients; in the study of iron containing pharmaceutical products. Cosmochemical applications. In the study of various meteorites new results were obtained in analysis of Fe-Ni alloys with variations in Ni concentration, in the study of silicate phases and Fe-Ni phosphides with crystallographically non-equivalent sites for Fe. Nanotechnological applications. New results were obtained in the study of cupric ferrite nanoparticles with tin oxide adding as well as in the study of ferric oxide nanoparticles developed for magnetic fluids for biomedical purposes. (author)

  4. Moessbauer Studies of Volhynian Basalts

    International Nuclear Information System (INIS)

    Bakun-Czubarow, N.; Milczarski, J.; Galazka-Friedman, J.; Szlachta, K.; Forder, S.

    2011-01-01

    The Volhynian basalts studied belong to the effusive-tuffogenic Volhynian Series (Slawatycze Series in Poland), being the large Ediacaran continental igneous province, that covers an area of 200 000 km 2 in the western margin of East European Craton. The series is underlain by the Cryogenian terrigenous Polesie Series with doleritic sills and dikes. The Volhynian Series consists of the rock beds belonging to the three volcanic cycles with different ratios of flood basalts to pyroclastics. The aim of the study was recognition of primary and secondary Fe-bearing minerals, particularly Fe- and Fe-Ti oxides as well as determination of iron oxidation state, that is an important tool in the search for native copper deposits in these rocks. For Moessbauer studies the following rock samples were chosen: the Polesie Series dolerites, the Volhynian Series basalts from the Ukrainian quarries and drill-holes, e.g. from the Volodymir Volhynskaya drilling hole; the Slawatycze Series basalts from Kaplonosy drill-hole in Poland. In the Kaplonosy basalts the content of magnetite decreases with depth, which may be caused by magma differentiation due to fractional crystallization, when Mg content decreases as Ti and Fe - increases in basic magma. In the Kaplonosy basalts the Fe 2+ /Fe 3+ ratio increases with depth, which points to the increase of iron oxidation with the progress of basaltic magma differentiation. (authors)

  5. Moessbauer spectroscopy characterization and electrochemical study of the kinetics of oxidation of iron in chlorinated aqueous media: structure and equilibrium diagram of green rust one

    International Nuclear Information System (INIS)

    Genin, J.M.R.; Rezel, D.; Bauer, Ph.; Olowe, A.; Beral, A.

    1986-01-01

    Moessbauer spectroscopy allows to precise the structure of akaganeite, lepidocrocite, green rust I and initial hydroxide of a simulated corrosion process of iron in chlorinated aqueous media. The characterization of the compounds during the process is coupled with E - pH recordings, yielding the kinetics of the various reactions (order and activation energy) as well as the Pourbaix diagram of Green Rust I by scanning the [Cl - ]/[OH - ] ratio. (author) 16 refs., 15 figs

  6. Moessbauer spectroscopy in Egyptian and Qatari steel industry

    International Nuclear Information System (INIS)

    Eissa, N.A.

    1984-07-01

    This paper gives an example of applying the Moessbauer Spectroscopy (MS) in steel industry in both Egypt and Qatar. The author carried out the measurements at the Moessbauer laboratories in Al-Azhar University and in Qatar University. Measurements were carried out on the raw materials and the products. It was possible to check the characteristics of the products at each stage and also the efficiency of its production. The mechanism of formation could be followed. The analysis of M spectra of plain carbon steel provides information on the different phases, reveals the effect of quenching, shows the effect of the interstitial carbon atoms and their movement during tempering. Order disorder transformation, solid solubility limits and texture of materials are mentioned. (author)

  7. Sorption-induced reversible oxidation of Fe(2) at the smectite/water interface under strictly anoxic conditions. A Moessbauer spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Gehin, A.; Charlet, L. [Laboratoire de Geophysique Interne et Tectonophysique (LGIT), Universite de Grenoble, 38 - Grenoble (France); Gehin, A. [Agence Nationale pour la Gestion des Dechets Radioactifs, ANDRA, 92 - Chatenay Malabry (France); Greneche, J.M. [Laboratoire de Physique de l' Etat Condense, UMR-CNRS 6087, 72 - Le Mans (France); Brendle, J. [Universite de Haute Alsace, Lab. des Materiaux Mineraux (LMM), 68 - Mulhouse (France); Rancourt, D.G. [Ottawa Univ., Dept. of Physics, Ontario (Canada)

    2005-07-01

    Previous studies of Fe(II) sorption onto montmorillonite have been performed with the mineral extracted from the MX80 bentonite. These studies have shown that Fe(II) can be sorbed onto clay minerals in cation exchange position. The affinity of montmorillonite for Fe(II) and Ca(II) is identical. Fe(II) may also be specifically adsorbed onto montmorillonite clay edges. Moessbauer spectroscopy confirmed the high affinity of clay surfaces for Fe(II) sorption and showed that this sorption is mainly due to a two step mechanism: Fe(II) specific adsorption, followed by oxidation of the Fe(II) sorbed. The identification of the oxidizing agent was prohibited due to the complex chemistry of the natural MX80 montmorillonite. Thus, synthetic iron-free montmorillonite was used (chemical formula: Ca{sub 0.3} (A{sub 1.4}Mg{sub 0.6}) (Si{sub 4}) O{sub 10}(OH){sub 2} ). {sup 57}Fe(II) sorption experiments were conducted in a N{sub 2} atmosphere gloves-box, in strictly anoxic conditions. Solid samples were synthesized in order to confirm the clay high affinity for Fe(II), in absence of structural oxidant, and to have a better comprehension of the sorption mechanism. Moessbauer spectra were recorded for each sample. Whereas no Fe(III) is detected in solution as pH was increased and then, a significant amount of surface sorbed Fe(III) was found to be reversibly produced, which amounts for 0-3% of total Fe in the pre-sorption edge acid region, up to 7% of total Fe when all Fe is sorbed in the neutral to alkaline pH range. From pH {approx_equal} 2 to pH {approx_equal} 7, a sorption edge plateau is observed. In this plateau, the sorbed-Fe(III)/sorbed-Fe ratio increases with pH, up to 45% at pH 7. Moessbauer spectra comparison with ferrous hydroxide, synthesized in the same redox conditions at higher pH, show that this oxidation can not be due to the trace amounts Oz in the suspension. The Moessbauer spectra components of both Fe(II) and Fe(III) appears as paramagnetic doublets: iron has

  8. Comparative study of the iron cores in human liver ferritin, its pharmaceutical models and ferritin in chicken liver and spleen tissues using Moessbauer spectroscopy with a high velocity resolution

    Energy Technology Data Exchange (ETDEWEB)

    Alenkina, I.V.; Semionkin, V.A. [Faculty of Physical Techniques and Devices for Quality Control, Ural Federal University, Ekaterinburg (Russian Federation); Faculty of Experimental Physics, Ural Federal University, Ekaterinburg (Russian Federation); Oshtrakh, M.I. [Faculty of Physical Techniques and Devices for Quality Control, Ural Federal University, Ekaterinburg (Russian Federation); Klepova, Yu.V.; Sadovnikov, N.V. [Faculty of Physiology and Biotechnology, Ural State Agricultural Academy, Ekaterinburg, (Russian Federation); Dubiel, S.M. [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow (Poland)

    2011-07-01

    Full text: Application of the Moessbauer spectroscopy with a high velocity resolution (4096 channels) for a study of iron-containing biological species is of great interest. Improving the velocity resolution allows to reveal small variations in the electronic structure of iron, and to obtain hyperfine parameters with smaller instrumental (systematic) errors in comparison with measurements performed in 512 channels or less. It also allows a more reliable fitting of complex Moessbauer spectra. In the present study the Moessbauer spectroscopy with the high velocity resolution was used for a comparative analysis of ferritin and its pharmaceutically important models as well as iron storage proteins in a chicken liver and a spleen. The ferritin, an iron storage protein, consists of a nanosized polynuclear iron core formed by a ferrihydrite surrounded by a protein shell. Iron-polysaccharide complexes contain {beta}-FeOOH iron cores coated with various polysaccharides. The Moessbauer spectra of the ferritin and commercial products Imferon, MaltoferR and Ferrum Lek as well as those of the chicken liver and spleen tissues were measured with the high velocity resolution at 295 and 90 K. They were fitted using two models: (1) with a homogeneous iron core (an approximation using one quadrupole doublet), and (2) with a heterogeneous iron core (an approximation using several quadrupole doublets). The model (1) can be used as the first approximation fit to visualize small variations in the hyperfine parameters. Using this model, differences in the Moessbauer hyperfine parameters were obtained in both 295 and 90 K Moessbauer spectra. However, this model was considered as a rough approximation because the measured Moessbauer spectra had non-Lorentzian line shapes. Therefore, the spectra of the ferritin, Imferon, MaltoferR and Ferrum Lek as well as those of the liver and spleen tissues were fitted again using the model (2) in which a different number of the quadrupole doublets was

  9. A Moessbauer study of doped magnetite

    International Nuclear Information System (INIS)

    Nistor, C.I.; Boekema, C.; Woude, F. van der; Sawatzky, G.A.

    1975-01-01

    Doped magnetite was investigated by means of the Moessbauer effect to ascertain the behaviour of conduction electrons in magnetite. The Moessbauer spectrum of Fe 3 O 4 recorded at room temperature consisted of two patterns: one corresponding to the Fe 3+ (A) ions and another corresponding to the Fe(B) ions. The first A and B lines of the room temperature Moessbauer spectra of Msub(0.1)Fesub(2.9)O 4 with M = Li, Ni and Sn are presented. The B site lines of the spectra were asymmetrically broadened and showed a certain structure whereas the A site lines were narrow. In the Moessbauer spectrum of Lisub(0.2)Fesub(2.8)O 4 recorded at 407 0 C even separate lines between the A and B patterns were observed. It was found that the symmetry and line broadening were only slightly temperature dependent and were still present at higher temperatures. The application of a charge oscillation model was found to be valid only for lower impurity concentrations. The Moessbauer study of doped magnetite revealed the occurrence of spin and charge density oscillations in the B sublattice. (Z.S.)

  10. Moessbauer spectroscopy study of a mineral sample from Oshno Hill, District of Chavin de Pariarca, Huanuco Region, Peru

    International Nuclear Information System (INIS)

    Bustamante, A.; Lovera, D.; Quille, R.; Arias, A. V.; Quinones, J.

    2010-01-01

    The analysis by X-ray diffraction of a mining sample collected from Oshno hill, which is located in the District of Chavin de Pariarca, Huamalies Province, Huanuco, Peru, indicates the presence of lepidocrocite (γ-FeOOH) and goethite (α-FeOOH). The room temperature Moessbauer spectrum (MS) doublet with broad lines displays hyperfine parameters corresponding to the presence of particles of iron hydroxides smaller than 100 A in a superparamagnetic regime. The measurement of a MS at 4.2 K allowed confirming the presence of goethite and lepidocrocite (with average magnetic fields of 49.21 T and 44.59 T, respectively).

  11. Study of reversible binding of molecular oxygen to cobalt(II) octaethylporphyrin by /sup 57/Co Moessbauer emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, H; Maeda, Y [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Ogoshi, H; Sugimoto, H; Yoshida, Z

    1978-04-01

    /sup 57/Co Moessbauer emission spectra of Co(II) octaethylporphyrin, Co(II) OEP, and its pyridine and oxygen adduct, Co(II) OEP.Py.O/sub 2/, have been measured in the dimethylformamide frozen solution at 20/sup 0/K. The former consists of two chemical species of Fe(II) OEP. The latter exhibits Fe(II) OEP.Py.O/sub 2/ and Fe(II) OEP.Py/sub 2/. The oxygenated complex is changed to the bis-pyridine adduct by evacuation at about -30/sup 0/C.

  12. Moessbauer and positron annihilation studies of microstructural peculiarities of iron-dextran complexes

    International Nuclear Information System (INIS)

    Oshtrakh, M.I.; Kopelyan, E.A.; Semionkin, V.A.; Livshits, A.B.; Kozlov, A.A.

    1995-01-01

    The microstructural peculiarities of pharmaceutically important iron-dextran complexes were studied by Moessbauer and positron annihilation techniques. The results of Moessbauer spectroscopy showed variations of the iron cores in iron-dextran complexes containing different forms of FeOOH and different electronic and magnetic states of iron. The results of angular correlations of annihilation radiation and positron life-time spectroscopies showed microstructural variations of the dextran shell of the iron-dextran complexes. (author) 19 refs.; 4 tabs

  13. Application of Moessbauer spectroscopy in studies of thermal fatigue of ceramic materials. Part of a coordinated programme on development of methods for the application of Moessbauer spectroscopy in mineralogy, soil sciences and ceramics

    International Nuclear Information System (INIS)

    Gangas, A.H.

    1980-10-01

    Moessbauer measurements have been carried out on powder samples of pseudobrookite (Fe 2 TiO 5 ) which is known to exhibit extensive microcracking due to its highly anisotropic thermal expansion. The samples were subjected to temperature cycling treatment either at high (30 to 450 C) or low (-130 to 120 C) temperature range. It was observed that the crystal lattice vibrations are changing in response to the thermal fatigue treatment applied. Measurements of isomer shift and Moessbauer spectral areas allows to determine the characteristic Debye temperature which depends on the type of temperature treatment used, the findings are in qualitative agreement with the existence of a critical grain size for the microcracking of Fe 2 TiO 5 as found in elastic modules and flexural strength measurements

  14. Moessbauer study of iron(III) salicylates

    Energy Technology Data Exchange (ETDEWEB)

    Mahesh, K; Sharma, N D; Gupta, D C [Kurukshetra Univ. (India). Dept. of Physics; Puri, D M [Kurukshetra Univ. (India). Dept. of Chemistry

    1979-07-01

    Moessbauer infrared and magnetic studies of different basic salicylates of iron(III) are reported. Comparison of observed isomer shift and quadrupole splitting with the earlier work allows to assign the trinuclear chain structure to the complexes wherein the central iron atom in the chain is considered to be octahedrally coordinated in case of salicylate and 4-aminosalicylate derivatives, and pentacoordinated for the thiosalicylate with the terminal iron atom in tetrahedral symmetry. The Moessbauer parameters and ..mu..sub(eff)-value indicate the high spin state of the central iron atom and low spin state for the terminal ones.

  15. Moessbauer firing study of Peruvian clays

    International Nuclear Information System (INIS)

    Salazar, R.; Wagner, U.; Wagner, F.E.

    1983-01-01

    In connection with work on ancient ceramics Moessbauer studies of the firing behaviour of six Peruvian clays have been performed in oxidizing and reducing atmospheres. For two clays, one of them is poor, the other one is rich in oxides, the change of the Moessbauer parameters on firing between 100 and 1350 0 C was measured in detail, both with and without preceding reduction. The minerals present at characteristic temperatures are determined by X-ray diffraction and an attempt is made to discuss the physical and chemical processes occurring in the different temperature ranges. (author)

  16. The experimental apparatus for synchrotron radiation Moessbauer spectroscopy of BL11 in SPring-8

    International Nuclear Information System (INIS)

    Mitsui, T.; Kitao, S.; Zhang, X.W.; Marushita, M.; Seto, M.

    2001-01-01

    Synchrotron radiation Moessbauer spectroscopy (time spectrum of nuclear forward scattering and nuclear resonant inelastic scattering) enables us to study both the electronic state and lattice dynamics of a target material. Furthermore, the excellent properties of synchrotron radiation (polarization, pulse, small beam size) promise us the unique studies for material science. In order to progress in these studies, some experimental apparatuses were installed in BL11XU of SPring-8

  17. Moessbauer study of iron uptake in cucumber root

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, K.; Kuzmann, E., E-mail: kuzmann@para.chem.elte.hu [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Fodor, F. [Eoetvoes Lorand University, Department of Plant Physiology and Molecular Plant Biology (Hungary); Vertes, A. [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Kamnev, A. A. [Russian Academy of Sciences, Institute of Biochemistry and Physiology of Plants and Microorganisms (Russian Federation)

    2005-09-15

    {sup 57}Fe Moessbauer spectroscopy was used to study the uptake and distribution of iron in the root of cucumber plants grown in iron-deficient modified Hoagland nutrient solution and put into iron-containing solution with 10 {mu}M Fe citrate enriched with {sup 57}Fe (90%) only before harvesting. The Moessbauer spectra of the frozen roots exhibited two Fe{sup 3+} components with typical average Moessbauer parameters of {delta} = 0.5 mm s{sup -1}, {Delta} = 0.46 mm s{sup -1} and {delta} = 0.5 mm s{sup -1}, {Delta} = 1.2 mm s{sup -1} at 78 K and the presence of an Fe{sup 2+} doublet, assigned to the ferrous hexaaqua complex. This finding gives a direct evidence for the existence of Fe{sup 2+} ions produced via root-associated reduction according to the mechanism proposed for iron uptake for dicotyledonous plants. Monotonous changes in the relative content of the components were found with the time period of iron supply. The Moessbauer results are interpreted in terms of iron uptake and transport through the cell wall and membranes.

  18. Thermal treatment of the Fe{sub 78}Si{sub 9}B{sub 13} alloy in it amorphous phase studied by means of Moessbauer spectroscopy; Tratamiento termico de la aleacion Fe{sub 78}Si{sub 9}B{sub 13} en su fase amorfa estudiado por medio de la espectroscopia Moessbauer

    Energy Technology Data Exchange (ETDEWEB)

    Cabral P, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Lopez, A.; Garcia S, F. [Facultad de Ciencias, UAEM, 50000 Toluca, Estado de Mexico (Mexico)

    2003-07-01

    The magnetic and microhardness changes, dependents of the temperature that occur in the Fe{sub 78}Si{sub 9}B{sub 13} alloy in it amorphous state were studied by means of the Moessbauer spectroscopy and Vickers microhardness. According to the Moessbauer parameters and in particular that of the hyperfine magnetic field, this it changes according to the changes of the microhardness; i.e. if the microhardness increases, the hyperfine magnetic field increases. The registered increment of hardness in the amorphous state of this alloy should be considered as anomalous, according to the prediction of the Hall-Petch equation, the one that relates negative slopes with grain sizes every time but small. (Author)

  19. A remote data acquisition and control system for Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Zhou Qingguo; Wang Li; Wang Yanlong; Zhao Hong; Zhou Rongjie

    2004-01-01

    A remote data acquisition and control system for Moessbauer spectroscopy based on an embedded computer with the Mini Real-Time Linux operating system is presented. This system can be accessed by an Internet browser or a Java application program, which is designed especially for this purpose. So controlling this system is simple and the interface is user friendly. The components of this system can easily be obtained. So it could be built in most laboratories. We have succeeded in designing and developing this system, as well as using the system at the Key Laboratory for Magnetism and Magnetic Material of Ministry of Education, Lanzhou University, PR China

  20. Moessbauer Studies in Chinese Archaeology: A Review

    International Nuclear Information System (INIS)

    Hsia Yuanfu; Huang Hongbo

    2003-01-01

    The Moessbauer effect has been applied to a wide variety of objects related to Chinese archaeology. Besides ceramic artifacts, materials like porcelain, glazes, bronzes, ancient coins, ancient mineral drugs, and even fossils were studied. This article reviews these applications with particular emphasis on the study of the famous terracotta warriors and horses of the Qin Dynasty.

  1. Moessbauer Studies in Chinese Archaeology: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Hsia Yuanfu; Huang Hongbo [Nanjing University, Department of Physics (China)

    2003-09-15

    The Moessbauer effect has been applied to a wide variety of objects related to Chinese archaeology. Besides ceramic artifacts, materials like porcelain, glazes, bronzes, ancient coins, ancient mineral drugs, and even fossils were studied. This article reviews these applications with particular emphasis on the study of the famous terracotta warriors and horses of the Qin Dynasty.

  2. Moessbauer study of hemoglobin of diabetes

    International Nuclear Information System (INIS)

    Li Aiguo; Ni Xinbo; Cai Yingwen; Zhang Guilin; Zhang Hongde; Ge Yongxin

    2000-01-01

    The hemoglobins from normal adults (Gly-Hb 5%), people infected with diabetes (Gly-Hb 10%) and serious diabetics (Gly-Hb 15%) were investigated by Moessbauer spectroscopy at liquid nitrogen temperature. All the experimental spectra of hemoglobin are composed of three doublets corresponding to oxy-hemoglobin (Oxy-Hb), deoxy-hemoglobin (Deoxy-Hb) and low-spin hemo-chrome (Ls-Hemo) respectively. It is found that Oxy-Hb is decreasing but Deoxy-hb increasing for diabetes. Experimental results also indicate that the line-width of Moessbauer spectra of Oxy-Hb for diabetics is narrower than that for normal adults, showing that while Fe on Oxy-Hb exists in pile-up of some similar states for normal adults, but it becomes in single state for serious diabetes

  3. Moessbauer spectroscopy evidence of intrinsic non-stoichiometry in iron telluride single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kiiamov, Airat G.; Tayurskii, Dmitrii A. [Institute of Physics, Kazan Federal University (Russian Federation); Centre for Quantum Technologies, Kazan Federal University (Russian Federation); Lysogorskiy, Yury V.; Vagizov, Farit G. [Institute of Physics, Kazan Federal University (Russian Federation); Tagirov, Lenar R. [Institute of Physics, Kazan Federal University (Russian Federation); E.K. Zavoisky Physical-Technical Institute, Russian Academy of Sciences, Kazan (Russian Federation); Croitori, Dorina [Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau (Moldova, Republic of); Tsurkan, Vladimir [Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau (Moldova, Republic of); Experimental Physics V, University of Augsburg (Germany); Loidl, Alois [Experimental Physics V, University of Augsburg (Germany)

    2017-04-15

    The FeTe parent compound for iron-superconductor chalcogenides was studied applying Moessbauer spectroscopy accompanied by ab initio calculations of electric field gradients at the iron nuclei. Room-temperature (RT) Moessbauer spectra of single crystals have shown asymmetric doublet structure commonly ascribed to contributions of over-stoichiometric iron or impurity phases. Low-temperature Moessbauer spectra of the magnetically ordered compound could be well described by four hyperfine-split sextets, although no other foreign phases different from Fe{sub 1.05}Te were detected by XRD and microanalysis within the sensitivity limits of the equipment. Density functional ab initio calculations have shown that over-stoichiometric iron atoms significantly affect electron charge and spin density up to the second coordination sphere of the iron sub-lattice, and, as a result, four non-equivalent groups of iron atoms are formed by their local environment. The resulting four-group model consistently describes the angular dependence of the single crystals Moessbauer spectra as well as intensity asymmetry of the doublet absorption lines in powdered samples at RT. We suppose that our approach could be extended to the entire class of Fe{sub 1+y}Se{sub 1-x}Te{sub x} compounds, which contain excess iron atoms. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Moessbauer spectroscopy system with increased performance and flexibility - utilization in material research

    International Nuclear Information System (INIS)

    Pechousek, J.; Novak, P.; Navarik, J.; Machala, L.

    2013-01-01

    Transmission Moessbauer Spectroscopy (TMS) is used for structural, phase, and magnetic characterization of mostly iron containing samples (commonly Fe, Sn, Ni, Zn, Eu etc.). Moessbauer Spectroscopy (MS) is a highly element selective method and in details it provides determination and quantification of phase composition of samples including amorphous and nanocrystalline; determination of valence and spin states of iron atoms, differentiation of structure positions of iron atoms, stoichiometry examination of cation substitution; magnetic state determination and local configuration of magnetic moments of the atoms; measurement of temperature dependences, measurement in external magnetic field; determination of magnetic properties including temperatures of magnetic transitions; and study of mechanism and kinetics of reactions in solid phase, phase transformations. (authors)

  5. Hyperfine magnetic fields of disorder systems by 57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Lipka, J.

    1994-01-01

    The feasibility of 57 Fe transmission Moessbauer spectroscopy in the study of hyperfine magnetic fields is described with emphasis on amorphous, nanocrystalline and quasicrystalline alloys. Distributions of hyperfine magnetic fields obtained are presented via three-dimensional projects where effects of sample composition, temperature and annealing time on magnetic structure are followed by changes in probability of the field values. This allows magnetic transitions as well as mixed electric-quadrupole and magnetic-dipole interactions to be observed

  6. Moessbauer study of Fe(III)-reducing sugar complexes

    International Nuclear Information System (INIS)

    Wolowiec, S.; Drabent, K.

    1985-01-01

    Iron(III) complexes with glucose, galactose, mannose and lactose were prepared. The Moessbauer and magnetic susceptibility data demonstrate the polymeric structure of the complexes. The thermal behaviour of the Fe(III)-glucose complex was monitored by Moessbauer spectroscopy. (author)

  7. The Application of Moessbauer Emission Spectroscopy to Industrial Cobalt Based Fischer-Tropsch Catalysts

    International Nuclear Information System (INIS)

    Loosdrecht, J. van de; Berge, P. J. van; Craje, M. W. J.; Kraan, A. M. van der

    2002-01-01

    The application of Moessbauer emission spectroscopy to study cobalt based Fischer-Tropsch catalysts for the gas-to-liquids process was investigated. It was shown that Moessbauer emission spectroscopy could be used to study the oxidation of cobalt as a deactivation mechanism of high loading cobalt based Fischer-Tropsch catalysts. Oxidation was observed under conditions that are in contradiction with the bulk cobalt phase thermodynamics. This can be explained by oxidation of small cobalt crystallites or by surface oxidation. The formation of re-reducible Co 3+ species was observed as well as the formation of irreducible Co 3+ and Co 2+ species that interact strongly with the alumina support. The formation of the different cobalt species depends on the oxidation conditions. Iron was used as a probe nuclide to investigate the cobalt catalyst preparation procedure. A high-pressure Moessbauer emission spectroscopy cell was designed and constructed, which creates the opportunity to study cobalt based Fischer-Tropsch catalysts under realistic synthesis conditions.

  8. Moessbauer and EXAFS spectroscopy investigation of iron and arsenic adsorption to lettuce leaves

    International Nuclear Information System (INIS)

    Vasconcelos, Igor F.; Silva, Gabriela C.; Carvalho, Regina P.; Dantas, Maria Sylvia S.; Ciminelli, Virginia S. T.

    2010-01-01

    The accumulation of iron and arsenic from aqueous solution by lettuce leaves biomass was investigated using Moessbauer and EXAFS spectroscopic techniques. Moessbauer spectroscopy results show that iron is oxidized during sorption while EXAFS results indicate that iron is coordinated by approximately 6 oxygen and 2 carbon atoms while arsenic is coordinated by approximately 4 oxygen atoms with iron as a second neighbor.

  9. Moessbauer and EXAFS spectroscopy investigation of iron and arsenic adsorption to lettuce leaves

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Igor F., E-mail: ifvasco@ufc.br [Universidade Federal do Ceara, Dep. Eng. Metalurgica e de Materiais (Brazil); Silva, Gabriela C.; Carvalho, Regina P.; Dantas, Maria Sylvia S.; Ciminelli, Virginia S. T. [Universidade Federal de Minas Gerais, Dep. Eng. Metalurgica e de Materiais (Brazil)

    2010-01-15

    The accumulation of iron and arsenic from aqueous solution by lettuce leaves biomass was investigated using Moessbauer and EXAFS spectroscopic techniques. Moessbauer spectroscopy results show that iron is oxidized during sorption while EXAFS results indicate that iron is coordinated by approximately 6 oxygen and 2 carbon atoms while arsenic is coordinated by approximately 4 oxygen atoms with iron as a second neighbor.

  10. A Moessbauer study on the photolysis of potassium trisoxalatoferrate(III) in solid and solutions

    International Nuclear Information System (INIS)

    Sato, H.; Tominaga, T.

    1977-01-01

    The photolysis of potassium trisoxalatoferrate(III) in solid and aqueous solutions was studied by Moessbauer spectroscopy. A ferrous species was mainly detected as an intermediate product in the photoirradiated solutions. A tentative mechanism was proposed for the overall reactions in and after the photolysis of this compound. The Moessbauer spectra were measured with a Hitachi AA-40 or Shimadzu MEG-2 Moessbauer spectrometer against Co-57 in copper foil. Acrylic holders (32 mm in diameter) were used for measurements of solutions: the irradiated solution was quickly frozen before measurement by adding it dropwise into the acrylic holder which had been cooled with liquid nitrogen or dry-ice. (T.I.)

  11. Moessbauer studies on ancient Chinese pottery of Yangshao Culture Period

    Energy Technology Data Exchange (ETDEWEB)

    Zhengfang, Yu; Qi, Zheng; Yufang, Zheng

    1988-02-01

    Eleven pieces of ancient Chinese pottery (4770 B.C. - 2960 B.C.) of Yangshao Culture Period collected from the Xi'an area have been studied by means of Moessbauer spectroscopy. The samples were refired up to 1100/sup 0/C in steps of 100/sup 0/C for 2 h in air. The highest temperature up to which the Moessbauer pattern remains basically unchanged can be identified with the original firing temperature. The result indicates that the firing temperatures for most of the sherds were between 900-1000/sup 0/C. The function of the grit contained in the pottery has been discussed. The crimson and reddish painted materials on the surface of sherds have been studied, respectively. The first appearance of pottery can probably be traced back to an even earlier period.

  12. Moessbauer studies on ancient Chinese pottery of Yangshao Culture Period

    International Nuclear Information System (INIS)

    Yu Zhengfang; Zheng Qi; Zheng Yufang; Zhongshan Univ., Guangzhou

    1988-01-01

    Eleven pieces of ancient Chinese pottery (4770 B.C. - 2960 B.C.) of Yangshao Culture Period collected from the Xi'an area have been studied by means of Moessbauer spectroscopy. The samples were refired up to 1100 0 C in steps of 100 0 C for 2 h in air. The highest temperature up to which the Moessbauer pattern remains basically unchanged can be identified with the original firing temperature. The result indicates that the firing temperatures for most of the sherds were between 900-1000 0 C. The function of the grit contained in the pottery has been discussed. The crimson and reddish painted materials on the surface of sherds have been studied, respectively. The first appearance of pottery can probably be traced back to an even earlier period. (orig.)

  13. Moessbauer spectroscopic studies of iron-storage proteins

    Energy Technology Data Exchange (ETDEWEB)

    St. Pierre, T.G.

    1986-01-01

    /sup 57/Fe Moessbauer spectroscopy was used to study iron storage proteins. Various cryostats and a superconducting magnet were used to obtain sample environment temperatures from 1.3 to 200K and applied magnetic fields of up to 10T. The Moessbauer spectra of ferritins isolated from iron-overloaded human spleen, limpet (Patella vulgata), giant limpet (Patella laticostata) and chiton (Clavarizona hirtosa) hemolymph, and bacterial (Pseudomonas aeruginosa) cells are used to gain information on the magnetic ordering- and superparamagnetic transition temperatures of the microcrystalline cores of the proteins. Investigations were made about the cause of the difference in the magnetic anisotropy constants of the cores of iron-overloaded human spleen ferritin and hemosiderin. Livers taken from an iron-overloaded hornbill and artificially iron-loaded rats showed no component with a superparamagnetic transition temperature approaching that of the human spleen hemosiderin.

  14. Disproportionation phenema of wistite phase in the model iron catalysts for ammonia synthesis studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Pattek-Janczyk, A.; Miczko, B.

    1990-01-01

    A model iron catalysts for ammonia synthesis containing a large amount of wustite (35 wt%) has been studied during the annealing in an inert atmosphere in the temperature range of 573-773 K. Changes in magnetite and wustite phases were followed by Muessbauer spectroscopy (MS). Before starting the thermal treatment, two kinds of wustite of different structures have been found by MS and X-ray diffraction. The behaviour of both kinds of wustite during the annealing was different. One of them, closer to the stoichiometric compound, disproportionated at once into magnetite and iron; its content decreased systematically without changes in the Muessbauer parameters. In the second wustite, only qualitatieve changes were observed at first (its nonstoichiometry decreases without changes in content and, next, this phase started to disproportionate too. (auhtor). 31 refs.; 6 figs.; 2 tabs

  15. Moessbauer spectroscopy studies of spin reorientations in amorphous and crystalline (Co0.2Fe0.8)72.5Si12.5B15 glass coated micro-wires

    International Nuclear Information System (INIS)

    Nowik, I.; Felner, I.; Garcia-Miquel, H.

    2007-01-01

    Thermo-gravimetric, differential scanning calorimetry and comprehensive 57 Fe Moessbauer spectroscopy studies of amorphous and crystalline ferromagnetic glass coated (Co 0.2 Fe 0.8 ) 72.5 Si 12.5 B 15 micro-wires have been recorded. The Curie temperature of the amorphous phase is T C (amorp) ∼730 K. The analysis of the Moessbauer spectra reveals that below 623 K the easy axis of the magnetization is axial-along the wires, and that a tangential or/and radial orientation occurs at higher temperatures. At 770 K, in the first 4 hours the Moessbauer spectrum exhibits a pure paramagnetic doublet. Crystallization and decomposition to predominantly α-Fe(Si) and Fe 2 B occurs either by raising the temperature above 835 K or isothermally in time at lower temperatures. Annealing for a day at 770 K, leads to crystallization. In the crystalline material the magnetic moments have a complete random orientation. After cooling back to ambient temperature, both α-Fe(Si) and Fe 2 B in the glass coated wire show pure axial magnetic orientation like in the original amorphous state. The observed spin reorientations are associated with changes in the stress induced by the glass coating

  16. Characterization of Maghsail meteorite from Oman by Moessbauer spectroscopy, X-ray diffraction and petrographic microscopy

    International Nuclear Information System (INIS)

    Al-Rawas, A. D.; Gismelseed, A. M.; Al-Kathiri, A. F.; Elzain, M. E.; Yousif, A. A.; Al-Kathiri, S. B.; Widatallah, H. M.; Abdalla, S. B.

    2008-01-01

    The meteorite found at Maghsail (16 55 70 N-53 46 69 E) west of Salalah Oman, has been studied by 57 Fe Moessbauer spectroscopy, X-diffractometry and petrographic microscopy. In the polished section the meteorite exhibits a porphyritic texture consisting of pyroxene and olivine phenocrysts in a fine to medium grained ground mass in addition to minor phases possibly skeletal chromite, troilite and minute amount of iron oxides. X-ray diffraction supports the existence of these compounds. The Moessbauer spectra of powdered material from the core of the rock at 298 K and 78 K exhibit a mixture of magnetic and paramagnetic components. The paramagnetic components are assigned to the silicate minerals olivine and pyroxene. On the other hand, the magnetic spectra reveal the presence of troilite and iron oxides. The petrographic analyses indicate that the iron oxides are terrestrial alteration products.

  17. Mineral identification in Colombian coals using Moessbauer spectroscopy and X-ray diffraction

    International Nuclear Information System (INIS)

    Fajardo, M.; Mojica, J.; Barraza, J.; Perez Alcazar, G.A.; Tabares, J.A.

    1999-01-01

    Minerals were identified in three Colombian coal samples from the Southwest of the country using Moessbauer spectroscopy and X-ray diffraction. Original and sink separated coal fractions of specific gravity 1.40 and 1.60 with particle size less than 600 μm were used in the study. Using Moessbauer spectroscopy, the minerals identified in the original coal samples were pyrite jarosite, ankerite, illite and ferrous sulfate, whereas by means of X-ray diffraction, minerals identified were kaolinite, quartz, pyrite, and jarosite. Differences in mineral composition were found in the original and sink separated fractions using both techniques. Moessbauer spectra show that the mineral phases in low concentrations such as illite, ankerite and ferrous sulfate do not always appear in the spectra of sink coals, despite of those minerals occurring in the original coal, due to the fact that they are associated with the organic matter and not liberated in the grinding process. X-ray results show that the peak intensity grows as the specific gravity is increased indicating that the density separation method could be an effective process to clean coal

  18. Moessbauer Studies of Implanted Impurities in Solids

    CERN Multimedia

    2002-01-01

    Moessbauer studies were performed on implanted radioactive impurities in semiconductors and metals. Radioactive isotopes (from the ISOLDE facility) decaying to a Moessbauer isotope were utilized to investigate electronic and vibrational properties of impurities and impurity-defect structures. This information is inferred from the measured impurity hyperfine interactions and Debye-Waller factor. In semiconductors isoelectronic, shallow and deep level impurities have been implanted. Complex impurity defects have been produced by the implantation process (correlated damage) or by recoil effects from the nuclear decay in both semiconductors and metals. Annealing mechanisms of the defects have been studied. \\\\ \\\\ In silicon amorphised implanted layers have been recrystallized epitaxially by rapid-thermal-annealing techniques yielding highly supersaturated, electrically-active donor concentrations. Their dissolution and migration mechanisms have been investigated in detail. The electronic configuration of Sb donors...

  19. Moessbauer Spectroscopy at the University of Dar Es Salaam

    International Nuclear Information System (INIS)

    Kiwanga, C.A.

    1989-01-01

    A recently acquired facility for Moessbauer spectroscopy is described. Test results on samples of an iron ore and a steel corrosion product are given. It is deduced that the iron ore contained hematite (alpha-Fe203) constituting 41.5%, magnetite (Fe 304) constituting of 39.5% and two doublet phases: a paramagnetic Fe 3+ phase constituting 4.8% and a paramagnetic Fe 2+ phase constituting 14.2%. The steel corrosion product seems to be entirely composed of lepidocrocite (gamma-FeOOH). The results obtained are in excellent agreement with the literature data with regard to the identified iron compounds. It is concluded that the facility including the data processing computer programs which are essentially home-made is capable of producing very high quality research findings. (author)

  20. Investigation of microbial-mineral interactions by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brown, D.A.

    1998-01-01

    Moessbauer spectroscopy was used to investigate the reactions of microbes with iron minerals in aqueous solutions and as components of rocks in banded iron formations and granite. A microbial biofilm that formed on a wall of an excavated granite vault in a deep underground laboratory initiated this research. At the aerobic face of the biofilm, iron was found in a form of ferrihydrite; in the anaerobic face against the rock, iron was found as very small siderite particles. Laboratory incubations of the biofilm microbial consortium showed different mineral species could be formed. When the microbial consortium from the biofilm was incubated with magnetite grains, up to about 10% of the iron was altered in three weeks to hematite. The ability of the consortium to precipitate iron both as Fe 2+ and Fe 3+ in close proximity may have a bearing on the deposition of banded iron formations. These reactions could also be important in microbially induced corrosion

  1. Moessbauer Study of Soil Profiles in Industrial Region of Ukraine

    International Nuclear Information System (INIS)

    Kopcewicz, B.; Jelenska, M.; Hasso-Agopsowicz, A.; Kopcewicz, M.

    2005-01-01

    Moessbauer spectroscopy was applied to study the influence of industrial activity on soil composition. Comparing the Moessbauer spectra of separate layers for the Mariupol sampling site (highly polluted industrial region of South -- East Ukraine) we observed: i) appearance of the Fe3O4 compound at top soil layers: 16.6% of relative spectral area (RA) at (0 - 10 cm) layer, 5.3% of RA at (30 - 40 cm) layer and no magnetite component at deeper layers, ii) a significant increase of the contribution of the magnetically split spectral components: from 10.9% of RA for (120 - 130 cm) layer to 32.8% of RA for (0-10 cm) layer. The differences in RA of the magnetically split spectral components between top soil layer and the (120 - 130 cm) layer at the Homutovski steppe sampling site (non-polluted area) are much smaller, 13.7% and 9.8%, respectively. From the temperature dependence of the Moessbauer spectra it was concluded that part of the iron-containing compounds appears in the form of ultra fine particles in the superparamagnetic state. The observed increase of total concentration of the magnetic minerals for polluted sampling sites is caused by an increase of the content of coarse fraction of the magnetic particles

  2. Characterization of laves phases in the pseudobinary Zr Cr2-Zr Fe2 system by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Kanter, F.L. de; Badler, C.S.; Granovski, M.; Arias, D.

    1988-01-01

    57 Fe Moessbauer spectroscopy together with XRD and optical metallography were used to verify the two phase boundaries of the ZrCr 2 -ZrFe 2 pseudobinary phase diagram. Samples with adequate ternary and binary composition, treated at 1450 0 C, were studied. Experimental results indicate that in some cases the two phase boundaries should be modified. (author)

  3. Selective Dissolution Techniques, X-Ray Diffraction and Moessbauer Spectroscopy Studies of Forms of Fe in Particle-Size Fractions of an Entic Haplustoll

    International Nuclear Information System (INIS)

    Acebal, S. G.; Aguirre, M. E.; Santamaria, R. M.; Mijovilovich, A.; Petrick, S.; Saragovi, C.

    2003-01-01

    Particle-size fractions (o = mean diameter, 5-2 μm, 2-1 μm, and 57 Fe Moessbauer spectroscopy (MS). Quartz, feldspar, smectite, illite and interstratified illite-smectite are the dominant minerals whereas Fe oxides and oxy-hydroxides are present in low concentration but increase as particle size decreases. Poorly crystallized oxides (highly Al-substituted hematite and goethite) amounts are lower, comparable to or slightly higher than the hematite amounts in the o 5-2 μm, 2-1 μm and 3+ and Fe 2+ are associated to the clay minerals and/or hydroxyl-interlayered 2:1 type material present; part of this Fe 3+ is located in the hydroxy-interlayers its amount being higher in the smallest fraction. Any possible changes after the PY and NaOH treatments were not detected by MS.

  4. XRD and 119Sn Moessbauer spectroscopy characterization of SnSe obtained from a simple chemical route

    International Nuclear Information System (INIS)

    Bernardes-Silva, Ana Claudia; Mesquita, A.F.; Moura de Neto, E.; Porto, A.O.; Ardisson, J.D.; Lima, G.M. de; Lameiras, F.S.

    2005-01-01

    Crystalline tin selenide semiconductor was synthesized by a chemical route. Selenium powder reacted with potassium boronhydride, giving a soluble selenium species potassium seleniumhydride. The reaction of potassium seleniumhydride with tin chloride produced crystalline tin selenide, which was characterized by X-ray diffraction, 119 Sn Moessbauer spectroscopy and scanning electronic microscopy. The material was thermally treated, in nitrogen flow, at 300 and 600 deg. C for 2 h and the particle size evolution was studied by X-ray diffraction. The X-ray diffraction and 119 Sn Moessbauer results showed that a mixture of tin oxides and orthorhombic tin selenide was obtained

  5. Moessbauer and NMR study of novel Tin(IV)-lactames

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, Erno; Szalay, Roland; Homonnay, Zoltan, E-mail: homonnay@ludens.elte.hu; Nagy, Sandor [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2012-03-15

    N-tributylstannylated 2-pyrrolidinone was reacted with tributyltin triflate in different molar ratios and the complex formation monitored using {sup 1}H-NMR, {sup 13}C-NMR and {sup 119}Sn Moessbauer spectroscopy. Comparing the carbon NMR and tin Moessbauer results, a reaction scheme is suggested for the complexation which assumes the formation of a simultaneously O- and N-tributylstannylated pyrrolidinone cation. The formation of the only O-stannylated pyrrolidinone is also assumed to account for the non-constant Moessbauer parameters of the two tin environments in the distannylated pyrrolidinone cation when the ratio of tributyltin triflate is increased in the reaction.

  6. 57Fe Moessbauer Studies in Mo-Fe Supported Catalysts

    International Nuclear Information System (INIS)

    Castelao-Dias, M.; Costa, B. F. O.; Quinta-Ferreira, R. M.

    2001-01-01

    Industrially, the Mo-Fe catalysts used in the selective oxidation of methanol to formaldehyde can rapidly deactivate. The use of support materials may reduce the high temperatures in the catalytic bed and/or increase thermal and mechanical resistance. However, during the preparation of these catalysts, or even during reaction conditions, the active species may react with the support material losing their catalytic activity. In this work silica, silicium carbide and titania were studied as supported catalysts by Moessbauer spectroscopy which proved to be a useful technique in the choice of supported materials

  7. Moessbauer Study of Discoloration of Synthetic Resin Covered Electric Switches

    International Nuclear Information System (INIS)

    Kuzmann, E.; Muzsay, I.; Homonnay, Z.; Vertes, A.

    2002-01-01

    57 Fe Moessbauer spectroscopy and X-ray diffractometry were used to investigate brown discoloration and sediments formed on the surface of synthetic resin product covered electronic switches. The Moessbauer measurement revealed that alloyed steels and iron-containing corrosion products are associated with the discolored layers. Iron, and iron corrosion products were shown by both MS and XRD in the sediments formed eventually during the finishing of the synthetic resin products after machining and washing with water solution.

  8. Moessbauer study of the chemical state of gold in gold ores

    International Nuclear Information System (INIS)

    Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

    1986-01-01

    Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

  9. Moessbauer studies of superparamagnetic ferrite nanoparticles for functional application

    Energy Technology Data Exchange (ETDEWEB)

    Mazeika, K., E-mail: kestas@ar.fi.lt; Jagminas, A.; Kurtinaitiene, M. [SSRI Center for Physical Sciences and Technology (Lithuania)

    2013-04-15

    Nanoparticles of CoFe{sub 2}O{sub 4} and MnFe{sub 2}O{sub 4} prepared for functional applications in nanomedicine were studied using Moessbauer spectrometry. Superparamagnetic properties of nanoparticles of different size and composition were compared applying collective excitations and multilevel models for the description of the Moessbauer spectra.

  10. Phase analysis of superconducting Nb-Sn materials by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Tomasich, M.; Cirak, J.; Prejsa, M.; Kruzliak, J.

    1978-01-01

    Moessbauer spectroscopy is used for the optimalization of superconducting Nb-Sn samples preparation in the form of foils. Pure phases of Nb 3 Sn, Nb 6 Sn 5 , and NbSn 2 are determined. Two series of samples are studied at 750 and 900 0 C tinning temperature respectively, and at 750, 860, 900, and 960 0 C heating temperatures. In the samples the phases Nb 3 Sn, Nb 6 Sn 5 , NbSn 2 , and the solid solution Nb-Sn phase are observed. The results from the phase analysis lead to the assumption that the percentage amount of the phases is preferentially dependent on the tinning temperature. (author)

  11. Moessbauer spectroscopy of some volcanic glasses from the Pampa Region, Cordoba, Argentina

    International Nuclear Information System (INIS)

    Saragovi-Badler, C.; Labenski, F.

    1987-01-01

    Moessbauer spectroscopy was applied to the study of volcanic glasses and closely associated clay minerals which were carefully separated from the sediments of the Pampa Region. The parameters of volcanic glass samples show the presence of a high content of Fe 2+ in octahedral coordination and some Fe 3+ in tetrahedral and octahedral coordination. No remarcable difference was found comparing with a 'pure' volcanic glass sample taken as a reference. In the clay samples the only clay mineral found was illite. (author) 7 refs

  12. Analysis of iron state in some Argentinian soils by dissolution methods and Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Venegas, R.; Labenski de Kanter, F.; Acebal, S.; Grassi, R.; Rueda, E.H.; Aguirre, M.E.; Saragovi, C.

    1994-01-01

    Bahia Blanca (Argentina) soils, in particular entisols, are studied by Moessbauer spectroscopy. X-ray diffraction and scanning electron microscopy are used to characterize the samples. Samples were treated with different chemical iron extraction methods, in order to determine relative Fe o and Fe d fractions. The Fe o /Fe d ratios are obtained and the relative effect of iron extraction treatment on spectra components are determined. In addition, the effect of extraction procedures, dithionite-citrate-bicarbonate and oxalate, in the residual soil fraction are analyzed. (orig.)

  13. Moessbauer studies of a martensitic transformation and of cryogenic treatments of a D2 tool steel

    Energy Technology Data Exchange (ETDEWEB)

    Costa, B. F. O., E-mail: benilde@ci.uc.pt [University of Coimbra, CEMDRX, Department of Physics (Portugal); Blumers, M. [University Mainz, Institute of Inorganic Chemistry (Germany); Kortmann, A. [Ingpuls GmbH (Germany); Theisen, W. [Ruhr-Universitaet Bochum, Institute of Materials (Germany); Batista, A. C. [University of Coimbra, CEMDRX, Department of Physics (Portugal); Klingelhoefer, G. [University Mainz, Institute of Inorganic Chemistry (Germany)

    2013-04-15

    A D2 tool steel X153CrVMo12 with composition C1.53 Cr12 V0.95 Mo0.80 Mn0.40(wt% Fe balanced) was studied by use of Moessbauer spectroscopy and X-ray diffraction. It was observed that the study of carbides by X-ray diffraction was difficult while Moessbauer spectroscopy gives some light on the process occurring during cryogenic treatment. With the increase of the martensitic phase the carbides decrease and are dissolved in solid solution of martensite as well as the chromium element.

  14. Moessbauer study of magnetic properties of KFeF3

    International Nuclear Information System (INIS)

    Ito, A.; Morimoto, S.

    1975-01-01

    The results of the Moessbauer study of magnetic properties of KFeF 3 in a temperature range of 4.2 to 300 K are reported. Powdered and single crystal samples were used as absobers. Moessbauer spectra obtained for the powdered samples at various temperatures, for the single crystal with axial stress along the [111] direction obtained at 77 and 4.2 K and temperature dependences of the Moessbauer parameters are presented. The magnetic properties of KFeF 3 were found to be very sensitive to strain. The effect of strain was found to be significant near the Neel temperature and 40 K. Tsub(N) was determined by the Moessbauer study to be 112 K for the single-crystal-free and 117 K for the single-crystal-(111)-fixed sample. The Moessbauer spectra near Tsub(N) are given. (Z.S.)

  15. Thermal Transformations of Iron Cations in the System Metal-Vitreous Enamel Coat. Moessbauer Spectroscopic Study

    International Nuclear Information System (INIS)

    Barcova, K.; Mashlan, M.; Zboril, R.; Hrabovska, K.

    2005-01-01

    Vitreous enameling on steel is carried out to provide a protective layer against chemical corrosion from the surrounding environment. The glass bonds with the steel to form a composite material. The Moessbauer spectroscopy was firstly applied to study the vitreous enameling in which the complex of processes, as diffusion of species, adhesion between the glass and the steel, galvanic reactions, plays an important role. The Moessbauer spectroscopy provides unique information about the Fe-phase structure of the vitreous enamel layer and that of the steel-enamel interface. Diffusion of iron from steel surface towards enamel layer and formation of a new Fe2+ phase was proved

  16. Isomeric shift compensation when using resonance detectors in Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Irkaev, S.M.; Semenkin, V.A.; Sokolov, M.M.

    1981-01-01

    Method for compensation of isomeric shift of lines observed during operation of resonance detectors being part of spectrometers of nuclear gamma resonance is suggested. A flowsheet of device permitting to realize the method described is given. The method is based on using the Doppler effect. A source of resonance radiation is moved at a constant velocity, which is choosen so as to compensate energy shift of lines of the source and convertors of the resonance detector. The absorber under investigation is put in motion with a constant acceleration. The resonance detector signals are amplified selected according to amplitude by a discriminator and come to the input of multichannel analyzer operating in the regime of subsequent scaling. Analysis of experimental spectra obtained at velocities of source movement from 0 to +3 mm/s shows that value of resonance absorption effect drops as increasing energy shift in the source-converter system. It is concluded that application of the method described will permit to considerably extend the field of application of resonance detectors in the Moessbauer spectroscopy and investigate in practice all the isotopes having converted transitions [ru

  17. Proceedings of the 1. National Meeting of Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    1982-01-01

    Several works, both theoretical and experimental, on Moessbauer effect which have been done by Brazilian physical groups are presented in this meeting. The historical evolution of this field in Brazil is also approached. (L.C.) [pt

  18. Compact cryogenic attachment for Moessbauer spectroscopy with microwave excitation

    International Nuclear Information System (INIS)

    Didenko, N.P.; Amelin, G.P.; Zelentsov, V.I.; Kaminskii, V.L.; Fedorov, N.P.; Fal'kovich, V.M.

    1989-01-01

    A compact cryogenic attachment is described that is placed on a standard helium Dewar flask and permits recording of Moessbauer spectra with excitation by millimeter-band radiation in the temperature range of 4.3-300 K. The design of the attachment allows operation with various gamma-radiation detectors in both horizontal and vertical Moessbauer measurement geometries and its placement in superconducting magnets with a large warm zone

  19. Study of Phase Transformations on Nano-Crystalline (La,Sr)(Mn,Fe)O3 Systems by High-Pressure Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Chandra, Usha; Mudgal, Prerana; Kumar, Manoj

    2006-01-01

    We report pressure-dependent 57Fe Moessbauer studies on a nano-crystalline perovskite La0.8Sr0.2(Mn0.8Fe0.2) O3 system up to 10 GPa using diamond anvil cell. At ambient pressure, iron is present as Fe3+ and Fe4+ in two different environments. Pressure seems to affect the higher symmetry site of Fe4+, while the octahedral site containing Fe3+ remains almost unaffected. Phase transformations are observed at pressures 0.52 GPa and 3.7 GPa respectively. A sudden increase in the isomer shift at 0.52 GPa is related to the reduction of Fe4+ ions while at 3.7 GPa, a structural transition is observed with sudden drop in isomer shift indicating Fe3+ ions in identical environment. Quadrupole splittings increase continuously with pressures up to 10 GPa

  20. Early Pottery Making in Northern Coastal Peru. Part I: Moessbauer Study of Clays

    International Nuclear Information System (INIS)

    Shimada, I.; Haeusler, W.; Hutzelmann, T.; Wagner, U.

    2003-01-01

    We report on an investigation of several ancient clays which were used for pottery making in northern coastal Peru at a kiln site from the Formative period (ca. 2000-800 BC) in the Poma Canal and at a Middle Sican pottery workshop in use between ca. AD 950 and 1050 at Huaca Sialupe in the lower La Leche valley. Neutron activation analysis, 57 Fe Moessbauer spectroscopy and X-ray diffraction were used for the characterisation of the clays. The changes that occur in iron-bearing compounds in the clays depending on the kiln atmosphere and on the maximum firing temperature were studied by Moessbauer spectroscopy and X-ray diffraction. Laboratory firing series under varying controlled conditions were performed to obtain a basic understanding of the different reactions taking place in the clays during firing. The results can be used as models in the interpretation of the Moessbauer spectra observed in ancient ceramics from the same context.

  1. Moessbauer studies of non-linear excitations and gold cluster compounds

    International Nuclear Information System (INIS)

    Smit, H.H.A.

    1988-01-01

    Moessbauer effect spectroscopy has been applied to the study of three polynuclear gold cluster compounds. The resulting information on the local vibrational density of states has been compared to several models which take the finite size of the particles into consideration. 188 refs.; 34 figs.; 103 schemes; 8 tabs

  2. Moessbauer spectroscopy of He irradiated austenitic stainless steel SUS304 at low temperature

    International Nuclear Information System (INIS)

    Horii, Kiyomasa; Ishibashi, Tetsu; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi; Kawasaki, Katsunori; Hayashi, Nobuyuki; Sakamoto, Isao.

    1996-01-01

    SUS 304 austenitic stainless steel causes the magnetic transition at 60 K, and the Young's modulus lowers. In addition, its composition elements have the large (n,α) reaction cross section to high energy neutrons, and helium is apt to be generated, and this is a factor that lowers the material strength. In the He-irradiated parts in austenitic stainless steel, the precursory state of martensite transformation should exist, and its effect is considered to be observable by carrying out low temperature Moessbauer spectroscopy. As to the preparation of He-irradiation samples, the SUS 304 foils used and the irradiation conditions are described. The measurement of low temperature Moessbauer spectra for the samples without irradiation and with irradiation is reported. In order to determine the magnetic transition point, the thermal scanning measurement was carried out for the samples without or with irradiation. The martensite transformation was measured by X-ray diffraction and transmission type Moessbauer spectroscopy. In order to observe the state of the sample surfaces, the measurement by internal conversion electron Moessbauer spectroscopy was performed. These results and the temperature dependence of the Moessbauer spectra for the irradiated parts are reported. (K.I.)

  3. Moessbauer spectroscopy of He irradiated austenitic stainless steel SUS304 at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Horii, Kiyomasa; Ishibashi, Tetsu; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi [Musashi Inst. of Tech., Tokyo (Japan); Kawasaki, Katsunori; Hayashi, Nobuyuki; Sakamoto, Isao

    1996-04-01

    SUS 304 austenitic stainless steel causes the magnetic transition at 60 K, and the Young`s modulus lowers. In addition, its composition elements have the large (n,{alpha}) reaction cross section to high energy neutrons, and helium is apt to be generated, and this is a factor that lowers the material strength. In the He-irradiated parts in austenitic stainless steel, the precursory state of martensite transformation should exist, and its effect is considered to be observable by carrying out low temperature Moessbauer spectroscopy. As to the preparation of He-irradiation samples, the SUS 304 foils used and the irradiation conditions are described. The measurement of low temperature Moessbauer spectra for the samples without irradiation and with irradiation is reported. In order to determine the magnetic transition point, the thermal scanning measurement was carried out for the samples without or with irradiation. The martensite transformation was measured by X-ray diffraction and transmission type Moessbauer spectroscopy. In order to observe the state of the sample surfaces, the measurement by internal conversion electron Moessbauer spectroscopy was performed. These results and the temperature dependence of the Moessbauer spectra for the irradiated parts are reported. (K.I.)

  4. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    International Nuclear Information System (INIS)

    Jaen, Juan A.; Navarro, Cesar

    2009-01-01

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  5. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Depto. de Quimica Fisica, CITEN, Lab. No. 105, Edificio de Laboratorios Cientificos-VIP (Panama); Navarro, Cesar [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2009-07-15

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  6. Using Moessbauer spectroscopy as key technique in the investigation of nanosized magnetic particles for drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Morais, P. C., E-mail: pcmor@unb.br [Universidade de Brasilia, Nucleo de Fisica Aplicada, Instituto de Fisica (Brazil)

    2008-01-15

    This paper describes how cobalt ferrite nanoparticles, suspended as ionic or biocompatible magnetic fluids, can be used as a platform to built complex nanosized magnetic materials, more specifically magnetic drug delivery systems. In particular, the paper is addressed to the discussion of the use of the Moessbauer spectroscopy as an extremely useful technique in supporting the investigation of key aspects related to the properties of the hosted magnetic nanosized particle. Example of the use of the Moessbauer spectroscopy in accessing information regarding the nanoparticle modification due to the empirical process which provides long term chemical stability is included in the paper.

  7. TEM and Moessbauer Study of Nano Sized Fe2MnAl Flakes

    International Nuclear Information System (INIS)

    Vinesh, A.; Sudheesh, V. D.; Lakshmi, N.; Venugopalan, K.

    2011-01-01

    Magnetic and structural properties of L21 ordered Fe 2 MnAl Heusler alloy have been studied by X-ray diffraction, Transmission electron microscopy (TEM), Moessbauer spectroscopy and DC magnetization. Structural texturing induced by ball milling is destroyed on heating while Moessbauer and DC magnetization studies show magnetic texturing persists after thermal treatment. TEM shows large distribution in particle size with an average size of 27 nm. Thermal annealing of ball milled sample results L2 1 ordering and the needle shaped particle contributes spin texturing.

  8. Lattice dynamics of intercalation and layer compounds by 119Sn Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Herber, R.H.; Davis, R.F.

    1976-01-01

    Gamma ray resonance spectroscopy using the 28-keV radiation from 119 Sn was employed to study the lattice dynamics of layer compounds and their metal atom intercalates. It was found that in solids in which the ( 119 Sn) Moessbauer atom is held either as an ion or as an isolated atom in the structure, both the characteristic lattice temperature (THETA/sub M/) value calculated from the temperature dependence of the recoil-free fraction (evaluated in the high temperature limit where T is greater than THETA/2 and in the absence of significant anharmonic effects) and characteristic temperature (THETA/sub CT/) value calculated by the Craig-Taylor procedure give internally consistent values for the lattice temperature of the solid as probed by the Moessbauer atom. In cases where this probe atom is part of a covalently bonded structure, as for example in the extended polymeric SnS 2 , SnSe 2 and related solids, the difference between THETA/sub M/ and THETA/sub CT/ will be significant, and this difference should be useful in the elucidation of the intermolecular and bonding forces in such solids and their relationship to the solid state properties of these materials. It is noted that the experimental determination of a unique lattice temperature by Moessbauer spectroscopic methods provides the solid state physicist with an additional parameter which should be useful in the characterization of solids, and, more importantly, may serve as a diagnostic tool in the assessment of the effects of systematic changes (such as, for example, compositional variations, radiation damage effects, implantation, and intercalation consequences) brought about in such materials

  9. High resolution Moessbauer spectroscopy with 67Zn in metallic systems

    International Nuclear Information System (INIS)

    Potzel, W.

    1985-01-01

    Moessbauer experiments on metallic systems are described where the high resolution 93.3 keV resonance in 67 Zn is used. In the first part, the Cu-Zn alloy system is investigated and the high energy resolution of this Moessbauer transition is employed to determine small changes of the s-electron density at the 67 Zn nucleus when the Zn concentration is changed. In the second part, Zn metal is taken as an example to demonstrate that the 93.3 keV transition is also extremely sensitive to small changes of lattice dynamical effects. 7 refs., 18 figs. (author)

  10. Moessbauer spectroscopic studies of alkylammonium iron(III) complexes

    International Nuclear Information System (INIS)

    Katada, M.; Kozawa, S.; Nakajima, Y.

    2006-01-01

    Alkylammonium iron(III) complexes, [(n-C n H 2n+1 )mNH 4-m ] 3 [Fe(CN) 6 ] were prepared and studied by Moessbauer spectroscopy, XRD, and DSC. In the complexes with m=2, the temperature dependences of the area intensity of Moessbauer are correlated to the motion of alkyl chains. The temperature dependence of the complex with n=4 was linear and smaller than that of other complexes. Especially in the complex with n=6, the deviation from the linear was the largest in the complexes observed. This result is attributed to the structural difference of the complex. The complexes with n≥8 consist of two-dimensional layer structure. The temperature dependence of the area intensity was similar to each other. This means that the motion of alkyl chain in these complexes are almost the same. The values of quadrupole splitting for the complexes were larger those that of the complexes (m=1). This indicates that the form of [Fe(CN) 6 ] 3- ion is affected by the differences of the number of alkyl groups. (author)

  11. Moessbauer spectroscopy at the 93.3 KeV gamma transition at Zn-67

    International Nuclear Information System (INIS)

    Forster, A.

    1981-01-01

    This work presents the result of a Moessbauer effect study at the zinc-67 isotope. The 93.3 KeV gamma transition has the highest energy resolution of all accessible Moessbauer transitions. Source and absorber we cooled down to 4.2 K. The aim of the examination was 1) development of a method for solid state physical measuring of Moessbauer-resonances with high resolution and 2) to test this method to study the hfs parameters for ZnO, ZnS, ZnSe, ZnTe and ZnF 2 . (KHF)

  12. Study on Moessbauer spectra of hemoglobin in thalassemia

    International Nuclear Information System (INIS)

    Guo Xuanhui; Zhao Nanming; Zhang Xiufang

    1988-01-01

    The 57 Fe Moessbauer spectra of erythrocytes in normal subjects and nine patients of different thalassemias were studied. Together with clinical analysis, the correlation between the components in the spectra and different types of anemias was discussed. (orig.)

  13. Moessbauer study of Fe-Co nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou (China)]. E-mail: chenzy@lzu.edu.cn; Zhan Qingfeng; Xue Desheng; Li Fashen [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou (China); Zhou Xuezhi; Kunkel, Henry; Williams, Gwyn [Department of Physics and Astronomy, the University of Manitoba (Canada)

    2002-01-28

    Arrays of Fe{sub 1-x}Co{sub x} (0.0{<=}x{<=}0.92) nanowires have been prepared by an electrochemical process, co-depositing Fe and Co atoms into the pores of anodic aluminium; their compositions were determined by atomic absorption spectroscopy. Transmission electron microscope results show that the nanowires are regularly spaced and uniform in shape with lengths of about 7.5 {mu}m and diameters of 20 nm. The x-ray diffraction indicates a texture in the deposited nanowires. For the composition below 82 at.% cobalt, the nanowires had a body-centred-cubic structure with a [110] preferred orientation. For the 92 at.% cobalt sample, the alloy exhibited a mixture of bcc and face-centred-cubic structure. The room temperature {sup 57}Fe Moessbauer spectra of the arrays of Fe{sub 1-x}Co{sub x} nanowires have second and fifth absorption lines of the six-line pattern with almost zero intensity, indicating that the internal magnetic field in the nanowires lies along the long axis of the nanowire. The maximum values of the hyperfine field (B{sub hf} 36.6{+-}0.1 T) and isomer shift (IS=0.06{+-}0.01 mm s-1) occur for 44 at.% cobalt. The variations of the isomer shift and the linewidths with composition indicate that the Fe{sub 1-x}Co{sub x} alloy nanowires around the equiatomic composition are in an atomistic disordered state. (author)

  14. Reducing firing of an early pottery making kiln at Batan Grande, Peru: A Moessbauer study

    International Nuclear Information System (INIS)

    Wagner, U.; Gebhard, R.; Haeusler, W.; Hutzelmann, T.; Riederer, J.; Shimada, I.; Sosa, J.; Wagner, F.E.

    1999-01-01

    Material from field firing experiments using a 2,700-year old Formative kiln at Batan Grande, Peru, was studied by X-ray diffraction and Moessbauer spectroscopy. The experiments explore the technology involved in producing the gray and black reduced ware for which Cupisnique and other Formative ceramics are justly known. During firing, the iron-bearing compounds in clays undergo characteristic changes which depend on kiln temperature and atmosphere. These changes can be observed in the Moessbauer spectra. By comparing spectra of an appropriate clay fired in field experiments and in the laboratory with the spectra of ancient ceramics, a description of Formative firing techniques in a reducing environment is attempted

  15. Moessbauer Spectroscopic Study of a Mural Painting from Morgadal Grande, Mexico

    International Nuclear Information System (INIS)

    Kuno, A.; Matsuo, M.; Soto, A. Pascual; Tsukamoto, K.

    2004-01-01

    In this study, 57 Fe Moessbauer spectroscopy has been applied to fragments of a mural painting excavated at Morgadal Grande, Mexico, to characterize the pigments used. A sextet attributable to hematite (α-Fe 2 O 3 ) was clearly detected in the red fragments. The spectra of orange fragments showed a doublet attributable to paramagnetic high-spin Fe 3+ , which presumably originates from goethite (α-FeOOH) exhibiting superparamagnetic relaxation due to its small particle size. The blue fragments contained little iron. The scattered X-ray Moessbauer spectra revealed that the thickness of the pigments was larger than 20 μm.

  16. Moessbauer effect study on the corrosion of an oil refinery

    International Nuclear Information System (INIS)

    Da Costa, M.I. Jr.; Kunrath, J.I.; Moro, J.T.; Englert, G.; Comparsi, L.U.; Mueller, I.L.

    1994-01-01

    Metallic coupons are placed in strategical points of an oil refining plant in order to control the amount of corrosion produced by amine stripping of H 2 S from liquefied oil and combustible gases. This paper reports some of the results obtained by CEMS and transmission Moessbauer spectroscopy for the corrosion products formed on such coupons. (orig.)

  17. A Moessbauer study of deep sea sediments

    International Nuclear Information System (INIS)

    Minai, Y.; Tominaga, T.; Furuta, T.; Kobayashi, K.

    1981-01-01

    In order to determine the chemical states of iron in deep sea sediments, Moessbauer spectra of the sediments collected from various areas of the Pacific have been measured. The Moessbauer spectra were composed of paramagnetic ferric, high-spin ferrous, and magnetic components. The correlation of their relative abundance to the sampling location and the kind of sediments may afford clues to infer the origin of each iron-bearing phase. (author)

  18. Moessbauer study of iron-sugar complexes

    International Nuclear Information System (INIS)

    Tonkovic, M.; Music, S.; Hadzija, O.; Nagy-Czako, I.; Vertes, A.

    1982-01-01

    Ferric-fructose complex has been prepared using FeCl 3 and Fe(NO 3 ) 3 solutions. Molecular weight determination and Moessbauer spectroscopic measurements proved that the ferric-fructose complex is polymeric in solid state and also in aqueous solution. The synthesis of a new iron-sorbose complex has been performed. Its Moessbauer spectra indicate a structure similar to that of the iron-fructose complex. (author)

  19. High field Moessbauer spectroscopy using water-cooled magnets

    Energy Technology Data Exchange (ETDEWEB)

    Chappert, J.; Regnard, J. R.

    1974-07-01

    A high field Moessbauer spectrometer using a Bitter coil producing fields of up to 155 kOe is described. Problems encountered in the design of this type of equipment are discussed and preliminary results demonstrating the performance of the spectrometer are presented.

  20. Rapid spin-state interconversion in the bis-complex of tris-(1-pyrazolyl) methane with Fe(II) studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Winkler, H.; Trautwein, A.X.; Toftlund, H.

    1992-01-01

    Dynamic spin equilibrium is observed in a complex of the [Fe(II)-N 6 ] type above room temperature. The Moessbauer lineshapes as function of temperature can be understood by means of the random-frequency-modulation model. Taking into accout the different Lamb-Moessbauer factors of the low- and high-spin state yields true populations of the two spin states. The transition rates follow rather well an Arrhenius law. With appropriate assumptions an activation energy ΔE LH =18(1) kJmol -1 is deduced. (orig.)

  1. Application of 119Sn Moessbauer spectroscopy to investigations of RET2-X2-type phases

    International Nuclear Information System (INIS)

    Goerlich, E.

    1991-01-01

    Moessbauer spectroscopy of 119 Sn is an effective tool to study nuclear hyperfine interactions which in turn are important as a source of information complementary to that supplied by ''classical'' methods. However, particularly when the effects are subtle, experimental conditions as well as data analysis should be handled with care. The attention is devoted primarily to the finite absorber thickness effects. As examples serve our recent results obtained from investigations of ternary tetragonal phases of RET 2 X 2 -type. In EuPd 2 Si 2 mixed valent system 119 Sn was used as probe which detects the influence of Eu-valency change at a distant site of Si. Electrical resistivity measurements in CeNi 2 Sn 2 may indicate a Kondo-type behaviour while Moessbauer effect leads to the conclusion in favour of a magnetically ordered state. The analysis of resonance absorption spectra of CeAg 2 Sn 2 using a full transmission integral indicates the presence of a metallic β-tin in the sample, while data fitting within the thin absorber approximation has lead to the opposite conclusion. Neither in CeNi 2 Sn 2 nor in ErNi 2 Sn 2 the temperature dependence of the recoil free factors alone cannot explain the observed broadening of spectra at low temperatures. (author). 14 refs, 13 figs

  2. The big and little of fifty years of Moessbauer spectroscopy at Argonne

    International Nuclear Information System (INIS)

    Westfall, C.

    2005-01-01

    Using radioactive materials obtained by chance, a turntable employing gears from Heidelberg's mechanical toy shops, and other minimal equipment available in post World War II Germany, in 1959 Rudolf Moessbauer confirmed his suspicion that his graduate research had yielded ground-breaking results. He published his conclusion: an atomic nucleus in a crystal undergoes negligible recoil when it emits a low energy gamma ray and provides the entire energy to the gamma ray. In the beginning Moessbauer's news might have been dismissed. As Argonne nuclear physicist Gilbert Perlow noted: ''Everybody knew that nuclei were supposed to recoil when emitting gamma rays--people made those measurements every day''. If any such effect existed, why had no one noticed it before? The notion that some nuclei would not recoil was ''completely crazy'', in the words of the eminent University of Illinois condensed matter physicist Frederich Seitz. Intrigued, however, nuclear physicists as well as condensed matter (or solid state) physicists in various locations--but particularly at the Atomic Energy Research Establishment at Harwell in Britain and at Argonne and Los Alamos in the U.S.--found themselves pondering the Moessbauer spectra with its nuclear and solid state properties starting in late 1959. After an exciting year during which Moessbauer's ideas were confirmed and extended, the physics community concluded that Moessbauer was right. Moessbauer won the Nobel Prize for his work in 1961. In the 1960s and 1970s Argonne physicists produced an increasingly clear picture of the properties of matter using the spectroscopy ushered in by Moessbauer. The scale of this traditional Moessbauer spectroscopy, which required a radioactive source and other simple equipment, began quite modestly by Argonne standards. For example Argonne hosted traditional Moessbauer spectroscopy research using mostly existing equipment in the early days and equipment that cost $100,000 by the 1970s alongside work at

  3. The big and little of fifty years of Moessbauer spectroscopy at Argonne.

    Energy Technology Data Exchange (ETDEWEB)

    Westfall, C.

    2005-09-20

    Using radioactive materials obtained by chance, a turntable employing gears from Heidelberg's mechanical toy shops, and other minimal equipment available in post World War II Germany, in 1959 Rudolf Moessbauer confirmed his suspicion that his graduate research had yielded ground-breaking results. He published his conclusion: an atomic nucleus in a crystal undergoes negligible recoil when it emits a low energy gamma ray and provides the entire energy to the gamma ray. In the beginning Moessbauer's news might have been dismissed. As Argonne nuclear physicist Gilbert Perlow noted: ''Everybody knew that nuclei were supposed to recoil when emitting gamma rays--people made those measurements every day''. If any such effect existed, why had no one noticed it before? The notion that some nuclei would not recoil was ''completely crazy'', in the words of the eminent University of Illinois condensed matter physicist Frederich Seitz. Intrigued, however, nuclear physicists as well as condensed matter (or solid state) physicists in various locations--but particularly at the Atomic Energy Research Establishment at Harwell in Britain and at Argonne and Los Alamos in the U.S.--found themselves pondering the Moessbauer spectra with its nuclear and solid state properties starting in late 1959. After an exciting year during which Moessbauer's ideas were confirmed and extended, the physics community concluded that Moessbauer was right. Moessbauer won the Nobel Prize for his work in 1961. In the 1960s and 1970s Argonne physicists produced an increasingly clear picture of the properties of matter using the spectroscopy ushered in by Moessbauer. The scale of this traditional Moessbauer spectroscopy, which required a radioactive source and other simple equipment, began quite modestly by Argonne standards. For example Argonne hosted traditional Moessbauer spectroscopy research using mostly existing equipment in the early days and

  4. Moessbauer studies of hemoglobin in erythrocytes exposed to neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Niemiec, Katarzyna; Kaczmarska, Magdalena; Buczkowski, Mateusz [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland); Fornal, Maria [Collegium Medicum, Jagiellonian University, Department of Internal Medicine and Gerontology (Poland); Pohorecki, Wladyslaw [AGH University, Faculty of Energy and Fuels (Poland); Matlak, Krzysztof; Korecki, Jozef [AGH University, Faculty of Physics and Computer Science, Department of Solid State Physics (Poland); Grodzicki, Tomasz [Collegium Medicum, Jagiellonian University, Department of Internal Medicine and Gerontology (Poland); Burda, Kvetoslava, E-mail: kvetoslava.burda@fis.agh.edu.pl [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland)

    2012-03-15

    We studied radiation effects on the stability of various states of hemoglobin (Hb) in red blood cells (RBC) irradiated with a very low dose of neutron rays, 50 {mu}Gy. We investigated RBCs isolated from blood of healthy donors. Moessbauer spectroscopy was applied to monitor different forms of Hb. Our results show, for the first time, that oxyhemoglobin (OxyHb) and deoxyhemoglobin (DeoxyHb) are two Hb forms sensitive to such a low neutron radiation. Both Hbs change into a new Hb form (Hb{sub irr}). Additionally, OxyHb transfers into HbOH/H{sub 2}O, which under our experimental conditions is resistant to the action of neutron rays.

  5. Research field development ou iron-sulfur proteins by the Moessbauer spectroscopy and EPR

    International Nuclear Information System (INIS)

    Arsenio, T.P.; Taft, C.A.

    1984-01-01

    A research line on iron sulfides (chemical and structurally seemed with the iron-sulfur proteins), implanted and developed at CBPF-Brazil, using the same theoretical and experimental models used in the development of the research field on iron-sulfur proteins is reported. The techniques used are Moessbauer spectroscopy and EPR. (L.C.) [pt

  6. Correlations between the orientation of magnetic recording media determined by Moessbauer spectroscopy and magnetic methods

    International Nuclear Information System (INIS)

    Pott, R.A.; Koch, W.; Leitner, L.

    1986-01-01

    The orientation of the easy magnetization axis of magnetic particles is a key parameter of the recording performance of magnetic recording media. Usually the orientation is measured by magnetic methods, but the applicability of the Moessbauer Spectroscopy has also been shown in the past. The authors show and discuss the correlations between the results obtained by magnetic and Moessbauer measurements for the example of several magnetic tapes. They demonstrate that by a combination of both methods one is even able to estimate the mean canting angles distribution width of the easy axis of magnetization. (Auth.)

  7. Magneto-structural coupling and harmonic lattice dynamics in CaFe2As2 probed by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Li Zhiwei; Ma Xiaoming; Pang Hua; Li Fashen

    2011-01-01

    In this paper we present a detailed Moessbauer spectroscopy study of the structural and magnetic properties of the undoped parent compound CaFe 2 As 2 single crystal. By fitting the temperature dependence of the hyperfine magnetic field we show that the magneto-structural phase transition is clearly first order in nature and we also deduce the compressibility of our sample to be 1.67 x 10 -2 GPa -1 . Within Landau's theory of phase transition, we further argue that the observed phase transition may stem from the strong magneto-structural coupling effect. The temperature dependence of the Lamb-Moessbauer factor shows that the paramagnetic phase and the antiferromagnetic phase exhibit similar lattice dynamics in high-frequency modes with very close Debye temperatures, Θ D ∼ 270 K.

  8. Study on Stereochemical Activity of Lone Pair Electrons in Sulfur and Halogen Coordinated Antimony(III) Complexes by 121Sb Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Ohyama, Ryuhichi; Takahashi, Masashi; Takeda, Masuo

    2005-01-01

    We have measured 121 Sb Moessbauer spectra at 20 K for 52 compounds of antimony(III). An Sb(III) atom with the electron configuration [Kr] 4d 10 5s 2 has a lone pair electrons. The stereochemical property of the lone pair has been found to depend very much on the kinds of atoms surrounding the antimony atom and the configurations of the coordinating atoms.

  9. Metallurgical applications of the Moessbauer effect

    International Nuclear Information System (INIS)

    Flinn, P.A.

    1975-01-01

    Recent developments and practical applications of the Moessbauer effect are reviewed. Moessbauer studies into solid solutions, phase transformations in certain alloy systems and steels, deformation-induced transformations in and corrosion of steels are discussed. Also discussed are the applications of Moessbauer spectroscopy in process metallurgy for diffusion measurements in solids and in an accurate quantitative analysis. The use of backscatter geometry is dealt with. (Z.S.)

  10. Magnetic and Moessbauer Studies of Quaternary Argentine Loessic Soils and Paleosols

    International Nuclear Information System (INIS)

    Mercader, R. C.; Sives, F. R.; Imbellone, P. A.; Vandenberghe, R. E.

    2005-01-01

    This paper is a review of the current status about the remaining problems that are found in the investigation of the Quaternary Argentine soils and loessic sediments, and the way that Moessbauer studies can assist in solving them. There are two main types of investigations that make use of the magnetic response of the samples to correlate them with information gathered by other methods. On the one hand, there is the stratigraphic and chronological research, which is of importance from the geological and paleontological points of view. On the other hand, the paleoclimatic records, of significance toward a possible model of the past climate, are also studied because of their close relation to the sediments history. However, there is not yet a model that can tell the difference between the modifications due to the climatic conditions at the time when the soils were buried from processes that occurred after burial. Some examples are given that show that Moessbauer studies can be applied with a certain degree of success when cross-checked with magnetic measurements toward understanding the processes that occurred in alluvial B (paleosols) and C horizons (loess) from the eastern part of Buenos Aires Province. Although the application of Moessbauer studies to hydromorphic processes in soils is not straightforward, there are cases in which Moessbauer spectroscopy, if applied properly and correlated with other techniques, is able to characterize the type of iron oxides existing in the materials and thus assist theories about its origin and history.

  11. Magnetic and Moessbauer Studies of Quaternary Argentine Loessic Soils and Paleosols

    Energy Technology Data Exchange (ETDEWEB)

    Mercader, R. C., E-mail: mercader@fisica.unlp.edu.ar; Sives, F. R. [Universidad Nacional de La Plata, Departamento de Fisica, IFLP, Facultad de Ciencias Exactas (Argentina); Imbellone, P. A. [Universidad Nacional de La Plata, Instituto de Geomorfologia y Suelos (Argentina); Vandenberghe, R. E. [Ghent University, NUMAT, Department of Subatomic and Radiation Physics (Belgium)

    2005-02-15

    This paper is a review of the current status about the remaining problems that are found in the investigation of the Quaternary Argentine soils and loessic sediments, and the way that Moessbauer studies can assist in solving them. There are two main types of investigations that make use of the magnetic response of the samples to correlate them with information gathered by other methods. On the one hand, there is the stratigraphic and chronological research, which is of importance from the geological and paleontological points of view. On the other hand, the paleoclimatic records, of significance toward a possible model of the past climate, are also studied because of their close relation to the sediments history. However, there is not yet a model that can tell the difference between the modifications due to the climatic conditions at the time when the soils were buried from processes that occurred after burial. Some examples are given that show that Moessbauer studies can be applied with a certain degree of success when cross-checked with magnetic measurements toward understanding the processes that occurred in alluvial B (paleosols) and C horizons (loess) from the eastern part of Buenos Aires Province. Although the application of Moessbauer studies to hydromorphic processes in soils is not straightforward, there are cases in which Moessbauer spectroscopy, if applied properly and correlated with other techniques, is able to characterize the type of iron oxides existing in the materials and thus assist theories about its origin and history.

  12. TlCu1.73Fe0.27Se2 studied by means of Moessbauer spectroscopy and SQUID magnetometry

    International Nuclear Information System (INIS)

    Kamali-M, S; Ericsson, T; Haeggstroem, L; Berger, R; Ronneteg, S; Felton, S

    2006-01-01

    TlCu 2-x Fe x Se 2 is a p-type metal for x c is 55(5) K as found from both SQUID and Moessbauer spectra. At T c the magnetic hyperfine fields are distributed with a maximum at about 30 T, which are compared to the measured magnetic moment per iron atom, which is 0.97 μ B /Fe as found from SQUID measurements. The experimental results are compared to results using other methods on isostructural Tl selenides

  13. The Moessbauer spectroscopy in the characterization of atmospheric corrosion products; La espectroscopia Moessbauer en la caracterizacion de productos de corrosion atmosferica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Torres, D; Leiva Ronda, P [Centro de Estudios Aplicados al Desarrollo Nuclear (CEADEN), La Habana (Cuba); Gomez, J; Ronda, M [Centro de Investigaciones del Petroleo, La Habana (Cuba)

    1996-07-01

    A study of corrosion products on mild steel formed after 1 and 5 years exposure in two industrial coastal weathering stations in the Bay from Matanzas City, Cuba, has been carried out. Structural analysis was conducted using mainly transmission Moessbauer Spectroscopy and the X-ray diffraction as complementary technique. The main phases found in the specimen exposed to high chloride containing environment were: lepidocrocite ({gamma}- FeOOH), goethite ({alpha}- FeOOH) and magnetite concentration was the lowest, the phases found were {gamma}- FeOOH and {alpha}- FeOOH, and the phase transformation proposed was {gamma}- FeOOh -> {alpha}- Fe-OOH. In this station were found also amorphous corrosion products. There amorphous phases could be responsible for the lowest levels of corrosion on steel in this station.

  14. Investigation of iron-containing complexes of deoxyribonucleic acid nucleosides by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Greguskova, M.; Novotny, J.; Cernohorsky, I.; Cirak, J.

    1975-01-01

    DNA and nucleoside complexes with ferric and ferrous ions were investigated for the concentration of iron ions, ionic strength, temperature, and the nature and spatial configuration of neighbouring atoms of the iron ions in the complexes. Moessbauer spectroscopy was used. The Moessbauer measurements were conducted on lyophilized samples at room temperature (300 K) and on frozen solutions at liquid nitrogen temperature (77 K). Quadrupole splitting was found in all spectra obtained by a Pd(Co) source, with the exception of thymidine, thus indicating that the formation of complexes had not affected the oxidation state of iron ions. A decrease in isomer shift and an increase in quadrupole splitting were found in all spectra obtained by an iron(III) chloride source as well as in all spectra obtained by an iron chloride tetrahydrate source. UV irradiation of the samples prior to the Moessbauer measurements was found to have no effect on the Moessbauer spectra but to result in changes in the oxidation state of iron ions, mainly their valency and the ferrous/ferric ion ratio. The results are shown in a table and in graphs. (L.O.)

  15. Some antarctic lacustrine sediments from northern Victoria Land investigation by Moessbauer spectroscopy, INNA and XRD

    International Nuclear Information System (INIS)

    Stievano, L.; Bertelle, M.; Leotta, G.; Calogero, S.; Constantinescu, S.; Oddone, M.

    1999-01-01

    Fifteen lacustrine sediments, sampled during the 1994-1995 Austral summer in Northern Victoria Land (Antarctica), were characterised by 57 Fe Moessbauer spectroscopy, instrumental neutron activation analysis and X-ray diffraction. These sediments are related to the intrusive rocks from Granite Harbour, to the metamorphic rocks of the Complex of Wilson Terrane and the volcanic rocks from Mc Murdo. The samples contain quartz, alkaline feldspars, plagioclases, amphiboles, biotite, chlorite and muscovite except for the sediments of volcanic origin that contain alkaline feldspars, plagioclases and pyroxenes. The paramagnetic components of the Moessbauer spectra were assigned mainly to the iron sides in biotites except for those displayed from the sediments of volcanic origin assigned mainly to pyroxenes. Moessbauer spectra at room temperature do not display magnetic ordering except for those of the sediments of volcanic origin containing bulk magnetite, hematite and goethite. Moessbauer spectra collected at the liquid helium temperature always exhibit magnetic ordering. This spectral difference has been attributed to the different dimensions of the iron oxide particles in the sediments. The scarce weathering involves a partial transformation of magnetite in hematite and goethite in the sediment of volcanic origin. In the remaining sediments a partial hydrolysis of biotite together with a partial oxidation of iron (II) retained in silicates is present. (authors)

  16. Oxidation study by Moessbauer and optic microscopy of steels from boiler tubes used in sugar industry

    International Nuclear Information System (INIS)

    Fajardo, M.; Perez Alcazar, G.A.; Aguilar, Y.

    1998-01-01

    Optic microscopy and Moessbauer spectroscopy were used to study the fail and the inner rusted surface of two boiler tubes used in the sugar industry, respectively. The studied tubes, of the type ASTM A 192, were found to have cracks. By optic microscopy it was observed that the failure begins in the inner surface with circumferential cracking. Also, inside and around the surface close to the cracks a rusted layer was detected. Powder from these layers was collected for Moessbauer spectroscopy analysis. By this method the presence of two or three types of Fe oxides such as wuestite, magnetite and hematite, was proved. These results permit to conclude that the failure mechanism was the thermal fatigue due to a hot work in an O 2 -rich vapor atmosphere. The rusted products are stable at high temperatures

  17. Preparation of thin targets from powders for Moessbauer spectroscopy; Izrada tankih meta od praskastih materijala za Mossbauer-ovu spektroskopiju

    Energy Technology Data Exchange (ETDEWEB)

    Jurela, Z; Jokic, T; Goncic, B [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)

    1979-07-01

    To study radiation damage in the specimen bombarded by the beams of fast particles the Moessbauer spectroscopy can be used. This is one of nondestructive methods for studying radiation damage. The use of this method of investigation and sputtering processes as well as for the study of the phenomena associated with these processes. These studies enable the complete image of the above processes. In this work we shall discuss the preparation of thin targets made from powder material. the method is based mainly on the use of various compounds of iron. Under the influence of the bombardment by fast ions the transformations of the iron compounds occur. (author)

  18. Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

    International Nuclear Information System (INIS)

    Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

    1993-01-01

    The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

  19. Moessbauer study of tetramethylene bridged ferrocene derivatives Pt. 2

    International Nuclear Information System (INIS)

    Nagy, A.G.; Hillman, M.

    1978-01-01

    Suppositions for the molecular structure of trimethylene bridged ferrocene derivatives, i.e. for the tilt of cyclopentadienyl-rings and shortening of iron-ring distance, were supported by Moessbauer spectroscopic studies. The Moessbauer spectra of 1,1'-tetramethyleneferrocene and 1,1',3,3'-bis(tetramethylene)ferrocene were recorded by means of a constant acceleration type spectrometer using a 57 Co source in a chromium matrix. Simultaneous X-ray analysis of 1,1',3,3'-bis(trimethylene)ferrocene and 1,1',2,2',4,4'-tris(trimethylene)ferrocene confirmed the suppositions. (D.P.)

  20. Study of clays by means of Moessbauer spectoscopy

    International Nuclear Information System (INIS)

    Marticorena, B.

    1982-01-01

    A Moessbauer spectroscopic method has been applied to study layers of clays originating from different places and ceramic from Pachacamac, an archeological site near Lima. We have performed a Moessbauer analysis of the samples mentioned above, submitting them to a thermal treatment in order to determine the influcence on the mineral ferrous compounds of the time and the baking atmoshere. The results obtained do not allow us to conclude that such a method is useful either in the case of clays and/or ceramics which are coming from different places or of archeological

  1. A data-acquisition and processing system for Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Fever, H.Th. le

    1979-01-01

    A state of the art data-aquisition system for four simultaneous and independent Moessbauer experiments has been implemented utilizing a general purpose minicomputer and low cost microprocessors. In this system, the microprocessors are dedicated to real-time data collection from the experiments while the minicomputer is being utilized for controlling the microprocessors and processing the data. Extensive consideration was given in the design of the system to achieve the most advantageous balance between hardware and software, i.e. to maintain the ease of handling and full capability of hardwired systems without employing sophisticated hardware. The concept of the design is independent of the type of processor, and may be applied to other experiments requiring real-time data collection and off-line data processing facilities. (Auth.)

  2. Application of Moessbauer spectroscopy to iron-57 bauxite

    International Nuclear Information System (INIS)

    Hill, V.G.; Wynter, C.

    1978-01-01

    Five different samples from bauxite and related terrains in Jamaica were selected for Moessbauer analysis. Sample 1 is lithiophorite, a lithium aluminum manganese oxide, present as an impurity in Jamaican bauxite; sample 2 is a common red bauxite ore, from Kirkvine, Manchester; sample 3 is a pisolitic bauxite from Reynolds, St. Ann; sample 4 is a red bauxite with pisolites from Mocho; and sample 5 is a shaly material containing some lateritic material which characterizes mining areas. Whereas sample 1 contains fine particles of goettite and/or aluminium substituted goettite, samples 2,3,4,5 contain mixtures of haematite and goettite and/or aluminium substituted goettite in varying concentrations. The findings are consistent with Hill's bauxitization process

  3. Theoretical study of Moessbauer hyperfine parameters of Fe bound to ammonia

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1995-01-01

    The first-principles Discrete Variational method was employed to study the species formed by the interaction of an Fe atom and ammonia. Total energy calculations were performed for several configurations. The hyperfine parameters isomer shift, quadrupole splitting and magnetic hyperfine were calculated for the ground state found, and compared to reported experimental values obtained by Moessbauer spectroscopy in frozen ammonia. (author). 14 refs, 1 tab

  4. Moessbauer Study of a Celtic Pottery-Making Kiln in Lower Bavaria

    International Nuclear Information System (INIS)

    Gebhard, R.; Guggenbichler, E.; Haeusler, W.; Riederer, J.; Schmotz, K.; Wagner, F. E.; Wagner, U.

    2004-01-01

    In 1995 a well preserved 3rd century BC Celtic kiln for pottery making was excavated at Schmiedorf in Lower Bavaria. The firing chamber and the flue plate of the kiln were preserved, whereas the dome was not found. We report on a study of material from this kiln by neutron activation analysis, thin-section microscopy, X-ray diffraction and Moessbauer spectroscopy, all performed with the aim to learn more about pottery-making procedures in Celtic times.

  5. Moessbauer study of Haltern 70 amphora sherds from Castro do Vieito, North of Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Costa, B F O; Ramos Silva, M [CEMDRX, Department of Physics, University of Coimbra, P-3004-516, Coimbra (Portugal); Pereira, G [Science Museum of the University of Coimbra, P-3000-272, Coimbra Portugal (Portugal); Silva, A J M [Centro de Estudos Arqueologicos das Universidades de Coimbra e do Porto/CAM, Palacio de Sub-Ripas P-3004-395 Coimbra (Portugal); Carmo, S J C do, E-mail: benilde@ci.uc.p [GIAN, Department of Physics, University of Coimbra, P-3004-516, Coimbra (Portugal)

    2010-03-01

    Haltern 70 amphora sherds obtained from Castro do Vieito were studied by Moessbauer spectroscopy, X-ray diffraction and X-ray fluorescence. In all our samples non magnetic Fe{sup 3+} haematite species were found. In some samples, also Fe{sup 2+} was found. We conclude that the samples were fired under changing atmosphere, air being admitted at the end of the firing cycle following firing in a reducing atmosphere.

  6. Moessbauer and positron annihilation studies of structural modifications of hemoglobin in solution

    International Nuclear Information System (INIS)

    Oshtrakh, M.I.; Kopelyan, E.A.; Semionkin, V.A.

    1995-01-01

    Structural modifications of human adult oxyhemoglobin in concentrated solution were studied by Moessbauer and positron life-time spectroscopies. The effects of non-sterile degradation and irradiation by γ-rays were compared by both techniques. It was found that positron annihilation parameters were sensitive to the structural modifications of hemoglobin molecules in solution and could be related with the conformational states of hemoglobin. (author)15 refs.; 3 tabs

  7. Moessbauer spectroscopic studies of the magnetic and structural properties of novel nanophase magnetic materials

    International Nuclear Information System (INIS)

    Milford, G.H.

    2000-08-01

    57 Fe Moessbauer Spectroscopy and complementary techniques have been used to characterise the physical and magnetic properties of a variety of novel nanophase iron containing magnetic particles, over a range of temperatures, and applied magnetic fields. Two series of commercially produced advanced metal particle pigments and tapes intended for use as magnetic recording media have been characterised using Transmission and Conversion Electron Moessbauer Spectroscopy at 4.2K, 77K and 293K. Moessbauer Spectra at 4.2K and 293K have identified two different forms of iron within the samples, an iron alloy core and an Fe 3+ oxide passivation layer. The first series of metal particle pigments studied is split into two separate groups, the core of the first group consists of a disordered Fe/Co alloy. Whereas the second group of metal particle pigments studied within the series have shown different characteristics than the previous samples, as the core is no longer a simple Fe/Co alloy. In addition to this the particle size is significantly reduced in the final sample within the series. This may be due to the presence of an Fe 2+ component, which appears to reduce the amount of Fe 3+ component necessary to passivate the particles by approximately half. The second series of samples have been used in part to investigate the out of plane angle of the metal particle pigments and its relationship with the squareness of the metal particle tapes. It is vital to minimise the out of plane angle of the metal particle tapes to obtain the optimum magnetic properties of the metal particle pigment. It has been shown that a decreasing out of plane angle leads to an increase in the squareness of the tapes. As a consequence of this the switching field distribution can be narrowed on metal particle tapes by reducing the out of plane angle. A further investigation has been carried out on the metal particle pigments coated onto tapes using Conversion Electron Moessbauer Spectroscopy, in order to

  8. Moessbauer thermal scan study of a spin crossover system

    Energy Technology Data Exchange (ETDEWEB)

    Zelis, P Mendoza; Pasquevich, G A; Sanchez, F H; Veiga, A; Cabrera, A F [Departamento de Fisica, FCE-UNLP, La Plata (Argentina); Ceolin, M [Instituto de Investigaciones FIsico-Quimicas Teoricas y Aplicadas (UNLP-CONICET), La Plata (Argentina); Coronado-Miralles, E; Monrabal-Capilla, M; Galan-Mascaros, J R, E-mail: pmendoza@fisica.unlp.edu.a [Instituto de Ciencias Moleculares, Universidad de Valencia, Valencia (Spain)

    2010-03-01

    Programmable Velocity equipment was used to perform a Moessbauer Thermal Scans to allow a quasi-continuous temperature study of the magnetic transition between the low-spin and a high-spin configurations in [Fe(Htrz){sub 2}(trz)](BF4) system. The material was studied both in bulk as in nanoparticles sample forms.

  9. Low temperature Moessbauer study of amorphous Fe83B17

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.

    1987-01-01

    Information about changes in magnetic structures of metallic glass Fe 83 B 17 at low temperatures has been obtained by 57 Fe Moessbauer spectroscopy in the temperature range from 295 to 77 K. The mean values of the magnetic hyperfine field have been calculated from magnetic splitting of Moessbauer spectra. The angle between the direction of magnetization and the γ-ray direction θ obtained from line intensity ratios is given as a function of temperature. The curve shows a minimum at 120 K. The influence of decreasing temperature on the magnetic structure may be caused by a change in magnetic anisotropy and a reorientation of surface spins. The main contribution to the changes in θ comes from the reorientation of surface domains

  10. Moessbauer study of spin alignment in substituted lithium ferrites

    International Nuclear Information System (INIS)

    Abeledo, C.R.; Frankel, R.B.

    1977-01-01

    To explain the decrease of magnetic moment in zinc substituted lithium ferrites Dionne has proposed a model which includes canting of the B sublattice moments as zinc is substituted in the A sublattice. Moessbauer spectroscopy in external magnetic fields is applied to investigate the existence of canting in (Lisub(0.5)Fesub(0.5))sub(1-x)Znsub(x)Fesub(2)Osub(4) with x=0 and x=0.3. The samples used were either polycrystalline powders or circular disks cut from pressed blocks and lapped down to a thickness of 0.1mm. In the x=0 samples the Δm=0 Moessbauer lines vanish for external fields below 10kOe. For x=0.3 the Δm=0 lines vanish at external magnetic fields close to 15kOe. results seem to indicate a small canting angle in the x=0.3 samples

  11. Moessbauer Spectroscopy in the Characterization of waste product used like fertilizer in soil. Some Applications

    International Nuclear Information System (INIS)

    Furet, N. R.; Orihuela, D. L.; Hernandez

    2007-01-01

    At the present time, the use of industrial solid wastes is an important task, because a great effort that have been carried out to preserve the environmental and to obtain the high technologies. In this work, a characterization of a industrial waste product, on base of the monohydrous iron sulphate (FeSO 4 .1H 2 O) with a 15% approximately of free sulphuric acid, used like improvement of soil was carried out by Mossabuer spectroscopy. This waste product was used in a series of the experiences in parcels (where peaches, (Prunus persica), strawberries are cultivated) in the zone of Cartaya (Huelva, Spain). The characterisation of soil from the parcel before application of this product was carried out in order to analyse and compare with the final results by using the methods of the Moessbauer spectroscopy. High contents of Fe, S, and Zn at the studied product are observed . This elements are very important for plants. The pH in soil and Fe, Mn, and Zn contents in soil and leaf were determined. The knowledge of the main chemical-structural properties of this product, used like improvement of soil, will permit the study of the influence to) on the soil properly, b) on the peach leaves and c) on the foodstuff fruit. (Author)

  12. Aging effect in CaLaBa{l_brace}Cu{sub 1 - x}Fe{sub x}{r_brace}{sub 3}O{sub 7 - {delta}} with 0 {<=} x {<=} 0.07 studied by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bustamante, Angel, E-mail: angelbd1@gmail.com [Universidad Nacional Mayor de San Marcos, Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas (Peru); Santos Valladares, Luis De Los, E-mail: ld301@cam.ac.uk [University of Cambridge, Cavendish Laboratory (United Kingdom); Flores, Jesus [Universidad Nacional Mayor de San Marcos, Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas (Peru); Barnes, Crispin H. W. [University of Cambridge, Cavendish Laboratory (United Kingdom); Majima, Yutaka [Tokyo Institute of Technology, Materials and Structures Laboratory (Japan)

    2011-11-15

    In this work, we study the long-term aging effect caused by Fe atoms in the superconductor CaLaBa{l_brace}Cu{sub 1 - x}Fe{sub x}{r_brace}{sub 3}O{sub 7 - {delta}} with 0 {<=} x {<=} 0.07. XRD confirms that this system has a YBCO-like structure. The critical temperature (T{sub c}) is strongly affected by aging and depends on the amount of Fe in the structure. Room temperature Moessbauer spectroscopy reveals the presence of the typical species A, B-B Prime , C and new species E Prime and F. Interestingly; A, which corresponds to the Fe{sup 3 + } atom located in the Cu(1) of the chains with spin S{sub z} = 3/2, shows a drastic reduction which means migration to the species B, B Prime and C. Species B and B Prime correspond to the Fe{sup 3 + } in the Cu(2) site forming planar quasi-octahedral and planar square pyramidal, while the C specie is a square pyramidal with O(5) respectively (spin S{sub z} = 3/2 in all these cases). Aging causes loss of superconductivity in the samples with 5 and 7% of iron content.

  13. 57Fe Moessbauer studies on Ni-Mo system in the critical region

    International Nuclear Information System (INIS)

    Das, D.; Chintalapudi, S.N.; Mukhopadhyay, P.K.; Mookerjee, A.; Mukherjee, G.D.

    2001-01-01

    Disordered magnetic system NiMo is investigated in the critical region (Mo concentration 10 and 11 wt %) using Moessbauer spectroscopy as a local probe. 57 Co activity has been diffused in the alloy and is used at the source while stainless steel is used as standard absorber. Moessbauer spectrum of the alloy showed a sharp singlet at room temperature which indicates that 57 Co atoms have gone to the substitutional site. Below 200 K, Moessbauer spectra indicate complicated hyperfine interactions and more than one magnetic phase in the samples. Moessbauer results are corroborated by ac susceptibility, resistivity and positron annihilation Doppler broadening measurements. (author)

  14. Study of the local induction in the superconductor YBa2Cu3O7-δ by Moessbauer spectroscopy using the probe 170Yb3+: methodology and results

    International Nuclear Information System (INIS)

    Vaast-Paci, Ch.

    1997-01-01

    This thesis is concerned with the measurement of the local induction in the anisotropic type II superconductor YBa 2 Cu 3 O 7-δ in presence of an applied field. In this compound, the field penetrates in the form of vortices whose characteristics are governed by both intrinsic (critical fields, anisotropy, penetration lengths,...) and extrinsic parameters (such as pinning centers). We have developed a new microscopic technique to measure the local fields using Moessbauer probes 170 Yb 3+ dilutes for Y 3+ . The measurements are based on the field dependence (size and direction) of the Moessbauer transitions between the electronuclear levels of the probe. These probes are distributed randomly over the sample so the measurements provide both the size and the direction of the internal field distribution over the whole sample. The possible measurement range extends from below 50 Oe to about 4000 Oe, for temperatures up to 60 deg.K. Measurements were made at T4.2 deg. K, for sintered pellets with different oxygen amount and for optimally doped ci-axis oriented single crystals. The penetration length measurements showed that the density of the superconducting condensate increases progressively with carrier doping. Field penetration measurements furnished the microscopic lower penetration field H cl , and enabled us to propose a model describing the profile of the flux distribution which is controlled by the pinning centers. The measurements also evidenced an anomalous penetration in small sized single crystals. In additions, we obtained the average direction of the vortices when the applied field is titled from the c axis and we showed that the vortex direction depends on the way the field is applied (ZFC or FC configuration) and that there exists a competition between the pinning forces and the intrinsic anisotropy. (author)

  15. Moessbauer study of iron diffusion in beryllium

    International Nuclear Information System (INIS)

    Sepiol, B.; Ruebenbauer, K.; Miczko, B.; Birchall, T.

    1991-01-01

    The broadening of the 14.41 keV Moessbauer line of 57 Fe dure to diffusion of iron atoms in polycrystalline beryllium has been investigated in the temperature range 1123 to 1423 K. The observed broadenings obey the Arrhenius law with activation energy 1.66(10) eV, i.e., lower than that obtained from the corresponding polycrystalline tracer data. The variations of the resonant fraction, second order Doppler shift and quadrupole splitting versus temperature are reported. An average diffusion coefficient has been calculated from the obtained broadenings and compared with the tracer results. (orig.)

  16. Studies on structure and covalence effects on hyperfine interactions of AFeO sub(2) and BFeS sub(2) compounds by Moessbauer spectroscopy (A= Na, Cu, Ag, B= K, Rb, Cs, Na)

    International Nuclear Information System (INIS)

    Taft, C.A.

    1975-01-01

    The compounds AFeO sub(2) and BFeS sub(2) (A = Na, Cu, Ag, B = K, Rb, Cs, Na) were investigated by Moessbauer spectroscopy. The spectra were registered at temperature range from 4.2 sup(0) to 300 sup(0)K and magnetic transitions were observed determining correspondent temperatures by variation of hyperfine field. The electric field gradient of these compounds and perovskite type compounds (Pb sub(1-x) - Ba sub(x)) Zr O sub(3) were calculated and experimental part were determined by perturbed angular correlation, taking in account the effects of covalence, crystal lattice parameters and dipolar contributions. (M.C.K.)

  17. Chebyshev approximations for the transmission integral for one single line in Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Flores-Lamas, H.

    1994-01-01

    An analytic expansion, to arbitrary accuracy, of the transmission integral (TI) for a single Moessbauer line is presented. This serves for calculating the effective thickness (T a ) of an absorber in Moessbauer spectroscopy even for T a >10. The new analytic expansion arises from substituting in the TI expression the exponential function by a Chebyshev polynomials series. A very fast converging series for TI is obtained and used as a test function in a least squares fit to a simulated spectrum. The test yields satisfactory results. The area and height parameters calculated were found to be in good agreement with earlier results. The present analytic method assumes that the source and absorber widths are different. ((orig.))

  18. Application of Moessbauer effect in the study of silicon steels

    International Nuclear Information System (INIS)

    Lonsky, B.; Wiglasz, V.; Prejsa, M.

    1975-11-01

    The results for 1975 are presented of the research task: Application of the Moessbauer effect in the study of silicon steels. Moessbauer spectra were measured on Czechoslovak made materials of Eo 10 quality and of foreign made material of M2H quality in dependence on tensile stress. Moessbauer spectra were measured on identical samples with electrotechnical insulation and after the removal thereof, with the aim of ascertaining the effect of this insulation. All measurements were evaluated on the basis of changes in the intensity ratios of the first and second lines of the spectrum which characterize the domain structure. These measurements have confirmed that electrotechnical insulation forms in the basic material small tensile stresses which improve the magnetic properties of the material. Moessbauer spectra were measured using the absorption method on identical materials in thin foils with the aim of investigating the configuration of Si atoms in the Fe3%Si alloy. It was found that both materials contain Si atoms in both the first and the second coordination spheres. (author)

  19. Moessbauer study of the ageing effects on the structure of CuZnSn shape memory alloy

    International Nuclear Information System (INIS)

    Frackowiak, J.E.; Dutkiewicz, J.; Morgiel, J.

    1986-01-01

    Using the 119 Sn Moessbauer spectroscopy the study of ageing effects on the structure of a CuZnSn shape memory alloy was performed. Two stages of ageing at 200 0 C were observed. The first stage is connected with formation of DO 3 structure and the second stage with precipitation of α and γ phases. (Auth.)

  20. Moessbauer study on the formation process of Fe-K composition in iron-based catalyst for dehydrogenation of ethylbenzene

    International Nuclear Information System (INIS)

    Jiang Keyu; Zhao Zhenjie; Yang Xielong

    2001-01-01

    Fe-K spinel structure is the predecessor of active phase of potassium promoted iron-based catalyst for dehydrogenation of ethylbenzene. Moessbauer spectroscopy has been used to study the formation process of Fe-K spinel structure which depends on the catalyst composition and preparing condition. The results may prove useful for production of industrial catalyst

  1. Moessbauer studies of microscopic disorder in solid electrolytes

    International Nuclear Information System (INIS)

    Pasternak, M.

    1987-01-01

    We implement for the first time Moessbauer spectroscopy (MS) to investigate short-range properties of disorder in solid electrolytes. MS in 129 I and 119 Sn was carried out in RbAg 4 I 5 and as impurity in Ag 2 Se, respectively. Measurements were performed both in the superionic and the normal phases. It is shown that localized cation hopping is an inherent feature of the α-AgI-type solid electrolytes. In RbAg 4 I 5 , at temperatures far below T c , a small fraction of Ag is still locally mobile and at T>T c , its concentration increases exponentially. A strong linear temperature dependence of the point-charge electric field gradient is observed and explained in terms of local hopping. With 119 Sn in Ag 2 Se we observe the onset of 'local melting' of the Ag surroundingt the SnSe 4 cluster at 50 K below the bulk superionic phase transition. The characteristic features of MS related to microscopic studies of solid electrolytes are fully described. (orig.)

  2. Moessbauer Study of Ceramic Finds from the Galeria de las Ofrendas, Chavin de Huantar

    International Nuclear Information System (INIS)

    Lumbreras, L. G.; Gebhard, R.; Haeusler, W.; Kauffmann-Doig, F.; Riederer, J.; Sieben, G.; Wagner, U.

    2003-01-01

    Ceramic finds from the Galeria de las Ofrendas at Chavin de Huantar and surface finds from the settlement of Chavin were characterised by combining the results of archaeological typology with archaeometric studies using neutron activation analysis, Moessbauer spectroscopy, X-ray diffraction and thin-section microscopy. Sherds from the pyramid Tello are included in the study as representative of local material. The analyses show that the vessels were made from different raw materials and that different firing procedures were used in their production. Sherds of certain styles largely exhibit similar types of Moessbauer patterns and in many instances also have similar element compositions. This supports the archaeological notion that the vessels were brought to Chavin from the provinces, perhaps on the occasion of a festivity.

  3. Moessbauer and calorimetric studies of portland cement hydration in the presence of black gram pulse

    International Nuclear Information System (INIS)

    Rai, Sarita; Kurian, Sajith; Dwivedi, V. N.; Das, S. S.; Singh, N. B.; Gajbhiye, N. S.

    2009-01-01

    Effect of different concentrations of naturally occurring admixture in the form of fine powder of black gram pulse (BGP) on the hydration of Portland cement was studied by isothermal calorimetry and 57 Fe Moessbauer spectroscopy. The spectra were recorded for anhydrous cement and the hydration products at room temperature and 77 K. In the presence of BGP, the spectra showed superparamagnetic doublets at room temperature and the sextet at 77 K, due to the presence of fine particles of iron containing component. Moessbauer studies of hydration products confirmed the formation of nanosize hydration products containing Fe 3+ . The isomer shift (δ) and the quadrupole splitting (ΔE Q ) values of C 4 AF in the cement confirmed iron in an octahedral and tetrahedral environment with +3 oxidation state. The high value of quadrupole splitting showed the high asymmetry of the electron environment around the iron atom. The overall mechanism of the hydration of cement in presence of BGP is discussed.

  4. Iron in Alzheimer's and Control Hippocampi - Moessbauer, Atomic Absorption and ELISA Studies

    International Nuclear Information System (INIS)

    Galazka-Friedman, J.; Szlachta, K.; Bauminger, E.R.; Koziorowski, D.; Friedman, A.; Tomasiuk, R.; Jaklewicz, A.; Wszolek, Z.K.; Dickson, D.; Kaplinska, K.

    2011-01-01

    Alzheimer disease is a neurodegenerative process of unknown mechanism taking place in a part of the brain - hippocampus. Oxidative stress and the role of iron in it is one of the suggested mechanisms of cells death. In this study several methods were used to assess iron and iron binding compounds in human hippocampus tissues. Moessbauer spectroscopy was used for identification of the iron binding compound and determination of total iron concentration in 12 control and one Alzheimer disease sample of hippocampus. Moessbauer parameters obtained for all samples suggest that most of the iron is ferritin-like iron. The average concentration of iron determined by Moessbauer spectroscopy in control hippocampus was 45 ± 10 ng/mg wet tissue. The average concentration of iron in 10 Alzheimer disease samples determined by atomic absorption was 66 ± 13 ng/mg wet tissue. The concentration of H and L chains of ferritin in 20 control and 10 AD hippocampi was assessed with enzyme-linked immuno-absorbent assay. The concentration of H and L ferritin was higher in Alzheimer disease compared to control (19.36 ± 1.51 vs. 5.84 ± 0.55 ng/μg protein for H, and 1.39 ± 0.25 vs. 0.55 ± 0.10 for L). This 3-fold increase of the concentration of ferritin is accompanied by a small increase of the total iron concentration. (authors)

  5. Application of Moessbauer spectroscopy for the characterization of iron-containing catalysts

    International Nuclear Information System (INIS)

    Phillips, J.

    1998-01-01

    Work in our laboratory demonstrates the unique analytical power as well as the limits of Moessbauer Spectroscopy (MES) as a tool for characterizing the size and phase of supported iron containing catalyst particles, particularly carbon supported catalysts. The major challenge in employing MES to characterize catalytic particles is understanding the impact of the relaxation effects on the spectra. Proper methods yield particle size and phase information, whereas improper interpretation can lead to the misidentification of phases. This is illustrated by feeding ersatz 'relaxed' spectra data, generated mathematically with a program which accounts for all aspects of relaxation, to a standard fitting routine. The fitting routine misinterprets the data and provides false phase identification. Methods for recognizing relaxation phenomena and strategies for extracting correct information from relaxed spectra are reviewed. Also reviewed are the major findings of studies on carbon supported catalysts. For example, MES studies, in conjunction with other techniques, demonstrate that bulk and surface structures which are easily accessible for carbon supported bimetallics are generally not found on refractory oxides

  6. Moessbauer study of the magnetic filler for suppositories

    International Nuclear Information System (INIS)

    Bykov, A.V.; Nikolaev, V.I.; Shulgin, V.I.; Diaz, C.; Kharitonov, Yu.Ya.; Cherkasova, O.G.

    1991-01-01

    Moessbauer spectroscopy methods are discussed when applied to test the properties of magnetic suppositories used in medicine. The experiments were carried out on magnetic rectal suppositories containing paramadine and fine-dispersed ferrite powder (BaO.nFe 2 O 3 ) as a magnetic filler. According to the data on the value of effective magnetic field on 57 Fe nuclei in ferrite magnetic sublattices, the stoichiometric n-number equals approximately 5.5; this value corresponds to the composition range of optimal magnetic properties. (orig.)

  7. Moessbauer study of the magnetic filler for suppositories

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, A.V.; Nikolaev, V.I.; Shulgin, V.I. (M.V. Lomonosov Moscow State Univ. (USSR)); Diaz, C. (Cuba National Center of Scientific Research, Havana (Cuba)); Kharitonov, Yu.Ya.; Cherkasova, O.G. (I.M. Sechenov First Moscow Medical Inst. (USSR))

    1991-11-01

    Moessbauer spectroscopy methods are discussed when applied to test the properties of magnetic suppositories used in medicine. The experiments were carried out on magnetic rectal suppositories containing paramadine and fine-dispersed ferrite powder (BaO.nFe[sub 2]O[sub 3]) as a magnetic filler. According to the data on the value of effective magnetic field on [sup 57]Fe nuclei in ferrite magnetic sublattices, the stoichiometric n-number equals approximately 5.5; this value corresponds to the composition range of optimal magnetic properties. (orig.).

  8. Moessbauer study of ancient iron smelting slag in Japan

    International Nuclear Information System (INIS)

    Nakanishi, A.

    2008-01-01

    For an investigation of the ancient iron manufacturing technique, a reproducing experiment was carried out by archaeologists, where ancient type of iron smelting furnace was built and iron sand with high titanium contents was used as the raw material. During the operation of furnace, a large amount of slag flowed away from the furnace. In order to investigate the possibility for the estimation about the operative condition of furnace and the raw material, 57 Fe Moessbauer spectroscopy was applied for characterizing these slags and it was found that these slags mainly consisted of ferropseudobrookite (FeTi 2 O 5 ).

  9. Evaluation the homogenisation behaviour of Sm-Fe-Nb materials by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sinan, S. A.; Muryaed, Y.; Alhweg, F. A.

    2004-01-01

    The microstructure of cast and annealed Sm-Fe-Nb materials were investigated by Moessbauer spectroscopy. The aim of the present work is to study the effect of Nb additions upon the microstructure of Sm 2 Fe 17 material and evaluation the homogenisation behaviour of different Sm-Fe-Nb materials. The niobium free cast material consisting of the Sm 2 Fe 17 phase and significant amounts of the free iron (α -Fe). Therefore, the homogenisation process is necessary to eliminate the free iron and produce a single Sm 2 Fe 17 phase material. This process takes long annealing time, up to seven days. The Sm 9 .5 Fe 8 7.5 Nb 3 alloy contains the lowest amount of α-Fe among, the Sm-Fe-Nb materials. Thus the homogenisation step was carried out with treatment time (12 hours) smaller than the reported annealing time of Nb-free material (Sm 2 Fe 17 ). Therefore, the addition of at 3% Nb reduces the manufacturing cost of the Sm 2 Fe 17 and makes this based material for permanent magnets, more industrially desirable, due to elimination the free iron with lowest treatment time. Also it was found that the existence of the paramagnetic NbFe 2 phase becomes higher after the homogenisation process, which can be explained due to the diffusion of Nb from Sm 2 Fe 17 phase to paramagnetic NbFe 2 phase, during the annealing process. (authors)

  10. Moessbauer effect study of the diagenesis on the southern Brazilian Triassic paleoherpetofauna

    International Nuclear Information System (INIS)

    Da Costa, M.I. Jr.; Holz, M.; Schultz, C.L.

    1994-01-01

    Moessbauer spectroscopy is applied to identify the iron contents of bony elements of southern Brazilian Triassic reptile remains, and the question of the paragenetic mineral assemblage is discussed. (orig.)

  11. Conversion electron Moessbauer spectroscopy of plasma immersion ion implanted H13 tool steel

    International Nuclear Information System (INIS)

    Terwagne, G.; Hutchings, R.

    1994-01-01

    Conversion electron Moessbauer spectroscopy (CEMS) has been used to investigate nitride formation in AISI-H13 tool steel after treatment by plasma immersion ion implantation (PI 3 ) at 350 C. With only slight variation in the plasma conditions, it is possible to influence the kinetics of nitride precipitation so as to obtain nitrogen concentrations that range from those associated with ε-Fe 2 N through ε-Fe 3 N to γ'-Fe 4 N. The CEMS results enable a more definite identification of the nitrides than that obtained by glancing-angle X-ray diffraction and nuclear reaction analysis alone. (orig.)

  12. The Moessbauer effect used to study iron minerals in Brazil

    International Nuclear Information System (INIS)

    Kunrath, J.I.

    1975-01-01

    The Moessbauer effect in Fe 57 was used to study iron minerals in Brazil. More than 50 samples were analyzed in this preliminary work. Although many minerals present complex spectra, it was possible to find a number of samples with relatively pure natural materials, which may be considered representative of the simple compounds that enter as constituents in the more complex cases. Important and, in some cases, drastic differences were found between spectra at room and liquid nitrogen temperatures. These differences are reported and in some cases explained. Another feature was the difference in the Moessbauer effect spectra, observable when some crystallization water is present. This phenomenon is correlated to the previous one. The methodology of this study is also reported [pt

  13. Assessment of the optimum degree of Sr{sub 3}Fe{sub 2}MoO{sub 9} electron-doping through oxygen removal: An X-ray powder diffraction and {sup 57}Fe Moessbauer spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Carlos A.; Viola, Maria del C. [Area de Quimica General e Inorganica, Departamento de Quimica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina); Pedregosa, Jose C., E-mail: jpedreg@unsl.edu.ar [Area de Quimica General e Inorganica, Departamento de Quimica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina); Mercader, Roberto C., E-mail: mercader@fisica.unlp.edu.ar [Departamento de Fisica, IFLP-CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata (Argentina)

    2010-10-15

    We describe the preparation and structural characterization by X-ray powder diffraction (XRPD) and Moessbauer spectroscopy of three electron-doped perovskites Sr{sub 3}Fe{sub 2}MoO{sub 9-{delta}} with Fe/Mo = 2 obtained from Sr{sub 3}Fe{sub 2}MoO{sub 9}. The compounds were synthesized by topotactic reduction with H{sub 2}/N{sub 2} (5/95) at 600, 700 and 800 {sup o}C. Above 800 {sup o}C the Fe/Mo ratio changes from Fe/Mo = 2-1 < Fe/Mo < 2. The structural refinements of the XRPD data for the reduced perovskites were carried out by the Rietveld profile analysis method. The crystal structure of these phases is cubic, space group Fm3-bar m, with cationic disorder at the two different B sites that can be populated in variable proportions by the Fe atoms. The Moessbauer spectra allowed determining the evolution of the different species formed after the treatments at different temperatures and confirm that Fe ions in the samples reduced at 600, 700 and 800 {sup o}C are only in the high-spin Fe{sup 3+} electronic state.

  14. Moessbauer studies of impactites from Huamalies province in Huanuco Region

    International Nuclear Information System (INIS)

    Bustamante, A.; Espinoza, S.; Morales, G.; Scorzelli, R. B.

    2005-01-01

    This report is about the X-ray diffraction and Moessbauer studies of three impactite samples denominated PMe-8, PMe-9 and PMe-11 from Huamalies Province in Huanuco Region, Peru. When terrestrial rocks are submitted to pressures higher than 60 GP, the majority is completely melted, forming a kind of glass called impactites. X-ray diffraction indicates the presence of quartz as the principal mineralogical phase in all samples. The 57 Fe Moessbauer spectra at room temperature of samples PMe-8 and PMe-9 show broadened spectra that were fitted using a distribution model. The most probable field of the magnetic component is 34 T, corresponding to the presence of small particles of goethite, confirmed by the 4.2 K spectrum. For the sample PMe-11, the MS showed the presence of well crystallized hematite.

  15. A Moessbauer study of hemoglobin in paroxysmal nocturnal hemoglobinuria

    International Nuclear Information System (INIS)

    Zamorano-Ulloa, R.; Yee-Madeira, H.; Flores-Llamas, H.; Perez-Ramirez, J.G.

    1991-01-01

    The 57 Fe Moessbauer spectra of concentrated hemoglobin (Hb) of normal subjects and six patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) were studied at 300deg K and 77 K. PNH is a very rate autoimmune hematological disease. The possibility of structural alterations of Hb induced by, or as part of the altered PNH-red cell membrane was the objective of this study. The Moessbauer parameters of the Hb of the normal subjects, both at 300 K and at 77 K, are identical to values previously reported. The PNH-Hb spectra show clear differences. They are wider and more asymmetric. At 77 K, an extra doublet grows in with an isomer shift of 0.425 mm/sec. and a quadrupolar splitting of 1.951 mm/sec. The other two doublets have δ's and ΔQ's slightly, but significantly, different from the corresponding values for normal Hb. These results are rationalized in terms of a population of Hb molecules with structures varying very slightly in a narrow range. The spread in structures manifests itself in a wider and more asymmetric Moessbauer spectrum. (orig.)

  16. Study of the EPR and Moessbauer spectra of iron phosphites

    International Nuclear Information System (INIS)

    Ebert, M.; Kavan, L.

    1978-01-01

    The EPR and Moessbauer spectra of polycrystalline samples of ferrous phosphites FeHPO 3 .3H 2 O, FeH 2 P 2 O 5 , FeH 4 P 2 O 6 .1/2H 2 O, FeH 10 P 4 O 12 .4H 2 O and ferric phosphites Fe 2 (HPO 3 ) 3 .9h 2 O, FeH 3 P 2 O 6 .3H 2 O and Fe 4 H 33 P 15 O 45 .6H 2 O were studied. The hydrogen bonds present in hydrogen phosphite anions (polyorthophosphites) produce a decrease in the electron density on the oxygen atom in the anion and thus also a decrease in the crystal field strength with an increasing P/Fe ratio. These changes are reflected not only in the Dq values but also in the g-factors, Moessbauer isomeric shifts and quadropole splitting values. The Moessbauer spectra were measured at laboratory temperature with a Co-57/Pd source (the time for measuring one sample was about 24 hrs) and evaluated on a Hewlett-Packard computer. The EPR spectra of the polycristalline samples were measured at laboratory temperature in the 3 cm region. (T.I.)

  17. Moessbauer spectroscopic studies of hemoglobin and its isolated subunits

    International Nuclear Information System (INIS)

    Hoy, G.R.; Cook, D.C.; Berger, R.L.; Friedman, F.K.

    1986-01-01

    Samples of 90% enriched 57Fe hemoglobin and its isolated subunits have been prepared. Moessbauer spectroscopic measurements have been made on three such samples. Sample one contained contributions of oxyhemoglobin, deoxyhemoglobin, and carbonmonoxyhemoglobin. This sample was studied from a temperature of 90 K down to 230 mK. Measurements were also made at 4.2 K using a small applied magnetic field of 1.0 T. In general, the measured quadrupole splittings and isomer shifts for each component agreed with previous measurements on single component samples in the literature, and thus demonstrated that chemically enriched hemoglobin has not been altered. The second and third samples were isolated alpha and beta subunits, respectively. We have found measurable Moessbauer spectral differences between the HbO 2 sites in the alpha subunit sample and the beta subunit sample. The measured Moessbauer spectral areas indicate that the iron ion has the largest mean-square displacement at the deoxy Hb sites as compared to that at the oxy- and carbonmonoxy Hb sites. The mean-square displacement at the HbO 2 sites is the smallest

  18. Very high pressure Moessbauer spectroscopy using diamond anvil cells

    International Nuclear Information System (INIS)

    Pasternak, M.P.; Taylor, R.D.

    1988-01-01

    The technique of generating very high pressure by means of Diamond Anvil Cells (DAC) for Mossbauer Effect applications is outlined. A comprehensive description is presented of the principles of DAC, modification for the use in M/umlt o/ssbauer Spectroscopy (MS), the Merrill--Bassett and Bassett cells, of pressure measurements, of gasketing and collimation, and of hydrostatic media. Examples of 151 Eu, 119 Sn and 129 I are given showing the feasibility of DAC applications in MS. Other isotopes with potential use for high pressure MS using DAC are suggested. 27 refs., 9 figs

  19. Moessbauer Study of Sedimentary Rocks from King George Island, Antarctica

    International Nuclear Information System (INIS)

    Kuzmann, E.; Souza, P. A. de; Schuch, L. A.; Oliveira, A. C. de; Garg, R.; Garg, V. K.

    2002-01-01

    The separation of continents at the periphery of Antarctica occurred about 180 ma ago due to volcanic activity. Geological faults can be very important in the study of geological occurrences. Such geological faults occur across the Admiralty Bay, King George Island, and have been studied in detail previously. Controversial statements were given in earlier works, based on conventional geological investigations, as to whether altered 'Jurassic' and unaltered Tertiary rocks were separated by a major fault which goes across the Admiralty Bay, or whether there is no difference in the alteration of the rocks located at either side of the fault. The aim of our work is to investigate rock samples from the Admiralty Bay of King George Island, Antarctica, from different locations on both sides of the geological fault. For these investigations 57 Fe Moessbauer spectroscopy and X-ray diffractometry were used. We have found that the phase composition, and the iron distribution among the crystallographic sites of iron-bearing minerals, are characteristic of the location of the rock samples from the Admiralty Bay of King George Island. There is a much higher amount of iron oxides in the rocks from the south part of the geological fault than in the north part. The differences in the mineral composition and iron distribution showed that the rocks in the southern part of the geological fault of King George Island are significantly altered compared to the rocks in the northern part. Our present results support and complement well the results obtained earlier on soils from King George Island.

  20. Moessbauer studies of superexchange interactions in NiFe sub 2 O sub 4

    CERN Document Server

    Kim, S J; Kim, C S; Lee, S W

    2000-01-01

    NiFe sub 2 O sub 4 has been studied using Moessbauer spectroscopy and X-ray diffraction. The crystal was found to have a inverse cubic spinel structure with the lattice constant a sub 0 =8.326+-0.003 A. Moessbauer spectra of NiFe sub 2 O sub 4 was obtained at various absorber temperatures from 13 K to the Neel temperature. The Moessbauer spectra consisted of two sets of six lines corresponding to Fe sup + sup 3 at the tetrahedral (A) and the octahedral (B) sites. The temperature dependence of the magnetic hyperfine fields at sup 5 sup 7 Fe nuclei at the tetrahedral (A) and the octahedral (B) sites was analyzed by the Neel theory of ferrimagnetism. The intersublattice A-O-B and intrasublattice A-O-A superexchange interactions were found to be antiferromagnetic with strengths of J sub A sub - sub B =-25.0 k sub B and J sub A sub - sub A =-4.0 K sub B , respectively, while the intrasublattice B-O-B superexchange interaction is ferromagnetic with a strength J sub B sub - sub B =4.2 k sub B.

  1. Paramagnetic hyperfine interactions of iron in solid ammonia from Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Litterst, F.J.; Saitovitch, E.M.B.; Terra, J.

    1988-01-01

    Moessbauer studies on highly dilute 57 Fe in solid ammonia are reported. The hyperfine parameters of the paramagnetic reaction product FeNH 3 point to a nearly atomic configuration of iron [Ar]3d 7 4s. The electronic spin relaxation slows down rapidly under application of an external magnetic field. The field dependence of the magnetic hyperfine patterns indicates a strong axial magnetic anisotropy. (author) [pt

  2. Characterization of the Roraima savanna across of X-ray diffraction, thermomagnetic analysis and Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gilmar A.; Araujo, R.C.; Sergio, C.S. [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil)

    2012-07-01

    Full text: The technique of X-ray diffraction has great resolving power to determine the phases present in crystalline material, thereby enabling it to determine the elements present in the materials as well as changes in structure that they can suffer when subjected to various physical processes and/or chemical means. The research had as objective to characterize the mineralogy of iron oxides, silicon, aluminum and other minerals in the soil of five points of the Roraima savannah. The points where samples were collected are five municipalities in the state of Roraima. The area of sampling is part of the savanna in Roraima. The samples were collected. We analyzed samples from five points from the collection of natural soil in the locations listed. The samples were placed in a mill to a uniform grain size. After the milling process, the magnetic material was separated using a permanent magnet. Then the samples were analyzed by x-ray diffraction, thermomagnetic analysis and Moessbauer spectroscopy. Preliminary results of XRD showed the occurrence of phases of oxides of iron, silicon, aluminum and other phases less. Thermomagnetic analysis show that the magnetic phases are magnetite and hematite. The results of the Moessbauer spectroscopy indicates the reliability in the two prior art and confirmed the presence of the phases of oxides of iron present in the soil analyzed. (author)

  3. Moessbauer spectroscopy of the Zr-rich region in Zr-Nb-Fe alloys with low Nb content

    International Nuclear Information System (INIS)

    Ramos, C.; Saragovi, C.; Granovsky, M.; Arias, D.

    1999-01-01

    Intermetallic phases and solid solutions in the Zr-rich region of the Zr-Nb-Fe system with low Nb content are studied by Moessbauer spectroscopy complemented with X-ray diffraction, optical and scanning electron microscopy and electron microprobe analysis. The phases found in each sample were those expected from the corresponding binary Zr-Fe system. Furthermore, one of the samples showed a ternary cubic Ti 2 Ni type phase with a similar stoichiometry to the tetragonal Zr 2 Fe compound. Moessbauer parameters were suggested to this phase (IS: - 0.12 mm/s, QS: 0.30 mm/s), to the bcc Zr(β) phase (IS: (-0.11 α 0.01) mm/s, QS: (0.23 α 0.02) mm/s), and to the hcp Zr(β T ) phase (IS: (-0.24 α 0.02) mm/s, QS: (0.45 α 0.02) mm/s)

  4. Moessbauer spectroscopy of the Zr-rich region in Zr-Nb-Fe alloys with low Nb content

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C. [Universidad de Buenos, Facultad de Ciencias Exactas y Naturales (Argentina); Saragovi, C. [Departamento de Fisica, Comision Nacional de Energia Atomica (Argentina); Granovsky, M.; Arias, D. [Departamento de Materiales, Comision Nacional de Energia Atomica (Argentina)

    1999-11-15

    Intermetallic phases and solid solutions in the Zr-rich region of the Zr-Nb-Fe system with low Nb content are studied by Moessbauer spectroscopy complemented with X-ray diffraction, optical and scanning electron microscopy and electron microprobe analysis. The phases found in each sample were those expected from the corresponding binary Zr-Fe system. Furthermore, one of the samples showed a ternary cubic Ti{sub 2}Ni type phase with a similar stoichiometry to the tetragonal Zr{sub 2}Fe compound. Moessbauer parameters were suggested to this phase (IS: - 0.12 mm/s, QS: 0.30 mm/s), to the bcc Zr({beta}) phase (IS: (-0.11 {alpha} 0.01) mm/s, QS: (0.23 {alpha} 0.02) mm/s), and to the hcp Zr({beta}{sup T}) phase (IS: (-0.24 {alpha} 0.02) mm/s, QS: (0.45 {alpha} 0.02) mm/s)

  5. Development of a highly efficient conversion electron Moessbauer spectroscopy (CEMS) detector for low temperature (xPb1-x)Te bilayers

    International Nuclear Information System (INIS)

    Pombo, Carlos Jose da Silva Matos

    2006-01-01

    The 57 Fe Moessbauer spectroscopy is a nuclear, non-destructive technique used for the investigation of structural, magnetic and hyperfine properties of several materials. It is a powerful tool in characterizing materials in physics, metallurgy, geology and biology field areas, especially magnetic materials, alloys and minerals containing Fe. Lately, the Conversion Electron Moessbauer Spectroscopy (CEMS) is widely used in making studies on ultra-thin magnetic films, as well as other nanostructured materials. In case of magnetic nanostructures, low temperature (LT) studies are especially important due to the possibility of dealing with superparamagnetic effects. In this work it was developed a CEMS measurement system for low temperatures ( R ) and an optical cryostat (Model SVT-400, Janis Research Co, USA), from which the project was originally conceived at the Applied Physics / Moessbauer spectroscopy Department from University of Duisburg-Essen, Germany. The LT-CEMS system was fully built, tested and successfully applied in a preliminary characterization of Fe/(Eu x Pb 1-x )Te(111) bilayers with use of a 15 angstrom, 57 Fe probe layer, with reasonable results at sample temperatures as low as 8 K. (author)

  6. 57Fe Moessbauer spectroscopic study of the thermal decomposition of Fe(IO3)3

    International Nuclear Information System (INIS)

    Music, S.; Simmons, G.W.; Leidheiser, H. Jr

    1981-01-01

    Thermal decomposition of iron(III) iodate at temperatures up to 600 deg C has been followed by 57 Fe Moessbauer spectroscopy. The 57 Fe Moessbauer spectrum of iron(III) iodate is characterized by a single absorption peak. A magnetic splitting component of small intensity appears after 42 h heating at 370 deg C. Iron(III) iodate is completely decomposed after 1 h heating at 470 deg C. Moessbauer parameters of the component yielding the magnetic hyperfine split spectrum correspond to α-Fe 2 O 3 with crystal defects. Quantitative experimental data are summarized and discussed. (author)

  7. Characterization of a Copper mineral from Rio Grande do Sul (RS, Brazil) by Moessbauer spectroscopy and chemical analysis

    International Nuclear Information System (INIS)

    Ribeiro, T.H.; Frank, E.; Bristoti, A.

    1980-01-01

    A sample from a copper-based mineral is analysed by Moessbauer spectroscopy. The results are compared with those form X-ray diffraction and microscopic analyses. A graphic correlation between the areas in the chalcopyrite spectra and the copper contents determined by chemical analysis is also made. (C.L.B.) [pt

  8. Characterization of a copper mineral from Rio Grande do Sul (RS, Brazil) by Moessbauer spectroscopy and chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, T H [Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Quimica; Frank, E [Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Fisica; Bristoti, A [Rio Grande do Sul Univ., Porto Alegre (Brazil). Programa de Pos-graduacao de Engenharia Metalurgica e dos Materiais

    1980-01-01

    A sample from a copper-based mineral is analysed by Moessbauer spectroscopy. The results are compared with those from X-ray diffraction and microscopic analyses. A graphic correlation between the areas in the chalcopyrite spectra and the copper contents determined by chemical analysis is also made.

  9. Moessbauer spectroscopy of 151Eu and 153Eu. Applications to structural chemistry and electronic properties of rare-earth compounds

    International Nuclear Information System (INIS)

    Meyer, Marc.

    1975-01-01

    The decrease of the 151 Eu isomer shift on hydrogenation of a dilute EuPd alloy (2.5at% Eu) is discussed in term of the volume effect on the charge density at the nucleus. It is shown from 153 Eu Moessbauer spectroscopy in rare earth titanates that a vibrational anisotropy lead to the observation of a Goldanskii-Karyagin effect [fr

  10. Moessbauer study of proton-exchanged LiNbO3:Fe

    International Nuclear Information System (INIS)

    Engelmann, H.; Andler, G.; Dezsi, I.

    1990-01-01

    Topotactic proton exchange (Li against H) can be achieved by treating LiBnO 3 with appropriate acids. In order to investigate the effect of proton exchange on Fe-impurities we studied LiNbO 3 :Fe powder material treated in sulphuric acid and LiNbO 3 :Fe single crystals treated in benzoic acid by Moessbauer spectroscopy. During the topotactic ion exchange only the Li-ions are exchanged for protons, whereas the Fe-impurities are retained in the material. (orig.)

  11. Moessbauer study of Mn-Zn and Mn ferrites prepared by wet method

    International Nuclear Information System (INIS)

    Michalk, C.

    1985-01-01

    Moessbauer spectroscopy was employed to study Mn-Zn ferrites before and after low-temperature annealing. The unannealed Mn-Zn ferrite prepared by a wet method and also the sintered material after annealing at 400 deg C in air show the presence of paramagnetic clusters. These findings are explained as being due to nonrandom ordering of Fe 3+ and Zn 2+ ions caused by local charge compensation in the neighbourhood of cation vacancies. A change of cation distribution after annealing at relatively low temperatures was observed. 10 refs., 3 figs. (author)

  12. Efficiency analysis of clearance of two types of exogenous iron from the rat brain by Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Polikarpov, D. M., E-mail: polikarpov.imp@gmail.com; Cherepanov, V. M.; Gabbasov, R. R. [National Research Centre, ' Kurchatov Institute' (Russian Federation); Chuev, M. A.; Mischenko, I. N. [Russian Academy of Sciences, Russian Institute of Physics and Technology (Russian Federation); Korshunov, V. A. [Russian Academy of Sciences, Institute of Higher Nervous Activity and Neurophysiology (Russian Federation); Panchenko, V. Y. [National Research Centre, ' Kurchatov Institute' (Russian Federation)

    2013-04-15

    Fe{sub 3}O{sub 4} based ferrofluid was injected transcranially in the ventricle of the rat brain. At 3 months after the injection the rat was sacrificed and the brain was investigated by Moessbauer spectroscopy and histological Perls Prussian blue method. Joint analysis of histological and Moessbauer data confirms that superparamagnetic nanoparticles Fe{sub 3}O{sub 4}, which constituted about 91 % of the iron of the ferrofluid, were cleared from the brain, while the concomitant chemical compound containing ferric ion in the high-spin state, remains intact.

  13. Moessbauer spectroscopy on amorphous Fe/sub x/Ni/sub 80-x/B20 after neutron irradiation

    International Nuclear Information System (INIS)

    Sitek, J.; Miglierini, M.

    1985-01-01

    Amorphous Fe/sub x/Ni/sub 80-x/B 20 glassy alloys (x = 40, 50, 60, and 70) irradiated with fast neutrons in a fluence range of 10 14 to 10 19 cm -2 were investigated by Moessbauer spectroscopy. There were some significant changes in the Moessbauer spectrum parameters of the 10 19 cm -2 irradiated samples except Fe 40 Ni 40 B 20 . This corresponds to a change in the direction of the easy axis of magnetization. The measurements show that the resistance of the Fe-Ni-B system against neutron irradiation improves with increasing Ni content up to a certain point

  14. Analysis of iron storage proteins in chicken liver and spleen tissues in comparison with human liver ferritin by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Oshtrakh, M.I.; Milder, O.B.; Semionkin, V.A.; Malakheeva, L.I.; Prokopenko, P.G.

    2006-01-01

    Characterization of iron storage proteins in liver and spleen from normal chicken and chicken with lymphoid leukemia in comparison with human liver ferritin were considered by Moessbauer spectroscopy (preliminary results). Small differences in Moessbauer hyperfine parameters for both normal and lymphoid leukemia chicken liver and spleen were observed. The value of quadrupole splitting for human liver ferritin was higher than those for chicken tissues. A decrease of iron content in lymphoid leukemia chicken tissues was also found, however, the reason of this fact (pathology or feeding) was not clear yet. (author)

  15. A Moessbauer spectroscopic study of stannosilicate and ferrisilicate glasses

    International Nuclear Information System (INIS)

    Appleyard, P.G.

    2000-02-01

    Silicate glasses of variable composition, containing tin and iron have been studied using Moessbauer spectroscopy. The glass samples consisted of 3 basic groups; binary stannosilicate glasses, ternary stannosilicate glasses and ternary ferrisilicate glasses. The binary stannosilicate glasses were a simple x SnO + (1-x) SiO 2 composition, with x ranging from 16.5% to 67.7% mole. The ternary stannosilicate glasses followed a nominal compositional range of 0.5 SiO 2 + (0.5-x) SnO + x RO, where RO is modifier oxide. Several series of ternary stannosilicates were manufactured, with each series containing a different modifier type. The modifiers chosen were; group I metal oxides of Li, Na, K and Rb, group II metal oxides of Mg, Ca and Sr and group III metal oxide of Al. Two series of ternary ferrisilicate glasses were manufactured following nominal compositional ranges of (0.7-x) SiO 2 + x Fe 2 O 3 + 0.3 Na 2 O and 0.7 SiO 2 + xFe 2 O 3 + (0.3-x) Na 2 O. In the majority of the stannosilicate glasses, the Sn was shown to exist primarily in the Sn(II) valence state. The Moessbauer centre shift and quadrupole splitting of the Sn(II) were shown to possess a dependence on sample concentration, this being weak in the binary glasses, but large and distinct in the ternary glasses. The isomer shift and quadrupole splitting slowly decreased with increasing modifier concentration in the ternary glasses. The rate of this decrease was proportional to the Z/radius of the modifier ion. Variable temperature experiments on a large selection of the glasses revealed that the Sn(II) isomer shift and quadrupole splitting possessed positive and negative dependencies on temperature respectively. The increase in isomer shift is consistent with the effects of thermal expansion and an increase in pressure at the Sn site. The decrease in quadrupole splitting is also consistent with thermal expansion of the Sn-O bonds. The temperature dependence of the isomer shift was incorporated into the

  16. Moessbauer spectrometry study and metallography of paramagnetic phases from zirconium-iron system

    International Nuclear Information System (INIS)

    Freitas Brandao Bittencourt, C. de.

    1976-01-01

    Binary alloys of zirconium with 3 to 23% of iron by weight, were made by diffusion at 875 0 C of iron onto thin plates of zirconium. Moessbauer spectroscopy and optic metallography indicated the phases Zr 2 Fe and Zr 4 Fe, the bulk of which probably formed during the diffusion. These phases were confirmed by electron probe microanalysis. Moessbauer spectra showed quadrupole doublets with the same hyperfine interaction parameters in both phases, but with clearly distinct asymmetries. (author)

  17. Moessbauer spectroscopic study of iron in Japanese cedar bark (Paper No. HF-02)

    International Nuclear Information System (INIS)

    Singh, T.B.; Ichikuni, M.

    1990-02-01

    The bark samples of Japanese cedar collected from mountainous and urban areas were characterised by Moessbauer spectroscopy. The Moessbauer spectra showed that iron in the bark samples was distributed among paramagnetic Fe 2+ , Fe 3+ and magnetic iron and their relative abundance changed appreciably from one area to other. Further, low Fe 2+ /Fe 3+ ratio and high magnetic iron in urban samples indicated an influence of human activities. (author). 1 tab., 1 fig

  18. Investigation of the chemical effects of nuclear transformations by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Nagy, G.A.

    1978-01-01

    Moessbauer spectroscopy proved to be a very successful method for the investigation of the effect of nuclear transformations in solid matrixes. This method makes possible the observation of the atoms to be investigated without the dissolution of the sample i.e. without interfering with the eventual intermediates or their environment, ensuring thus ''in situ'' analysis. The method besides the informations concerning the chemical state of the derivative gives data concerning its immediate environment and its site in the crystal lattice. Products having a very short lifetime can be observed, too. Though the method is suitable only for the investigation of such nucleogenetic nuclei which are at the same time also Moessbauer atoms, the method has several times given fundamental information on the chemical and crystal-structural effects of transformations in solid compounds. Isotopes from nuclear reactions are in general pushed back at a high kinetical energy during their formation, and the method makes possible to deduce the consequences of this push-back effect and of radioactive decays and nuclear reactions. A separate chapter summarizes the recent statements concerning the consequences of the electron capture in solid cobalt compounds, the consequences of the isomer transition of Sn-119 in solid tin compounds etc. (P.J.)

  19. Multi-channel data acquisition and processing system for moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Jin Ge; Yang Yanming

    1987-01-01

    A multi-channel data acquisition and processing system for moessbauer spectroscopy is described, which consists of an intelligent interface and a BC3-80 microcomputer. The system has eight data channels, each channel contains a counting circuit and a memory. A Z80-CPU is used as a main unit for control and access. The microcomputer is used for real-time displaying spectrum, saving the data to disk, printing data and data processing. The system is applicable to a high counting rate multi-wire proportional chamber. It can increase greatly the counting rate for measuring moessbauer spectrum. The signals of each wire in the chamber go through a corresponding amplifier and a differential discriminator and are recorded by a corresponding data channel, the data of each channel is added by the microcomputer. In addition, two channels can be used to measure an absorption and a scattering spectrum at the same time and the internal and the surface information of the sample are obtained simultaneously

  20. Moessbauer study of corrosion induced by acid rain

    International Nuclear Information System (INIS)

    Arshed, M.; Hussain, N.; Siddiqui, M.; Anwar-ul-Islam, M.; Rehman, S.; Butt, N.M.

    1997-01-01

    Strictly speaking acid rain refers to wet precipitation of pollutants S0/sub 2/SO/sub 3/ and NO/sub x/HNO/sub 3/ which have dissolved in cloud and rain droplets to from sulphuric and nitric acids. Acid rain has seriously damaged pine and spruce forests in Canada, USA and Europe. In these areas it has caused damage to buildings, reduced fish population due to acidification of lakes and rivers, and affected health of human beings as a result of poor water quality. The corrosion products formed in a simulated acid rain environment have been identified with transmission Moessbauer spectroscopy using a /sup 57/Co source. They were found to be gamma-FeOOH, alpha-FeOOH, gamma-Fe/sub 2/O/sub 3/ and a phase with unfamiliar parameters which seems to be amorphous in nature and can be considered as an intermediate phase. (author)

  1. Moessbauer studies on the paramagnetic porton of alkidirat meteorite

    International Nuclear Information System (INIS)

    Kamal, Huda Mohamed

    1995-11-01

    This work was performed on a sample from alkidirat meteorite which fell west of Sudan by means of Moessbauer effect spectrometer. results showed the absence of transition temperature from the paramagnetic state to the magnetic state in the temperature range from 300K down to 16K. Also, it was found that olivine and ortho pyroxene exist together in site M 1 , while clinothyroxene exists alone in site M 2 . Formula for the composition of ortho pyroxene in the sample were also obtained and they were in good agreement with previous studies. The disorder parameter was also calculated and it showed that the pyroxene present in the sample is well-ordered.(Author)

  2. High field Moessbauer study of dilute Ir-(Fe) alloys

    International Nuclear Information System (INIS)

    Takabatake, Toshiro; Mazaki, Hiromasa; Shinjo, Teruya.

    1981-01-01

    The magnetic behavior of very dilute Fe impurities in Ir has been studied by means of Moessbauer measurement in external fields up to 80 kOe at 4.2 K. The saturation hyperfine field increases in proportion to the external field up to the maximum magnetic field available. This means that for a localized spin fluctuation system IrFe, the effective magnetic moment associated with Fe impurities is induced in proportion to the external field. No anomalous spectrum was observed with a very dilute sample (--10 ppm 57 Co), indicating that the interaction between impurities is responsible for the anomalous spectrum previously observed with a less homogeneous sample. (author)

  3. Phase analysis of Fe-nanowires encapsulated into multi-walled carbon nanotubes via 57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ruskov, T.; Spirov, I.; Ritschel, M.; Mueller, C.; Leonhardt, A.; Ruskov, R.

    2007-01-01

    We have performed morphological analysis of samples of Fe-nanowires encapsulated into aligned multi-walled carbon nanotubes (Fe-MWCNT) via 57 Fe Moessbauer spectroscopy. The aligned Fe-MWCNTs were obtained by pyrolysis of ferrocene onto an oxidized Si substrate. Transmission Moessbauer spectroscopy (TMS) and back scattered conversion electron Moessbauer spectroscopy (CEMS) were applied in order to distinguish different Fe-phases and their spatial distribution within the whole sample and along the tubes' height. A characterization (on a large spatial scale) of the aligned CNT samples were performed by obtaining TMS spectra for selected spots positioned at different locations of the sample. While the total Fe content changes considerably from one location to another, the γ-Fe/α-Fe phase ratio is constant onto a relatively large area. Using TMS and CEMS for all aligned Fe-MWCNTs samples it is also shown that along the CNT axes, going to the top of the nanotube the relative content of the γ-Fe phase increases. Going to the opposite direction, i.e. towards the silicon substrate, the relative content of the Fe 3 C phase increases, that is in agreement with our previous works. The results of an additional Moessbauer spectroscopy experiment in TMS and CEMS modes performed on a non-aligned sample support the conclusion that in our case the iron phases in the channels of carbon nanotubes are spatially separated as individual nanoparticles. The relative intensity ratio of the α-Fe phase Moessbauer sextets show good magnetic texture along nanotubes axis for one of the aligned samples and the lack of such orientation for the others. (authors)

  4. Moessbauer spectroscopic study on inorganic compounds. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Masashi; Kitazawa, Takafumi; Nanba, Hiroshi; Yoshinaga, Tomohiro; Nakajima, Norio; Sumisawa, Yasuhiro; Takeda, Masuo [Toho Univ., Funabashi, Chiba (Japan). Faculty of Science; Sawahata, Hiroyuki; Ito, Yasuo

    1998-01-01

    {sup 166}Er and {sup 127}I Moessbauer spectra were observed. {sup 166}Er Moessbauer spectrum of Er metal and 9 compounds were measured by {sup 166}Ho/Y{sub 0.6}Ho{sub 0.4}H{sub 2} source at 12K and the parameters such as e{sup 2}qQ(mm s{sup -1}), Heff(T) and {tau}(ns) were determined. The relaxation time of ErCl{sub 3}{center_dot}6H{sub 2}O was 0.7ns, long, but that of ErCl{sub 3} was 10 ps, short time. {sup 127}I Moessbauer spectrum of PhI(O{sub 2}CR){sub 2} (R=CH{sub 3}, CHF{sub 2}, CH{sub 2}Cl, CHCl{sub 2}, CCl{sub 3}, CH{sub 2}Br, CHBr{sub 2} and CBr{sub 3}) were observed and compared with that of R`{sub 3}Sb(O{sub 2}CR){sub 2} was similar to that of PhI(O{sub 2}CR){sub 2}. The correlation coefficient between e{sup 2}qQ({sup 127}I) and Mulliken population of carboxylic hydrogen atom of R{sub 2}CO{sub 2}H was -0.87. The relation between the hypervalent bond of O-I-O and that of O-Sb-0 was shown by the equation: e{sup 2}qQ({sup 121}Sb)/mm s{sup -1} = -47.2 + 1.32 e{sup 2}qQ({sup 127}I)/mm s{sup -1}. Hypervalent iodine complex such as (PhI(py){sub 2}){sup 2+} salt and E-Sb-I (E=O, I, N and C) were studied, too. (S.Y.)

  5. Room temperature 57Fe Moessbauer spectroscopy of ordinary chondrites from the Atacama Desert (Chile): constraining the weathering processes on desert meteorites

    International Nuclear Information System (INIS)

    Valenzuela, M.; Abdu, Y.; Scorzelli, R. B.; Duttine, M.; Morata, D.; Munayco, P.

    2007-01-01

    We report the results of a study on the weathering products of 21 meteorites found in the Atacama Desert (Chile) using room temperature 57 Fe Moessbauer spectroscopy (MS). The meteorites are weathered ordinary chondrites (OCs) with unknown terrestrial ages and include the three chemical groups (H, L, and LL). We obtained the percentage of all the Fe-bearing phases for the primary minerals: olivine, pyroxene, troilite and Fe-Ni metal, and for the ferric alteration products (composed of the paramagnetic Fe 3+ component and the magnetically ordered Fe 3+ components) which gives the percentage of oxidation of the samples. From the Moessbauer absorption areas of these oxides, the terrestrial oxidation of the Atacama OC was found in the range from ∼5% to ∼60%. The amount of silicates as well as the opaques decreases at a constant rate with increasing oxidation level.

  6. High pressure Moessbauer spectroscopy with nuclear resonant forward scattering of synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nasu, Saburo [Osaka Univ., Toyonaka (Japan). Faculty of Engineering Science

    1996-04-01

    The first observation of the pressure-induced transition from the antiferromagnetic to the ferromagnetic SrFeO{sub 3} was succeeded by measuring Moessbauer spectroscopy under high pressure produced by the diamond anvil cell (DAC). Sample is a polycrystal powder of antiferromagnetic SrFe0{sub 3} with the Neel temperature T{sub N}=140 K, the cubic system and perovskite type crystal. The average pressures used were 44 GPa and 74 GPa (300 K). SrFeO{sub 3} is paramagnetic material at 300 K, but the Neel temperature increases more than 300 K under high pressure and the quantized axis turns to the external magnetic field, so that we take it as it means the system displaying the phase transition to the ferromagnet. By the method, we can practice the measurement at low and high temperature under the external magnetic field by using the polarized light source. (S.Y.)

  7. A method of Moessbauer Fourier spectroscopy for determination of the biopolimer coordinate correlation functions

    International Nuclear Information System (INIS)

    Basovets, S.K.; Krupyanskij, Yu.F.; Kurinov, I.V.; Suzdalev, I.P.; Goldanskij, V.I.; Uporov, I.V.; Shaitan, K.V.; Rubin, A.B.

    1988-01-01

    A method of Moessbauer Fourier spectroscopy is developed to determine the correlation function of coordinates of a macromolecular system. The method does not require the use of an a priori dynamic model. The application of the method to the analysis of RSMR data for human serum albumin has demonstrated considerable changes in the dynamic behavior of the protein globule when the temperature is changed from 270 to 310 K. The main conclusions of the present work is the simultaneous observation of low-frequency (τ≥10 -9 sec) and high-frequency (τ -9 sec) large-scaled motions, that is the two-humped distribution of correlation times of protein motions. (orig.)

  8. Moessbauer spectroscopy in nanocrystalline Fe88Zr7B4Cu1

    International Nuclear Information System (INIS)

    Navarro, I.

    1995-01-01

    Local structural changes during the crystallization process of initially amorphous Fe 88 Zr 7 B 4 Cu 1 (at %) have been investigated by means of Moessbauer spectroscopy at room temperature. In the as-cast state, no ferromagnetic phase has been detected. The crystallization process has been found to consist of two steps. In the first step (after annealing up to 500-650 C), precipitation of α-Fe (47-59%) takes place. The remaining amorphous matrix evolves to a ferromagnetic phase, although a small fraction of non-ferromagnetic phase (5-8%) is also detected during the crystallization process. Annealing at more elevated temperatures completely crystallizes the amorphous phase and three new crystalline subspectra are found. Correlations between the soft magnetic properties and these local structural changes are also discussed. ((orig.))

  9. Seasonal variation of iron speciation in a pearl-raising bay sediment by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Kuno, Akihito; Matsuo, Motoyuki; Chiba, Satoshi; Yamagata, Yoichi

    2008-01-01

    Ago Bay in Mie Prefecture, central Japan, is world-famous for the site of Mikimoto pearl culture, but recently the production of pearls has considerably declined. Environmental deterioration of the bay is suspected of having caused the decline. The periodic investigation into iron speciation of the bay sediment by 57 Fe Moessbauer spectroscopy revealed its high pyrite (FeS 2 ) content from the surface to the 20-cm depth. The pyrite in the surface sediment decreased only in spring, three months after the dissolved oxygen in the bottom water was at maximum. Such oxygen-consuming material as pyrite accumulated through long-term biotic activity is a most-likely explanation for the prolonged environmental deterioration of the bay, which appears in the high chemical oxygen demand (COD) of the sediment. (author)

  10. Neutron Activation Analysis and Moessbauer Correlations of Archaeological Pottery from Amazon Basin for Classification Studies

    International Nuclear Information System (INIS)

    Bellido, A. V. B.; Latini, R. M.; Nicoli, I.; Scorzelli, R. B.; Solorzano, P. M.

    2011-01-01

    The aim of the present work was to investigate the correlation between data obtained by means of two analytical methods, instrumental neutron activation analysis (INAA) and Moessbauer Spectroscopy of pottery samples combined with multivariate statistical analysis in order to optimize quantitative analysis in the classification studies. Ceramics recently discovered in archaeological earth circular structures sites in Acre state Brazil. 199 samples were analyzed by INAA, allowing simultaneous determination of twenty elements chemical concentrations, and 44 samples by using Moessbauer Spectroscopy, allowing the determination of fourteen hyperfine parameters. For the correlation study, data were treated by two multivariate statistical methods: cluster analysis for the classification and the principal component analysis for the data correlations. INAA data show that some of REE (rare earth elements) were the discriminating variables for this technique. Mossbauer parameters that exhibit the same behavior are being investigated, remarkable improve can be seem for the combined REE and the Mossbauer variables showing a good results considering the limited number of samples. This data matrix is being used for the understanding in the studies of classification and provenance of ceramics prehistory of the Amazonic basin.

  11. Moessbauer characteristics of glauconitisation

    International Nuclear Information System (INIS)

    Kuzmann, E.; Weiszburg, T. G.; Toth, E.; Garg, V. K.

    2008-01-01

    57 Fe Moessbauer spectroscopy, X-ray diffraction and local (WDX, EDX) and bulk chemical methods (ICP-AES complemented with Fe 2+ titration) were used to study glauconites originating from three sandstone samples (NY1, NY3 and EWT) of the Upper Oligocene Eger Formation (Northern Hungary). The, during glauconitisation, increasing aggregate density and magnetic susceptibility offered a unique possibility to separate grains of different evolutionary stage from the same glauconite population. 57 Fe Moessbauer spectra of both structurally and chemically well characterised glauconite fractions were decomposed into four doublets. Two-two of the doublets were assigned to octahedral Fe 2+ and octahedral Fe 3+ . Fe 2+ /Fe values determined by Moessbauer measurements were used for the calculation of the chemical formula of glauconite samples [including octahedral occupancy (B O ) and octahedral charge (X O ) as well]. The gradual increase of Fe 2+ /Fe was documented with the increase of aggregate density in correlation with the foregoing of glauconitisation. Our results give a quantitative demonstration that octahedral occupancy (B O ) decrease and the substitution of octahedral Al by Fe 2+ are the major processes allowing the interlayer K incorporation during glauconitisation. The systematic crystalchemical evolution as reflected in the systematic changes of the Moessbauer data are discussed in terms of the subsequent steps of glauconitisation.

  12. Moessbauer study of small amounts of iron in graphite, around the diamond-graphite pressure-temperature stability region

    International Nuclear Information System (INIS)

    Oliveira, C.L.S. de; Silva, M.T.X.; Vasquez, A.; Jornada, J.A.H. da

    1991-01-01

    An exploratory Moessbauer spectroscopy study of the Fe-C system in the C rich region, prepared by high pressure-high temperature treatment near the graphite-diamond stability line, was made. The results obtained for the different processing conditions give no evidence of Fe intercalation in graphite. The presence of some water in the cell produced hydrated Fe complexes, which can explain the deleterious effect of water or hydrogen in the high pressure diamond synthesis. (orig.)

  13. A 197Au and 57Fe Moessbauer study of the roasting of refractory gold ores

    International Nuclear Information System (INIS)

    Wagner, F.E.; Marion, P.

    1989-01-01

    The transformation of chemically bound gold into metallic gold during industrial scale roasting of an arsenical gold ore concentrate from the Fairview Mine, Eastern Transvaal, has been studied quantitatively by 197 Au Moessbauer spectroscopy. The iron compounds in the concentrate, mainly FeAsS and FeS 2 , and their transformations during roasting have been studied by 57 Fe Moessbauer spectroscopy. The bound gold is found to convert into the metal in parallel to the decomposition of FeAsS and the increase in cyanide leachability. This shows that the refractory character of the ore is caused by the chemical bonding of the gold rather than by the physical inclusion of small, discrete metallic particles in the matrix of FeAsS or FeS 2 . The ratio of the f-factors of gold bound in the FeAsS component of a refractory ore and of metallic gold was determined to be f(Au:FeAsS)/f(Au)=1.48 ± 0.09. (orig.)

  14. Progress in Investigation of WWER-440 Reactor Pressure Vessel Steel by Gamma and Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Hascik, J.; Slugen, V.; Lipka, J.; Hinca, R.; Toth, I.; Groene, R.; Uvacik, P.; Kupca, L.

    1998-01-01

    Gamma spectroscopic analyse and first experimental results of original irradiated reactor pressure vessel surveillance specimens are discussed in. In 1994, the new ''Extended Surveillance Specimen Program for nuclear Reactor Material Study'' was started in collaboration with the nuclear power plants (NPP) V-2 Bohunice (Slovakia). The first batch of MS samples (after 1 year, which is equivalent to 5 years of loading RPV-steel) was measured and interpreted using the new four components approach with the aim to observe microstructural changes due to thermal and neutron treatment resulting from operating conditions in NPP. The systematic changes in the relative areas of Moessbauer spectra components were observed. (author)

  15. Chemical-mineralogical characterization and Moessbauer spectroscopy of aquamarine from Pedra Azul, Northeast of Minas Gerais

    International Nuclear Information System (INIS)

    Viana, Rubia Ribeiro; Jordt-Evangelista, Hanna; Costa, Geraldo Magela da

    2001-01-01

    Aquamarines from three pegmatites located the vicinities of the Pedra Azul city, Minas Gerais state, were investigated in terms of chemical composition, physical properties and Moessbauer spectroscopy. The small lenticular pegmatite bodies are usually less than 5 m wide and exhibit a conspicuous mineralogical and textural zoning. The last thermal event in these pegmatites, determined by K-Ar method in muscovite, is of Neo proterozoic age, coincident with the late stages of the Brasiliano tectono- metamorphic cycle. Chemical analyses showed that sodium is the alkali with higher contents in the aquamarines, thus enabling their classification as sodic beryls. In zoned samples there is an increase of Fe as well as Mn from center to border, while no systematic variation could be detected for other elements. The specific gravity of 2.72 to 2.80 g/cm 3 is higher than the values determined for samples from other pegmatites of Minas Gerais. The refraction indices are ne=1.569 - 1.579 and NW= 1.573 - 1.581 and the birefringence varies from 0.002 to 0.008. The refraction indices increase with the Be O content. The color of aquamarines varies from medium to light blue, sometimes greenish blue. Moessbauer spectra obtained at room temperature and at 80 K show that Fe 2+ is the main chromophore-ion and suggest that the iron is present in octahedral sites as well as in the structural channels. Moessbauer spectra also indicate that the incorporation of Fe 3+ may cause a shift from deep blue to light blue colors. Based on their aquamarine composition the pegmatites were classified as barren, poor in rare alkalis (Li, Rb, Cs) and therefore little differentiated. The relatively simple mineralogy and the lack of lithium minerals such as lepidolite and spodumene confirm this classification. Thus, the composition of beryl can be used as a tracer for the prospection of pegmatites with different degrees of differentiation and consequently with different types of mineralization. (author)

  16. Moessbauer spectroscopy study of the synthesis of SnFe2O4 by high energy ball milling (HEBM) of SnO and α-Fe2O3

    International Nuclear Information System (INIS)

    Uwakweh, Oswald N C; Perez Moyet, Richard; Mas, Rita; Morales, Carolyn; Vargas, Pedro; Silva, Josue; Rossa, Angel; Lopez, Neshma

    2010-01-01

    The formation of single phase nanoparticles of spinel structured ferrite, SnFe 2 O 4 , by mechanochemical syntheses using HEBM of stoichiometric amounts of solid SnO and α-Fe 2 O 3 with acetone as surfactant was achieved progressively as function of ball milling time. Single phase SnFe 2 O 4 formation commenced from five hours of continuous ball milling, and reached completion after 22 hours, thereby yielding a material with a lattice parameter of 8.543 A, and particle size of 10.91 nm. The coercivity was 4.44 mT, magnetic saturation value of 17.75 Am 2 /kg, and remanent magnetizations of 1.50 Am 2 /kg, correspondingly. The nanosized particles exhibited superparamagnetic behavior phenomenon based on Moessbauer spectroscopy measurements. The kinetic analyses based on the modified Kissinger method yielded four characteristic stages during the thermal evolution of the 22 hours milled state with activation energies of 0.23 kJ/mol, 2.52 kJ/mol, 0.024 kJ/mol, and 1.57 kJ/mol respectively.

  17. Mineralogy of the clay fraction of soils from the moray cusco archaeological site: a study by energy dispersive X-ray fluorescence, X-ray diffractometry and Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ceron Loayza, Maria L., E-mail: malucelo@hotmail.com; Bravo Cabrejos, Jorge A.; Mejia Santillan, Mirian E. [Universidad Nacional Mayor de San Marcos, Laboratorio de Analisis de Suelos, Laboratorio de Espectroscopia Moessbauer, Facultad de Ciencias Fisicas (Peru)

    2011-11-15

    The purpose of this work is to report the advances in the elemental and structural characterization of the clay fraction of soils from the terraces of the Moray Archaeological site, located 38 km north of the city of Cusco, Cusco Region. One sample was collected from each of the twelve terraces of this site and its clay fraction was separated by sedimentation. Previously the pH of the raw samples was measured resulting that all of the samples were from alkaline to strongly alkaline. Energy dispersive X-ray fluorescence (EDXRF) was used for the elemental characterization, and X-ray diffractometry (XRD) and transmission Moessbauer spectroscopy (TMS), using the {gamma} 14.4 keV nuclear resonance transition in {sup 57}Fe, were used for the structural characterization of the clays and clay minerals present in each sample. The EDXRF analyses of all the samples show the presence of relatively high concentrations of sulfur in some of the samples and relatively high concentrations of calcium in all of the samples, which may be related to the high alkalinity of the samples. By XRD it is observed the presence of quartz, calcite, gypsum, cronstedtite, 2:1 phyllosilicates, and iron oxides. The mineralogical analysis of Fe by TMS shows that it is present in the form of hematite and occupying Fe{sup 2 + } and Fe{sup 3 + } sites in phyllosilicates, cronstedtite, and other minerals not yet identified.

  18. Localization of the antimony impurity atoms in the PbTe lattice determined by the Moessbauer emission spectroscopy

    International Nuclear Information System (INIS)

    Masterov, V.F.; Nasredinov, F.S.; Nemov, S.A.; Seregin, P.P.; Troitskaya, N.N.; Bondarevskij, S.I.

    1997-01-01

    The 119 Sb ( 119m Sn) emission Moessbauer spectroscopy has shown that a localization of the antimony impurity atoms in the PbTe lattice is affected by the conductivity type of the host material, the antimony atoms occupied mainly anion and cation sites in n-type and p-type samples, respectively. The 119 Sn impurity in the anion sublattice of PbTe formed an decay. Its charge state was shown to be independent of the Fermi level position

  19. Behaviour of Ca2Fe2O5 with Nb substitution and sintering temperatures seen by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Duhalde, S.; Saragovi, C.; Moraes, I.J.; Terrile, M.C.; Francisco, R.H.P.

    1991-01-01

    Moessbauer spectroscopy of samples of Ca 2 Fe 2-x Nb x O 5+x with x values ranging from 0 to 0.8 and sintering temperatures of 1200degC and 1300degC shows the presence of two magnetic fields and a paramagnetic signal. The behaviour of the parameters as a function of x and of the sintering temperatures are discussed and compared with XRD results. (orig.)

  20. The elementary concentration and the behavior of the iron in Cuban agricultural soils by means of the Neutron activation Analysis and Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Furet, N. R.; Oddone, M.; Orihuela, D.L.

    1999-01-01

    Representative samples from Cuban agricultural soils, which have been benefited with industrial waste are studied by means of the methods of the Analysis for Instrumental Neutronic Activation and Moessbauer Spectroscopy. The elemental contents of Na, K, Ca, Fe, Cr, etc. are determined, and the influence of the industrial waste in the elemental concentrations is valued. The behavior of the iron is studied, like one of the important elements in several processes of development of the plants. The oxidation and coordination states of the Fe in soils are studied

  1. An iron-57 Moessbauer spectroscopic study of titania-supported iron- and iron-iridium catalysts

    International Nuclear Information System (INIS)

    Berry, F.J.; Jobson, S.

    1992-01-01

    57 Fe Moessbauer spectroscopy shows that titania-supported iron is reduced by treatment in hydrogen at significantly lower temperatures than corresponding silica- and alumina-supported catalysts. The metallic iron formed under hydrogen at 600deg C is partially converted to carbide by treatment in carbon monoxide and hydrogen. In contrast to its alumina- and silica-supported counterparts, the remainder of the titania-supported iron is unchanged by this gaseous mixture. The 57 Fe Moessbauer spectra of EXAFS show that iron and iridium in the titania-supported iron-iridium catalysts are reduced in hydrogen at even lower temperatures and, after treatment at 600deg C, are predominantly present as the iron-iridium alloy. The treatment of these reduced catalysts in carbon monoxide and hydrogen is shown by Moessbauer spectroscopy and EXAFS to induce the segregation of iron from the iron-iridium alloy and its conversion to iron oxide. (orig.)

  2. A Moessbauer study on the interaction between biomolecular lipid membranes and ferric ferrous ions

    International Nuclear Information System (INIS)

    Karvaly, B.; Badinka, C.; Keszthelyi, L.; Erdei, L.

    1975-01-01

    The results of Moessbauer experiments made on liposome systems of a large specific area are presented. In the study lecithin was used as a membrane-forming material. The measurements were carried out on frozen liposome systems, at various 57 Fe/lipid concentration ratios, pH values and temperatures. Since the presence of liposomes had no noticeable influence on the Moessbauer spectra of Fe 2+ ions, only lecithin Fe 3+ systems were considered. Moessbauer spectra in case of Fe 3+ solutions with lecithin showed marked quadrupole splitting (exhibiting an anomalous temperature dependence) which is not shown in case of pure Fe 3+ solution. (Z.S.)

  3. Hyperfine interactions by Moessbauer effect

    International Nuclear Information System (INIS)

    Constantinescu, S.

    1980-01-01

    Moessbauer spectroscopy has been used to investigate hyperfine interactions in materials endowed with complex electromagnetic crystallographic structures. Such structures (Me 3 B 7 O 13 X boracite-type systems, for instance), equally interesting from both scientific and applications viewpoint, are drawing a special attention lately on account of their being examined by means of increasingly refined experimental techniques. In view of the wide prospects of using these materials in various practical fields, this thesis counts among the studies aiming to ameliorate the methods of processing and determining the Moessbauer spectra parameters, characterized by complex hyperfine interactions, as well as among the studies of electric, magnetic and crystallographic investigation of the Moessbauer nucleus neighbourhood, in boracite-type structures. (author)

  4. Moessbauer study of iron-cobalt-rhodium spinels

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, C D; Smith, P A; Karnes, C M; Shepard, W A [Ithaca Coll., NY (USA). Dept. of Physics

    1980-01-01

    Moessbauer source and absorber studies have been carried out on the spinel system CoFesub(x)Rhsub(2-x)O/sub 4/ for x 0.005, 0.3, 0.5, 1.0, 1.2 and 1.5. For 0.005 =< x =< 1.2, the cation distribution is normal with Co/sup 2 +/ on A sites. At x = 1.5, the distribution is nearly inverse. In the cases x = 0.005 and 0.3, iron on the B sites does not produce a quadrupole doublet indicating that the B sites are cubic which is contrary to the usual case in spinels.

  5. Moessbauer studies of blood diseases: thalassemia and malaria

    International Nuclear Information System (INIS)

    Bauminger, E.R.

    1988-01-01

    In 57 F Moessbauer studies of blood samples obtained from patients with thalassemia large amounts of iron, yielding a well defined spectrum, different from that obtained in oxy - or deoxy-hemoglobin, were found. The additional iron component was identified as due to ferritin - the iron storage protein. The amounts of ferritin-like iron were comparable to those of hemoglobin iron and were especially large in reticulocytes. Desferral was found to remove ferritin-like iron from serum, but not from red blood cells. In malaria, a parasite induced blood disease, the iron containing compound in the malarial pigment in rats infected by Plasmodium berghei was found to be trivalent high spin, different from any known iron porphyrin, yet was found to be similar to hemin in human blood cells infected by P. falciparum. The difference in the spectra obtained in RBC infected with drug sensitive and drug resistance strains and the effect of medication on the spectra is discussed. (author)

  6. Moessbauer studies on the paramagnetic porton of alkidirat meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Huda Mohamed [Department of Physics, Faculty of Science, University of Khartoum, Khartoum (Sudan)

    1995-11-01

    This work was performed on a sample from alkidirat meteorite which fell west of Sudan by means of Moessbauer effect spectrometer. results showed the absence of transition temperature from the paramagnetic state to the magnetic state in the temperature range from 300K down to 16K. Also, it was found that olivine and ortho pyroxene exist together in site M{sup 1}, while clinothyroxene exists alone in site M{sup 2}. Formula for the composition of ortho pyroxene in the sample were also obtained and they were in good agreement with previous studies. The disorder parameter was also calculated and it showed that the pyroxene present in the sample is well-ordered.(Author) 37 refs. , 2 tabs. , 19 figs.

  7. Application of the Moessbauer spectroscopy to the investigation of the proton irradiation effects in several iron compounds

    International Nuclear Information System (INIS)

    Kopcewicz, M.; Kotlicki, A.

    1975-01-01

    The results of a study into the influence of proton irradiation on the Moessbauer effect in FeSO 4 x 7H 2 O, K 4 [Fe(CN) 6 ] x 3H 2 O and K 3 [Fe(CN) 6 ] are reported. In the interpretation of the effect observed, the 'spike' model was applied. Chemical decomposition processes due to proton irradiation and formation of the superparamagnetic state of metallic iron were investigated. A Moessbauer observation of interstitial Fe 2+ ions in irradiated FeSO 4 x 7H 2 O was made. (Z.S.)

  8. Moessbauer Study of the Ball Milling Disordering Process of FeAl Intermetallic Compounds

    International Nuclear Information System (INIS)

    Oleszak, Dariusz; Bruna, Pere; Crespo, Daniel; Pradell, Trinitat

    2005-01-01

    Structural changes during ball milling of ordered Fe50Al50 intermetallic compounds were studied. X-Ray diffraction allowed the computation of a Long Range Order parameter (LRO) which dropped to zero after a short milling time. The initial B2 ordered structure gradually transforms into a disordered BCC structure, with a final crystallite size of about 25 nm. Moessbauer spectroscopy was used for obtaining a Chemical Short Range Order parameter (CSRO). Using a semiempirical n-body noncentral potential a model of the partially disordered B2 structure was built allowing computing the distribution of Quadrupole Splitting during the disordering process. Comparison between experimental and simulated Moessbauer spectra shows a maximum of disorder in the system for 5h milling, related to the highest value of the lattice spacing and the broader quadrupole hyperfine distribution. However, after milling for times longer than 5h, there is a change on the behavior of the experimental data that cannot be explained by the simple disordering process

  9. High-pressure Moessbauer study of perovskite iron oxides

    CERN Document Server

    Kawakami, T; Sasaki, T; Kuzushita, K; Morimoto, S; Endo, S; Kawasaki, S; Takano, M

    2002-01-01

    The perovskite oxides CaFeO sub 3 and La sub 1 sub / sub 3 Sr sub 2 sub / sub 3 FeO sub 3 have been investigated by high-pressure sup 5 sup 7 Fe Moessbauer spectroscopy. The critical temperatures of the charge disproportionation (CD) and the magnetic order (MO) have been determined as a function of pressure. In CaFeO sub 3 the CD (2Fe sup 4 sup + -> Fe sup 3 sup + + Fe sup 5 sup +) occurs at an almost constant temperature of 290 K in the pressure range of 0-17 GPa. Above 20 GPa, the CD is suppressed. The MO temperature of 125 K at an ambient pressure rises to 300 K at 34 GPa. In La sub 1 sub / sub 3 Sr sub 2 sub / sub 3 FeO sub 3 the CD (3Fe sup 1 sup 1 sup / sup 3 sup + -> 2Fe sup 3 sup + + Fe sup 5 sup +) and the MO occur at the same temperature up to 21 GPa, which decreases from 207 to 165 K with increasing pressure. Above 25 GPa, however, the MO temperature rises above 400 K.

  10. Moessbauer study of (Benzylideneacetone) Fe(Co)2L complexes with L=CO, phosphines and phosphites

    International Nuclear Information System (INIS)

    Vichi, E.J.S.; Stein, E.

    1988-01-01

    It is established that in iron complexes, both ligand-L-> Fe bonding and Fe -> L back bonding increase the s electron density at the iron nucleus (1), with a consequent decrease in the isomer shift (δ) obtained from the Moessbauer spectrum. Through θ-bonding, electrons are transferred from the ligand to the proper iron orbitals which have, at least, partial 4s character. Through Π-back bonding, d electrons of the metal are transferred to the proper orbitals of the ligand, decreasing the shielding of the metal 3s electrons. So, δ measures the effect of (θ+Π) bonding on s electron density at the iron nucleus. The quadrupole splitting (ΔE q ), which is related to the electric field gradient at the iron nucleus and involves only d or p electrons, measures the effect of (θ-Π) bonding. Here, the results of a Moessbauer spectroscopy study on title complexes are reported. (author)

  11. 197Au Moessbauer study of nano-sized gold catalysts supported on Mg(OH)2 and TiO2

    International Nuclear Information System (INIS)

    Kobayashi, Y.; Nasu, S.; Tsubota, S.; Haruta, M.

    2000-01-01

    We have studied nano-sized Au catalysts supported on Mg(OH) 2 and TiO 2 using 197 Au Moessbauer spectroscopy. 197 Au Moessbauer spectra observed for Au/Mg(OH) 2 catalysts can be decomposed into one singlet with zero isomer shift and several doublets. One of the doublets shows an isomer shift that is typical for Au I , and other doublets are due to Au III . The relative area of the Au I component shows the maximum value for a specimen calcined at 523 K, which also shows the highest catalytic activity

  12. Moessbauer study of amorphous Fe-P alloys

    International Nuclear Information System (INIS)

    Takacs, L.; Toth-Kadar, E.

    1981-01-01

    Preliminary Moessbauer results are represented on electrodeposited Fe-P amorphous alloys. Very broad hyperfine field distributions and relatively large isomer shifts have been found. Problems worth of further investigation are discussed in details. (author)

  13. Ecological aspects of Moessbauer study of iron-containing atmospheric aerosols

    International Nuclear Information System (INIS)

    Kopcewicz, B.; Kopcewicz, M.

    2000-01-01

    Moessbauer spectroscopy was applied to analyze the iron compounds in atmospheric aerosol. Seasonal variations of iron concentration in atmospheric air measured over twenty years in Poland are discussed. It was observed that the concentration of iron sulfides (FeS, FeS 2 ) related to coal combustion dropped significantly, however, concentration of iron oxides and iron oxyhydroxides related to fuel combustion increased

  14. 119Sn Moessbauer spectroscopy in the magnetically diluted Heusler-type systems

    International Nuclear Information System (INIS)

    Ruebenbauer, K.

    1981-01-01

    119 Sn Moessbauer investigations of the ferromagnetically diluted Nisub(2)Mnsub(x)Bsub(1-x)Sn(B=Ti, V) and Pdsub(2)Mnsub(x)Vsub(1-x)Sn Heusler-type systems have been performed and the results are reviewed and discussed. It has been found that distributions of the transferred hyperfine magnetic field as seen by a tin nucleus are very sensitive for a type of the local magnetic interaction in these simple ferromagnets, especially when studied versus the sample temperature. This sensitivity allows to reach some conclusions about the coupling mechanism between localised manganese magnetic moments. Namely, it is concluded that the interaction beyond the second neighbour shell is practically irrelevant for the magnetic ordering process. This very fact means that the free electron approach to the calculation of exchange integrals can not be applied for these particular systems. (Author)

  15. Moessbauer spectroscopy on amorphous Fe/sub x/Ni/sub 80-x/B/sub 20/ after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sitek, J.; Miglierini, M. (Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia))

    1985-05-16

    Amorphous Fe/sub x/Ni/sub 80-x/B/sub 20/ glassy alloys (x = 40, 50, 60, and 70) irradiated with fast neutrons in a fluence range of 10/sup 14/ to 10/sup 19/ cm/sup -2/ were investigated by Moessbauer spectroscopy. There were some significant changes in the Moessbauer spectrum parameters of the 10/sup 19/ cm/sup -2/ irradiated samples except Fe/sub 40/Ni/sub 40/B/sub 20/. This corresponds to a change in the direction of the easy axis of magnetization. The measurements show that the resistance of the Fe-Ni-B system against neutron irradiation improves with increasing Ni content up to a certain point.

  16. Evaluation of accidental coincidences for time-differential Moessbauer-spectroscopy

    International Nuclear Information System (INIS)

    Alflen, M.; Meyer, W.

    1995-01-01

    The accidental coincidences of a measuring system based on time-to-amplitude conversion are considered in some detail for the case of low starting and high stopping rates. Two types of accidental coincidences are distinguished, those carrying time information and those without time information. Neglecting any deadtime effects of the detectors, analytical expressions for the calculation of the time distribution of the random coincidences are evaluated. The analytical expressions have been confirmed by Monte Carlo simulations. The procedure is applied to time-differential Moessbauer spectroscopy in order to extract the time spectra of true coincidences. The measured spectrum in a time channel turns out to be a superposition of the true spectrum (true coincidences), a time integral spectrum (random coincidences), and a weighted superposition of true spectra of other time channels (random but time carrying information). A measurement with a single line 57 Co/Rh-source and single line K[Fe(CN) 6 ].3H 2 O-absorber with stopping rates of 1 MBq shows agreement between the theoretical time-filtered spectra and the corrected measured spectra of true coincidences. ((orig.))

  17. Design and construction of an electromechanical velocity modulator for Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, A. A., E-mail: avelas26@eafit.edu.co; Carmona, A. [Universidad EAFIT, Grupo de Electromagnetismo Aplicado (Colombia); Velasquez, D.; Angel, L. [Universidad EAFIT, Grupo de Optica Aplicada (Colombia)

    2011-11-15

    In this paper we report the design, construction and characterization of an electromechanical velocity modulator for application in Moessbauer spectroscopy. The modulator was constructed with copper coils, Neodymium magnets, steel cores and polymeric membranes. The magnetic field in the driving and velocity sensing stages was analyzed by the finite element method, which showed a linear relation between the magnetic field in the region of motion of both coils and the position of the coils within the steel cores. The results obtained by computational simulation allowed us to optimize geometries and dimensions of the elements of the system. The modulator presented its first resonance frequency at 16.7 Hz, this value was in good agreement with that predicted by a second order model, which showed a resonant frequency of 16.8 Hz. The linearity of the velocity signal of the modulator was analyzed through an optical method, based on a Michelson-Morley interferometer, in which the modulator moved one of the mirrors. Results showed a satisfactory linearity of the velocity signal obtained in the sensing coil, whose correlation with a straight line was around 0.99987 for a triangular reference waveform.

  18. DyNi{sub 2}Mn-magnetisation and Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jianli; Campbell, Stewart James, E-mail: stewart.campbell@adfa.edu.au [University of New South Wales, School of Physical, Environmental and Mathematical Sciences (Australia); Kennedy, Shane Joseph [ANSTO, Bragg Institute (Australia); Dou Shixue [University of Wollongong, Institute for Superconductivity and Electronic Materials (Australia); Wu Guangheng [Chinese Academy of Science, Institute of Physics (China)

    2012-03-15

    The physical properties of DyNi{sub 2}Mn doped with {sup 57}Fe have been investigated by X-ray diffraction, magnetisation (10-300 K) and {sup 57}Fe Moessbauer spectroscopy measurements (5-300 K). DyNi{sub 2}Mn({sup 57}Fe) crystallizes in the MgCu{sub 2}-type cubic structure (Fd{sup }-3m space group). The ordering temperature is found to be T{sub C} = 99(2) K, much higher than those of DyNi{sub 2} ({approx}22 K) and DyMn{sub 2} ({approx}35 K). Analyses of isothermal M-H curves and the related Arrott plots confirm that the magnetic phase transition at T{sub C} is second order. The magnetic entropy change around T{sub C} is 4.0 J/kg K for a magnetic field change of 0 T to 5 T. The spectra above T{sub C} exhibit features consistent with quadrupolar effects while below T{sub C} the spectra exhibit magnetic hyperfine splitting. The Debye temperature for DyNi{sub 2}Mn has been determined as {theta}{sub D} = 200(20) K from a fit to the variable temperature isomer shift IS(T).

  19. Trace cobalt speciation in bacteria and at enzymic active sites using emission Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, A.A.; Antonyuk, L.P.; Smirnova, V.E.; Serebrennikova, O.B. [Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov (Russian Federation); Kulikov, L.A.; Perfiliev, Yu.D. [Laboratory of Nuclear Chemistry Techniques, Department of Radiochemistry, Faculty of Chemistry, Moscow State University (Russian Federation)

    2002-02-01

    {sup 57}Co emission Moessbauer spectroscopy (EMS) allows the chemical state of cobalt, as influenced by its coordination environment, to be monitored in biological samples at its physiological (trace) concentrations. To draw attention to EMS as a valuable tool for speciation of cobalt in biocomplexes, the process of cobalt(II) metabolism in cells of the plant growth-promoting rhizobacterium Azospirillum brasilense Sp245 was investigated using EMS of {sup 57}Co{sup II}-doped bacterial cells. EMS measurements also showed {sup 57}Co{sup II}-activated glutamine synthetase (GS, a key enzyme of nitrogen metabolism, isolated from this bacterium) to have two different cobalt(II) forms at its active sites, in agreement with data available on other bacterial GSs. Chemical after-effects following electron capture by the nucleus of the parent {sup 57}Co{sup II} during the {sup 57}Co{yields}{sup 57}Fe transition, which contribute to the formation of a stabilised daughter {sup 57}Fe{sup III} component along with the nucleogenic {sup 57}Fe{sup II} forms, are also briefly considered. (orig.)

  20. Some antarctic soil cores from Wood Bay characterised by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bertelle, M.; Leotta, G.; Calogero, S.; Constantinescu, S.; Oddone, M.

    1999-01-01

    Marine, lacustrine and terrestrial soil cores, sampled in a restricted area of Wood Bay in Antarctica, were characterised by 57 Fe Moessbauer spectroscopy. The results of X-ray diffraction and instrumental neutron activation analysis are shortly discussed too. The soils, formed by mechanical disaggregation and weathering of rocks of volcanic origin from Mt. Melbourne, consist of alkaline feldspars, olivines, augitic clinopyroxenes, and iron oxides such as haematite, goethite, and magnetite. Lacustrine and terrestrial soils are richer in clinopyroxenes whereas marine soils are richer in olivines. This finding shows that the soils retain a content in olivines and clinopyroxenes comparable to that found in the parent lava outcropped from Mt. Melbourne volcano. The soils appear at the initial stage of weathering. Two main weathering effects are observed: 1. atmospheric oxygen determines the oxidation of the iron(II) present in olivines and clinopyroxenes and the neo-formed iron(III) is mainly retained in silicate sites as structural iron(III); 2. a part of magnetite, present as a primary constituent of the volcanic rocks, is oxidised to bulk haematite and goethite. (authors)

  1. Highly effective portable beta spectrometer for precise depth selective electron Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Aldiyarov, N.U.; Kadyrzhanov, K.K.; Seytimbetov, A.M.; Zhdanov, V.S.

    2007-01-01

    Full text: More broad application of the nuclear-physical method of precise Depth Selective Electron Moessbauer Spectroscopy (DS EMS) is limited by insufficient accessibility of highly-effective beta spectrometers with acceptable resolution. It should be mentioned that the method DS EMS is realized at a combined installation that consists of a highly-effective beta spectrometer and a conventional portable nuclear gamma-resonance spectrometer. Yet few available beta spectrometers have sophisticated design and controlling; in most cases they are cumbersome. All the attempts to simplify beta spectrometers resulted in noticeable worsening of depth resolution for the DS EMS method making the measurements non precise. There is currently an obvious need in a highly-effective portable easily controlled beta spectrometer. While developing such portable beta spectrometer, it is more promising to use as basis a simpler spectrometer, which has ratio of sample size to spectrometer size of about five times. The paper presents an equal-arm version of a highly-effective portable beta spectrometer with transverse heterogeneous sector magnetic field that assures double focusing. The spectrometer is equipped with a large-area non-equipotential source (a sample under investigation) and a position-sensitive detector. This portable spectrometer meets all requirements for achievement of the DS EMS depth resolution close to the physical limit and demonstrates the following main characteristics: equilibrium orbit radius ρ 0 = 80 mm, instrumental energy resolution 0.6 % at solid angle 1 % of 4π steradian, area of non-equipotential source ∼ 80 mm 2 , registration by position-sensitive detector of ∼ 10 % of the energy interval. Highly-effective portable beta spectrometer assures obtaining Moessbauer data with depth resolution close to physical limit of the DS EMS method. So in measurements at conversion and Auger electrons with energies of about units of keV and above, the achieved

  2. Moessbauer high pressure and magnetic field studies of the superconductor FeSe

    Energy Technology Data Exchange (ETDEWEB)

    Ksenofontov, Vadim; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz (Germany); Wortmann, Gerhard [Department of Physics, University of Paderborn, Paderborn (Germany); Trojan, Ivan; Palasyuk, Taras; Medvedev, Sergey; Eremets, Michail [Max-Planck-Institute for Chemistry, Mainz (Germany); McQueen, Tyrel M.; Cava, Richard J. [Department of Chemistry, Princeton University, Princeton (United States)

    2010-07-01

    Superconducting FeSe has been investigated by Moessbauer spectroscopy applying high pressure and strong external magnetic fields. It was found that pressure-induced structural phase transition between tetragonal and hexagonal modifications is accompanied by increased distortion of local surrounding of Fe atoms. Appearance of the hexagonal phase above 7.2 GPa is accompanied by degradation of superconducting properties of FeSe. Low-temperature measurements demonstrated that the ground states in both orthorhombic and hexagonal phases of FeSe are nonmagnetic. Moessbauer measurements in the external magnetic field below transition to the superconducting state revealed zero electron spin density on Fe atoms. Interpretation of Moessbauer spectra of FeSe in the Shubnikov phase is discussed.

  3. Moessbauer studies on ancient pottery from a neolithic site in Tung Wan, Hong Kong

    International Nuclear Information System (INIS)

    Zheng Yufang; Tang Chung

    1994-01-01

    Twelve ceramic sherds unearthed from different archaeological layers at a neolithic site in Tung Wan, Hong Kong, were studied by means of X-ray diffraction (XRD) and Moessbauer spectroscopy. The results show that the firing techniques used for ancient pottery wares at different layers were very different. For the oldest sherds (4000-3000 B.C.) from layer No. 4, the original firing temperature was low and craftmanship was inferior. For the sherds (1650-250 B.C.) from layer No. 2, the original firing temperature was above 1000 C. In addition, the results indicate that the ancient pottery wares from the ruins might not have been manufactured in the Tung Wan region. (orig.)

  4. Moessbauer studies of 57Fe substitution of Cu ions in superconducting oxides

    International Nuclear Information System (INIS)

    Saitovitch, E.B.

    1988-01-01

    Since the discovery of high-T c superconductivity in YBa 2 Cu 3 O 7 oxides several studies of metal ions substitutions were reported. The observed depression on T c without a systematic correlation with the charge and magnetic moment of Cu substituents claims for more detailed information about its local properties as can be revealed by 57 Fe Moessbauer spectroscopy. The results for different iron concentrations combined with modifications of the superconducting transition are discussed concerning the presence of magnetic moments on the Fe ions and the preferential occupation of Cu(1) sites, recently confirmed by neutron and electron diffraction experiments. The oxygen coordination for the different iron species are proposed on the basis of their dependence on Fe concentration, their behavior at high temperatures as well as the electron diffraction and electron microscopy measurements reported for Fe: YBa 2 Cu 3 O 7 samples. (author) [pt

  5. Moessbauer study of CO-precipitated Fischer-Tropsch iron catalysts

    International Nuclear Information System (INIS)

    Rao, K.R.P.M.; Huggins, F.E.; Mahajan, V.; Huffman, G.P.; Bukur, D.B.; Rao, V.U.S.

    1994-01-01

    Moessbauer spectroscopy studies of precipitated Fischer-Tropsch (FT) iron catalysts, viz. 100 Fe/5 Cu/4.2 K/x SiO 2 , where x = 0, 8, 16, 24, 25, 40, or 100, have shown that reduction of the oxide precursor in CO gives rise to χ-carbide Fe 5 C 2 whose amount decreases with an increase of SiO 2 content. The χ-carbide is converted into magnetite Fe 3 O 4 while catalyzing the FT synthesis reaction. A correlation between FT activity and the content of χ-carbide in the catalysts was found, which indicated that χ-carbide is active for FT synthesis reaction. (orig.)

  6. Visible light activated catalytic effect of iron containing soda-lime silicate glass characterized by 57Fe-Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Shiro Kubuki; Jun Iwanuma; Yusuke Takahashi; Kazuhiko Akiyama; Ernoe Kuzmann; Hungarian Academy of Sciences, Budapest; Tetsuaki Nishida

    2014-01-01

    A relationship between local structure and visible light activated catalytic effect of iron containing soda lime silicate glass with the composition of 15Na 2 O·15CaO·xFe 2 O 3 ·(70-x)SiO 2 , x = 5-50 mass %, abbreviated as NCFSx was investigated by means of 57 Fe-Moessbauer spectroscopy, X-ray diffractometry (XRD), small angle X-ray scattering (SAXS), electrospray ionization mass spectrometry (ESI-MS) and ultraviolet-visible light absorption spectroscopy (UV-Vis). Moessbauer spectra of NCFSx glass with 'x' being equal to or larger than 30 after isothermal annealing at 1,000 deg C for 100 min consisted of a paramagnetic doublet and a magnetic sextet. The former had isomer shift (δ) of 0.24 mm s -1 and quadrupole splitting (Δ) of 0.99 mm s -1 due to distorted Fe III O 4 tetrahedra, and the latter had δ of 0.36 mm s -1 and internal magnetic field (H int ) of 51.8 T due to hematite (α-Fe 2 O 3 ). The absorption area (A) of α-Fe 2 O 3 varied from 47.2 to 75.9, 93.1, 64.8 and 47.9 % with 'x' from 30 to 35, 40, 45 and 50, indicating that the amount of precipitated α-Fe 2 O 3 varied with the Fe 2 O 3 content of NCFSx glass. The precipitation of α-Fe 2 O 3 was also confirmed by XRD study of annealed NCFS glass with 'x' larger than 30. A relaxed sexted with δ, H int and Γ of 0.34 mm s -1 and 37.9 T and 1.32 mm s -1 was observed from the Moessbauer spectra of annealed NCFSx glass with 'x' of 45 and 50, implying that the precipitation of non-stoichiometric iron hydroxide oxide with the composition of Fe 1.833 (OH) 0.5 O 2.5 having the similar structure of α-Fe 2 O 3 and α-FeOOH. A remarkable decrease in the concentration of methylene blue (MB) from 10 to 0.0 μmol L -1 with the first-order rate constant (k) of 2.87 × 10 -2 h -1 was observed for 10-day leaching test using annealed NCFS50 glass under visible light irradiation. ESI-MS study indicated that existence of fragments with m/z value of 129, 117 and 207 etc. originating from MB having m/z of 284. This

  7. Moessbauer and XRD Comparative Study of Host Rock and Iron Rich Mineral Samples from Paz del Rio Iron Ore Mineral Mine in Colombia

    International Nuclear Information System (INIS)

    Fajardo, M.; Perez Alcazar, G. A.; Moreira, A. M.; Speziali, N. L.

    2004-01-01

    A comparative study between the host rock and the iron rich mineral samples from the Paz del Rio iron ore mineral mine in Colombia was performed using X-ray diffraction and Moessbauer spectroscopy. Diffraction results of the iron rich mineral sample show that goethite, hematite, quartz, kaolinite and siderite are the main phases, and that a small amount of illite is also present. By Moessbauer spectroscopy at room temperature (RT) the presence of all the above mentioned phases was detected except quartz as well as an additional presence of small amount of biotite. The goethite, which appears as four sextets with hyperfine fields of 33.5, 30.5, 27.5 and 18.5 T, respectively, is the majority phase. This result shows the different grades of formation of this oxyhydroxide. The Moessbauer spectrum of this sample at 80 K presents the same phases obtained at RT without any superparamagnetic effect. In this case the goethite appears as two sextets. Diffraction results of the host rock sample show a large amount of quartz and kaolinite and small amounts of illite and biotite, whereas by Moessbauer spectroscopy illite, kaolinite and biotite were detected.

  8. Applications of Moessbauer spectroscopy to the structural characterization of minerals and products of the country 's mining - metallurgical industry

    International Nuclear Information System (INIS)

    Herrera Palma, Victoria; Cruz Inclan, Carlos Manuel

    2016-01-01

    Since the seventies of the past century Moessbauer Spectroscopy (MS) has been systematically and successfully applied at CEADEN in the study and characterization of lateritic and other iron-rich ores, and different products of their industrial processing as well. Due to their high iron and chrome content these materials seemed to be attractive as raw material for the production of several enriched fractions in metallurgical applications. Such studies showed that the systematic application of MS combined with X- Ray Diffraction and other techniques like neutron Diffraction, Thermal and Calorimetric analysis and Optical and Electron Microscopies, has allowed a higher level of accuracy in the crystallographic characterization, and the phase composition and other specific properties assessment. As examples in this direction, in the present paper results of the study on two different iron-bearing materials are reported: a) magnetite of Mina Grande (in Santiago de Cuba), and b) Monitoring of a proposed process using concentration tables for chrome enrichment from tailings of the nickel plant 'Hector Ramos Latour' at Holguin, both areas located in the east of Cuba. It is evidenced that a right combination of 57 Fe Moessbauer Spectroscopy with other mentioned methods is nowadays the wisest and most efficient way for a thorough identification and characterization of iron-bearing mineral ores and products in mining and metallurgical industry. (Author)

  9. Evidences of the stability of magnetite in soil from Northeastern Argentina by Moessbauer spectroscopy and magnetization measurements

    International Nuclear Information System (INIS)

    Causevic, H.; Morras, H.; Mijovilovich, A.; Saragovi, C.

    2004-01-01

    In red soils from southern Brazil magnetite was reported to be pedogenically unstable, weathering to maghemite. However, in similar soils from northeastern Argentina magnetite was found in all size fractions. This finding motivates the mineralogical study of an Ultisol at different depths in order to understand the influence of anthropic and natural factors in the weathering of the magnetic minerals of these subtropical soils. The sand fraction of the B t22 horizon (105-155 cm depth) of a clayey red Ultisol from the subtropical forest of Misiones, Argentina, was studied by X-ray diffraction, saturation magnetization σ s , optical microscopy and Moessbauer spectroscopy. Saturation magnetization for the whole sand fraction (wsf), the non-magnetic sand fraction (nmsf) and the magnetic sand fraction (msf) are 10.79, 1.50 and 16.92 JT -1 kg -1 , respectively. Mainly quartz, ilmenite, Al-substituted hematite, goethite, maghemite and magnetite are found. Magnetite-maghemite contents are high, and magnetite is predominant in the msf. Results are compared with those from the upper B 1 horizon (10-35 cm depth) of the same soil in which a lower σ s(wsf) value, and higher values of σ s(msf) and of (σ s(msf) -σ s(wsf) ) were measured. These results confirm the stability of magnetite in this soil contrasting with other results on soils from neighbouring areas

  10. Moessbauer study of Mg-Ni(Fe) alloys processed as materials for solid state hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Palade, P.; Principi, G., E-mail: giovanni.principi@unipd.it; Sartori, S.; Maddalena, A. [Universita di Padova, Settore Materiali, DIM (Italy); Lo Russo, S. [Universita di Padova, Dipartimento di Fisica (Italy); Schinteie, G.; Kuncser, V.; Filoti, G. [National Institute for Materials Physics, Solid State Magnetism Department (Romania)

    2006-02-15

    Mg-Ni-Fe magnesium-rich intermetallic compounds were prepared following two distinct routes. A Mg{sub 88}Ni{sub 11}Fe{sub 1} sample (A) was prepared by melt spinning Mg-Ni-Fe pellets and then by high-energy ball milling for 6 h the obtained ribbons. A (MgH{sub 2}){sub 88}Ni{sub 11}Fe{sub 1} sample (B) was obtained by high-energy ball milling for 20 h a mixture of Ni, Fe and MgH{sub 2} powders in the due proportions. A SPEX8000 shaker mill with a 10:1 ball to powder ratio was used for milling in argon atmosphere. The samples were submitted to repeated hydrogen absorption/desorption cycles in a Sievert type gas-solid reaction controller at temperatures in the range 520 - 590 K and a maximum pressure of 2.5 MPa during absorption. The samples were analysed before and after the hydrogen absorption/desorption cycles by X-ray diffraction and Moessbauer spectroscopy. The results concerning the hydrogen storage properties of the studied compounds are discussed in connection with the micro-structural characteristics found by means of the used analytical techniques. The improved kinetics of hydrogen desorption for sample A, in comparison to sample B, has been ascribed to the different behaviour of iron atoms in the two cases, as proved by Moessbauer spectroscopy. In fact, iron results homogeneously distributed in sample A, partly at the Mg{sub 2}Ni grain boundaries, with catalytic effect on the gas-solid reaction; in sample B, instead, iron is dispersed inside the hydride powder as metallic iron or superparamagnetic iron.

  11. Moessbauer effect technique in mineral science

    International Nuclear Information System (INIS)

    Raclavsky, K.; Egiazarov, B.G.

    1975-01-01

    A survey is presented of literature devoted to the application of the Moessbauer effect in practical work. Significant problems are pointed to of applying Moessbauer spectroscopy in specific fields. An extensive list of references is annexed. (L.O.)

  12. Moessbauer Study of Iron-Containing Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Marco, J. F.; Gancedo, J. R. [CSIC, Instituto de Quimica-Fisica ' Rocasolano' (Spain); Hernando, A.; Crespo, P.; Prados, C.; Gonzalez, J. M. [Instituto de Magnetismo Aplicado (Spain); Grobert, N.; Terrones, M.; Walton, D. R. M.; Kroto, H. W. [University of Sussex, Fullerene Science Centre, School of Chemistry, Physics and Environmental Science (United Kingdom)

    2002-03-15

    {sup 57}Fe transmission Moessbauer at temperatures between 18 and 298 K and magnetic measurements have been used to characterize Fe-filled carbon nanotubes which were prepared by pyrolisis of Ferrocene + C{sub 60} at atmospheric pressure under an Ar atmosphere at 1050{sup o}C. The Moessbauer data have shown that the Fe phases encapsulated within the carbon nanotubes are {alpha}-Fe, Fe{sub 3}C and {gamma}-Fe. The magnetic results are compatible with the Moessbauer data. Taken together the results allow us to propose a simple picture of the distribution of iron phases within the carbon nanotubes which would consist of an {alpha}-Fe core surrounded by an {gamma}-Fe shell, finally covered by an Fe{sub 3}C layer.

  13. Moessbauer study of phase transitions under high hydrostatic pressures. 1

    International Nuclear Information System (INIS)

    Kapitanov, E.V.; Yakovlev, E.N.

    1979-01-01

    Experimental results of the hydrostatic pressure influence on Moessbauer spectrum parameters are obtained over the pressure range including the area of structural phase transition. A linear increase of the Moessbauer effect probability (recoilless fraction) is accompanied by a linear decrease of the electron density at tin nuclei within the pressure range foregoing the phase transition. The electric resistance and the recoilless fraction of the new phase of Mg 2 Sn are lower, but the electron density at tin nuclei is greater than the initial phase ones. Hydrostatic conditions allow to fix clearly the diphasic transition area and to determine the influence of the pressure on the Moessbauer line position and on the recoilless fraction of the high pressure phase. The phase transition heat Q = 415 cal mol -1 is calculated using recoilless fractions of the high and low pressure phases at 25 kbar. The present results are qualitatively and quantitatively different from the results, obtained at nonhydrostatic conditions. (author)

  14. Moessbauer effect and electron paramagnetic resonance studies on yeast aconitase

    International Nuclear Information System (INIS)

    Suzuki, Takashi; Maeda, Yutaka; Sakai, Hiroshi; Fujimoto, Shigeru; Morita, Yuhei.

    1975-01-01

    The Moessbauer effect and electron paramagnetic resonance (EPR) of yeast aconitase [EC 4.2.1.3] purified from the cells of Candida lipolytica (ATCC 20114) were measured. Moessbauer spectra suggested that yeast acontitase mostly contained two high-spin Fe(III) ions in an antiferromagnetically coupled binuclear complex that resembled oxidized 2 Fe ferredoxins, together with a small amount of high-spin Fe(II). EPR spectra recorded no signal at 77 0 K, but showed a slightly asymmetric signal centered at g=2.0 at 4.2 0 K, presumably due to the small amount of Fe(II) Fe(III) pairs. (auth.)

  15. Moessbauer spectroscopic study of Fe{sup II}-doped sulphonated poly(ether-urethane)-styrene-acrylate copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, A. A. [Russian Academy of Sciences, Institute of Biochemistry and Physiology of Plants and Microorganisms (Russian Federation); Grigoryeva, O. P.; Fainleib, A. M. [National Academy of Sciences of Ukraine, Institute of Macromolecular Chemistry (Ukraine); Kuzmann, E., E-mail: kuzmann@ludens.elte.hu [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2013-04-15

    Thermoplastic linear ionomer based on sulphonated poly(ether-urethane)-styrene-acrylate copolymer, doped with natural Fe{sup 2 + }, was studied by Moessbauer spectroscopy at T = 78 and 290 K to monitor the chemical state of Fe species. The Fe{sup 2 + } added to aqueous suspension of the system was only partly oxidised in the course of polymer film preparation and drying in air. The oxidised part comprised a magnetic phase ({approx}19 % of total Fe both at T = 78 and 298 K) and a quadrupole doublet ({approx}40 %), while Fe{sup II} (over 40 %) stabilised in two types of microenvironments.

  16. SEM, optical, and Moessbauer studies of submicrometer chromite in Allende

    Science.gov (United States)

    Housley, R. M.

    1982-01-01

    New scanning electron and optical microscope results are presented showing that sub-micrometer chromite is abundant along healed cracks and grain boundaries in Allende chondrule olivine. Some wider healed cracks also contain pentlandite and euhedral Ni3Fe grains. Also reported are Moessbauer measurements on Allende HF-HCl residues confirming a high Fe(+++)/Fe(++) ratio.

  17. In-situ Moessbauer Spectroscopy with MIMOS II at Rio Tinto, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, I; Klingelhoefer, G; Wehrheim, S; Ebert, S; Panthoefer, M; Blumers, M; Schmanke, D; Maul, J; Schroeder, C [Institut fuer Anorganische und analytische Chemie, Johannes-Gutenberg-Universitaet Mainz, Staudinger Weg 9, 55128 Mainz (Germany); Rull, F, E-mail: fleischi@uni-mainz.d [Unidad Asociada UVA-CSIC, al Centro de AstrobiologIa, Universidad de Valladolid, 47006-Valladolid (Spain)

    2010-03-01

    The Rio Tinto, located in southwest Spain, exhibits a nearly constant, acidic pH-value along its course. Due to the formation of sulfate minerals, Rio Tinto is considered a potential analogue site for sulfate-rich regions on Mars, in particular at the landing site of the Mars Exploration Rover Opportunity, where the ferric sulfate mineral jarosite was identified with Opportunity's Moessbauer spectrometer. Primary and secondary mineralogy was investigated in situ with portable Raman and Moessbauer spectrometers at four different Rio Tinto sampling sites. The two techniques analyse different sample portions due to their specific field of view and sampling depth and provide complementary mineralogical information.

  18. In-situ Moessbauer Spectroscopy with MIMOS II at Rio Tinto, Spain

    International Nuclear Information System (INIS)

    Fleischer, I; Klingelhoefer, G; Wehrheim, S; Ebert, S; Panthoefer, M; Blumers, M; Schmanke, D; Maul, J; Schroeder, C; Rull, F

    2010-01-01

    The Rio Tinto, located in southwest Spain, exhibits a nearly constant, acidic pH-value along its course. Due to the formation of sulfate minerals, Rio Tinto is considered a potential analogue site for sulfate-rich regions on Mars, in particular at the landing site of the Mars Exploration Rover Opportunity, where the ferric sulfate mineral jarosite was identified with Opportunity's Moessbauer spectrometer. Primary and secondary mineralogy was investigated in situ with portable Raman and Moessbauer spectrometers at four different Rio Tinto sampling sites. The two techniques analyse different sample portions due to their specific field of view and sampling depth and provide complementary mineralogical information.

  19. Moessbauer and transport studies of amorphous and icosahedral Zr-Ni-Cu-Ag-Al alloys

    International Nuclear Information System (INIS)

    Stadnik, Z.M.; Rapp, O.; Srinivas, V.; Saida, J.; Inoue, A.

    2002-01-01

    The alloy Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 in the amorphous and icosahedral states, and the bulk amorphous alloy Zr 65 Al 7.5 Ni 10 Cu 7.5 Ag 10 , have been studied with 57 Fe Moessbauer spectroscopy, electrical resistance and magnetoresistance techniques. The average quadrupole splitting in both alloys decreases with temperature as T 3/2 . The average quadrupole splitting in the icosahedral alloy is the largest ever reported for a metallic system. The lattice vibrations of the Fe atoms in the amorphous and icosahedral alloys are well described by a simple Debye model, with the characteristic Moessbauer temperatures of 379(29) and 439(28) K, respectively. Amorphous alloys Zr 65 Al 7. )5Ni 10 Cu 7.5 Ag 10 and Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 have been found to be superconducting with the transition temperature, T c , of about 1.7 K. The magnitude of Tc and the critical field slope at Tc are in agreement with previous work on Zr-based amorphous superconductors, while the low-temperature normal state resistivity is larger than typical results for binary and ternary Zr-based alloys. The resistivity of icosahedral Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 is larger than that for the amorphous ribbon of the same composition, as inferred both from direct measurements on the ribbons and from the observed magnetoresistance. However the icosahedral sample is non-superconducting in the measurement range down to 1.5 K. The results for the resistivity and the superconducting T c both suggest a stronger electronic disorder in the icosahedral phase than in the amorphous phase. (author)

  20. Moessbauer effect and infrared study of some borate glass containing Mn and Fe oxides

    International Nuclear Information System (INIS)

    Gabr, M.

    2005-01-01

    Lithium borate glasses containing transition metals appeared now of very high technological and scientific interest. Therefore some lithium borate glasses containing mixed transition metal ions (manganese and iron) were investigated. The glass batches were melted at 1250 degree C for three hours and annealed at 350 degree C -over night- to obtain strain free glasses. Moessbauer Effect spectroscopy and Infrared analysis were employed to investigate the structural changes due to the change of their batches composition. Differential thermal analysis, magnetic susceptibility, density and molar volume measurements were also performed to study the effect of changing both manganese and iron oxides at the expense of boron oxide on these properties. Infrared analysis indicated the presence of different structural groups such as BO 3 , BO 4 , FeO 4 and MnO 6 as well as different vibrations indicated the presence of various bonds in the glass network. The values of the characteristic temperatures (T g , T c and T m ) showed gradual increase except those of the last sample where they showed a decrease. The mid sample showed the lowest stability value. It was found that the molar volume showed its highest value at R=0.33 [where R is the ratio of glass network modifier to the glass network former]. After that it showed gradual linear decrease. The magnetic susceptibility measurements showed approximately stable value between R=0.29 and 0.33, then it increased up to R=0.38, and after that, it decreased up to R= 0.43. The obtained magnetic susceptibility values indicated that all these glasses are paramagnetic. The obtained Moessbauer spectra and the calculated parameters confirmed that iron ions participated in the glass network as network former cations. It confirmed also that all glasses reflect paramagnetic character. The observed structural change were explained and correlated with the change of the measured physical properties

  1. Moessbauer study of austenite stability and impact fracture in Fe--6Ni steel

    International Nuclear Information System (INIS)

    Fultz, B.T.

    1978-06-01

    The two phase (α + γ) microstructure of a commercial cryogenic alloy steel was studied with regard to possible phase transformations induced by impact fracture. A backscatter Moessbauer spectrometer was constructed for measurements of atomic fractions of the two phases near specimen surfaces. Moessbauer spectra were collected from several types of unpolished and chemically polished surfaces of impact specimens to reveal (for the first time) the depth profile of the observed γ → α' transformation near fracture surfaces. It was found that the spatial extent of transformation could be monotonically related to the impact energy absorbed by the specimen. These results are interpreted in light of several models of phase stability and impact toughness. A general description of the Moessbauer effect and methods of spectral analysis is included. The method of linear perturbations in the hyperfine magnetic field is discussed with respect to its general usefulness in obtaining chemical information for Moessbauer spectra of the α phase. The procedure adopted for spectral analysis was chosen to provide an accurate phase analysis at the expense of chemical information. Both the Moessbauer equipment and analysis procedures were developed with the primary objective of providing a routine metallurgical phase analysis technique for low alloy steels

  2. Moessbauer analysis of recent ceramic finds from Chavin

    International Nuclear Information System (INIS)

    Wagner, U.; Wagner, F.E.; Stockklauser, A.; Salazar, R.; Riederer, J.; Kauffmann-Doig, F.

    1986-01-01

    A large number of ceramic sherds from Chavin, Peru, as well as recent clay samples from the same region have been studied by Moessbauer spectroscopy. The changes of the Moessbauer spectra of the clay were studied as a function of firing temperature and atmosphere. From a comparison of these data with those from the sherds one can make estimates of the precolumbian firing conditions. (Auth.)

  3. Characterization of clays found in soils of the indian territories in Rio Grande do Sul State by using the 57 Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Perez, C.A.S.; Gobbi, D.; Marcos, J.L.N.

    2004-01-01

    Clay samples collected from soils of indian territories of the middle plateau in Rio Grande do Sul were analyzed with the aim to obtain characterization data and technical parameters for their potential use as raw material for ceramic products. The mineralogical study in samples by using the X-ray diffraction technique demonstrated that the predominant clay mineral is kaolinite. Others minerals as quartz and rutile also are present in small amounts. Chemical analysis shows low percentages for oxides of Mg, Mn, K, Na, Ca, Cu and Zn (overall percentages smaller than 0.97%). The samples also were analyzed with the 57 Fe Moessbauer spectroscopy. The Moessbauer spectra at room temperature confirm the presence of the mineral kaolinite. At 77 K they reveal the existence of the minerals goethite and hematite as ultrafine magnetic particles in a superparamagnetic state. The physical tests performed in the samples show that these soils are very fine material and present appropriate granulometric characteristics and plasticity, which can be taken in advantage for the production of materials for construction or production of ornamental artifacts. (author)

  4. Moessbauer study of solute interactions with the lattice defect and grain boundary

    International Nuclear Information System (INIS)

    Ishida, Y.

    1979-10-01

    Moessbauer effect was used in the investigations of defect structures of Al- 57 Co alloys introduced by electron irradiation and grain boundary embrittlement in binary iron alloys containing sup(119m)Sn nuclei. The behaviour of tin during aging of Al-Cu-Sn alloys was examined by Moessbauer spectra during isothermal annealing of the samples at various temperatures. Similar investigations were conducted for polycrystalline and bicrystalline silver foils containing sup(119m)Sn sandwiched in the boundary. The binding state of tin atoms segregated at the grain boundary of fine grained iron and iron alloys provided the clues for the embrittlement of iron alloys. The inhibiting effect of Ti, V, and Mo can be explained by the usurpation of the electrons in the tin atoms to the 3d shell of iron. Moessbauer effect was extensively applied in studying the aging behaviour of aluminium alloys in quenching, ion-implantation and electron irradiation processes

  5. Magnetic and Moessbauer studies of amorphous Fe72-xYxHo8B20 alloys

    International Nuclear Information System (INIS)

    Krishnan, R.; Dumond, Y.; Ajan, A.; Shringi, S.N.; Prasad, S.

    1996-01-01

    We have carried out magnetic and Moessbauer studies of amorphous Fe 72-x Y x Ho 8 B 20 alloys. The Fe moment decreases with the addition of Y and a magnetic compensation occurs at 4 K for x=16. The temperature and field dependences of the magnetization have been interpreted using the mean field theory and Chudnovsky's model, respectively. These analyses yield some interesting parameters such as the random anisotropy, the exchange interactions J Fe-Fe , J Fe-Ho , etc. The Moessbauer studies show that the average hyperfine field decreases linearly with the addition of Y, in accordance with the decrease in the Fe moment. (orig.)

  6. Moessbauer study of Fe-Al disordered alloys near the critical concentration

    International Nuclear Information System (INIS)

    Bohorquez, A.; Tabares, J.A.; Perez Alcazar, G.A.; Gancedo, J.R.

    1994-01-01

    Disordered bcc Fe 1-q Al q alloys in the composition range 0.5≤q≤0.6 were studied by Moessbauer effect measurements. The Moessbauer spectra at 300 K of all the samples consist of two paramagnetic sites, one is a singlet and the other a doublet with quadrupole splitting. The results can be interpreted by considering that the sites of this disordered system are arranged near the configurations of the Fe and Al sites of the Fe-Al ordered system. (orig.)

  7. Moessbauer spectroscopy of the transformation of epsilon carbide during the tempering of Fe-C martensite - the existence of highly faulted cementite

    International Nuclear Information System (INIS)

    Genin, J.M.; Le Cear, G.; Simon, A.

    1975-01-01

    The results are reported of experimental verification of literature data on the transformation of epsilon carbide resulting from tempering Fe-C martensite at room temperature. Moessbauer spectroscopy was used in the experiments. The existence was ascertained of the considerable amount of faults previously found by electron diffraction. The possible cause of the faults are discussed. (L.O.)

  8. Moessbauer spectrometry applied to the study of laboratory samples made of iron gall ink

    International Nuclear Information System (INIS)

    Burgaud, C.; Rouchon, V.; Refait, P.; Wattiaux, A.

    2008-01-01

    Iron gall inks consist of a mixture of vitriol, gall nut extracts and gum arabic. The association of the iron(II) sulphate present in vitriols, and the carboxyphenolic acids present in gall nut extracts leads to the formation of dark coloured iron-based precipitates. In order to evaluate the percentage of iron used in the formation of these precipitates, transmission Moessbauer spectroscopy (MS) measurements were performed on laboratory made inks at room temperature. These were completed by X-ray diffraction (XRD), and Raman spectroscopy measurements. The samples consisted of several solutions of iron(II) sulphate, gallic acid and gum arabic. After evaporation, the residues were analysed. Up to eight different Moessbauer signatures were detected, most of them correlated to iron sulphates. The Moessbauer signature of the iron gall precipitate was also isolated. It is not distinctly defined and may overlap with the signatures of iron(III) hydroxy-sulphates, such as jarosite or copiapite. Raman spectrometry then proved to be a useful complementary technique for the identification of the precipitate. (orig.)

  9. Moessbauer spectroscopy of isotope separator implanted sup(119m)Sn in FCC metals

    International Nuclear Information System (INIS)

    Larsen, A.N.; Weyer, G.

    1979-01-01

    Radioactive sup(119m)Sn has been implanted in FCC metals by means of an isotope separator. Moessbauer spectra have been measured for the 24 keV transition of 119 Sn. Large substitutional fractions are found in all cases. A correlation for substitutional lattice sites between the measured isomer shifts of the impurity atoms and the force constants of the host lattices is discussed. Debye-Waller factors determined for substitutional Sn in the host lattices are found to be smaller than values calculated by a simple mass-defect model. For some host metals indications of an influence of radiation damage on the spectra are observed. Defect sites are assigned to Sn in aluminium and lead. Qualitative conclusions on the structures of these defects are drawn from the determined Moessbauer parameters. (author)

  10. Genesis of sandstone-type uranium deposits in the Sierra Pintada district, Mendoza, Argentina: a Moessbauer study

    International Nuclear Information System (INIS)

    Labenski, F.; Saragovi-Badler, C.

    1982-01-01

    The genesis of sandstone-type uranium deposits in the Cochico Group (Permo-Triassic) of the Sierra Pintada district, San Rafael, Mendoza, has been studied. This is the most important uranium district in Argentina. Uranium sources, uranium transport and precipitation are discussed. Uraninite and brannerite, the main uranium minerals, occur within the matrix of sandstone. Several phenomena can be deduced regarding the depositional environment. Where oxygen was available, precipitation of hydrated ferric oxides occurred; γFe 2 O 3 .nH 2 O varieties (identified by Moessbauer spectroscopy) precipitated in the upper levels of the aquifer, where CO 2 partial pressure was lower, giving reddish or reddish-brown beds. The CO 2 partial pressure also determines the distribution of biogenic agents such as bacteria. Bacteria thus find a more favourable environment for their development and action in upper levels of an aquifer. In the corresponding horizons local reduction occurred where UO 2 precipitated; therefore the highest uranium concentrations correspond to sandstone levels with reddish or reddish-brown pigment. These pigments have been identified by Moessbauer spectroscopy. (Auth.)

  11. Moessbauer study of C18N/Fe Langmuir-Blodgett layers

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, Erno [Institute of Chemistry, Eoetvoes Lorand University (Hungary); Telegdi, Judit [Institute of Nanochemistry and Catalysis, Chemical Research Center, HAS (Hungary); Nemeth, Zoltan, E-mail: hentes@chem.elte.hu; Vertes, Attila [Institute of Chemistry, Eoetvoes Lorand University (Hungary); Nyikos, Lajos [Institute of Nanochemistry and Catalysis, Chemical Research Center, HAS (Hungary)

    2012-03-15

    Langmuir-Blodgett (LB) films of octadecanoyl hydroxamic acid (C18N) complexed with Fe{sup 3 + } ions have been prepared at various subphase pH values. The LB films consisting of different number of layers were investigated by {sup 57}Fe conversion electron Moessbauer spectroscopy (CEM) at room temperature. The CEM detector contained a piece of {alpha}-iron, enriched with {sup 57}Fe, using as an internal standard. The Moessbauer pattern of the C18N/Fe LB films is a doublet with parameters {delta} = 0.35 mm/s and {Delta} = 0.74 mm/s. A gradual increase of the relative occurrence of the doublet compared to the sextet of the internal standard was observed with the increasing number of layers, indicating the nearly uniform distribution of Fe among the LB layers.

  12. Gamma-X-ray coincidence Moessbauer spectroscopic study of the aftereffects in sulfate hydrates

    International Nuclear Information System (INIS)

    Kobayashi, T.; Makita, T.; Fukumura, K.

    1990-01-01

    The anomalous charge states formed after the electron capture decay of 57 Co in FeSO 4 .H 2 O and FeSO 4 .7H 2 O are investigated using the conventional Moessbauer emission spectroscopy and a gamma-X ray coincidence method. This method is based on the idea that a Moessbauer spectrum observed with the coincidence technique only when K-X rays are emitted is reflected by isolated events with a reduced influence of the Auger-electron self-irradiation. The formation of the anomalous electronic and structural configuration is attributed to the self-radiolysis of the H 2 O and SO 4 2- ligands in the nearest and the second nearest coordination shells around the decaying atom. (orig.)

  13. Optimization of a conversion electron Moessbauer spectroscopy gas flow He/CH4 proportional counter

    International Nuclear Information System (INIS)

    Hanzel, D.; Griesbach, P.; Meisel, W.; Guetlich, P.

    1992-01-01

    A new detector for CEMS has been built and optimized with respect to the statistical quality of spectra obtained. The optimization has been performed by measuring Moessbauer and pulse height spectra at in- and off-resonance. Single channel analyzer settings were calculated by a new optimization routine. A comparison of different detector designs has been performed using the statistical utility rate of spectra obtained from a stainless steel foil. A procedure for determining optimal operating parameters for ICEMS gas flow proposed. (orig.)

  14. Maximum Entropy Method in Moessbauer Spectroscopy - a Problem of Magnetic Texture

    International Nuclear Information System (INIS)

    Satula, D.; Szymanski, K.; Dobrzynski, L.

    2011-01-01

    A reconstruction of the three dimensional distribution of the hyperfine magnetic field, isomer shift and texture parameter z from the Moessbauer spectra by the maximum entropy method is presented. The method was tested on the simulated spectrum consisting of two Gaussian hyperfine field distributions with different values of the texture parameters. It is shown that proper prior has to be chosen in order to arrive at the physically meaningful results. (authors)

  15. A closed cycle-cryostat for high-field Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Janoschka, A; Schuenemann, V; Svenconis, G

    2010-01-01

    A closed cycle-cryostat coupled to a Moessbauer spectrometer has been installed at the University of Kaiserslautern and is in full operation since march 2007. The setup is equipped with a low vibrating two-stage pulse tube cooler and has a cool down time of 48 h. The sample can be top loaded without the need to shut off the refrigerator. With the static helium exchange gas in the variable temperature insert the sample may be cooled down from room temperature to 50 K within several hours. Dynamic exchange gas with external supply of gaseous helium is used to cool the sample down to 2 K. The superconducting self-shielding split-coil generates a magnetic field of up to 5 Tesla and a stray field of ca. 60 mT at the outer cryostat walls. Moessbauer measurements can be performed in perpendicular or parallel field orientations. The sample holder and the Moessbauer drive are rigidly connected to the cryostat. In this way a line width of the two inner α-Fe lines of 0.32 mm/s has been currently achieved.

  16. Characterization of the Carancas-Puno meteorite by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ceron Loayza, Maria L., E-mail: malucelo@hotmail.com; Bravo Cabrejos, Jorge A. [Universidad Nacional Mayor de San Marcos, Laboratorio de Analisis de Suelos, Facultad de Ciencias Fisicas (Peru)

    2011-11-15

    We report the results of the study of a meteorite that impacted an inhabited zone on 15 September 2007 in the neighborhood of the town of Carancas, Puno Region, about 1,300 km south of Lima. The analysis carried out by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Moessbauer spectroscopy (at room temperature and at 4.2 K), reveal the presence in the meteorite sample of magnetic sites assigned to taenite (Fe,Ni) and troilite (Fe,S) phases, and of two paramagnetic doublets assigned to Fe{sup 2 + }, one associated with olivine and the other to pyroxene. In accord with these results, this meteorite is classified as a type IV chondrite meteorite.

  17. Positron annihilation and Moessbauer studies of neutron irradiated reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Brauer, G.; Matz, W.; Liszkay, L.; Molnar, B.

    1990-11-01

    Positron annihilation (lifetime, Doppler broadening) and Moessbauer studies on unirradiated, neutron irradiated and neutron irradiated plus annealed reactor pressure vessel steels (Soviet type 15Kh2NMFA) are presented. The role of microstructural properties and the formation of irradiation-induced precipitates is discussed. (orig.) [de

  18. Moessbauer spectroscopic study of polymer-bound heme complexes

    International Nuclear Information System (INIS)

    Tsuchida, Eishun; Nishide, Hiroyuki; Yokoyama, Hiroyuki; Inoue, Hidenari; Shirai, Tsuneo.

    1984-01-01

    Moessbauer spectra were measured on the heme complexes of poly(1-vinyl- and 1-vinyl-2-methylimidazole)(PVI and PMI) and heme derivatives with covalently bound imidazoleligand (IH) and 2-methylimidazole-ligand (MIH) embedded in poly(1-vinyl-2-pyrrolidone) film. Quadrupole splitting (ΔE sub(Q)) for the carbon monoxide adduct of PMI-heme indicated large electronic field gradient at the iron nucleus, probably due to steric hindrance of the polymer chain, and this behavior agreed with its low affinity with carbon monoxide. PMI-heme formed an oxygen adduct and its isomer shift and ΔE sub(Q) values were obtained. (author)

  19. Moessbauer studies of hemoglobin in high altitude polycythemia

    International Nuclear Information System (INIS)

    Zhang Xiufang; Shen Linming; Chen Songsen; Ao Zhaohui; Liu Yuanyuan; Gao Naifei; Zheng Yuanming; Shong Liangquan

    1990-01-01

    The Moessbauer spectra have been measured in erythrocytes from normal adults and the patients with high altitude polycythemia (HAPC). The results indicated that two subspectra ''a'' and ''b'', corresponding to oxy- and deoxyhemoglobin respectively, were present in all blood samples, and a third subspectrum ''c'' was found to exist in almost all samples from the patients. The parameters of the third subspectra ''c1'' in most samples from the patients were similar to those of carbon monoxyhemoglobin. The components were considered to be the denatured hemoglobin in RBCs (red blood cells). Together with clinical analysis, a possible mechanism of HAPC has been discussed. (orig.)

  20. Moessbauer and magnetic studies of parent material from argentine pampas soils

    International Nuclear Information System (INIS)

    Bidegain, J. C.; Bartel, A. A.; Sives, F. R.; Mercader, R. C.

    2007-01-01

    In order to establish a correlation between the different types of soils using hyperfine and magnetic parameters as climatic and environmental proxies, we have studied the differentiation of soil developed around 38.5 o south latitude, in the central Pampas of Argentina, by means of Moessbauer spectroscopy and environmental magnetism. The soils transect (climosequence) investigated stretches from the drier west (around 64 o W) to the more humid east (at around 59 o W) in the Buenos Aires Province, covering a distance of 600 km. The soils studied developed during recent Holocene geologic times in a landscape characterized by small relict plateaus, slopes and depressions, dunes and prairies. The parent material consists of eolian sandy silts overlying calcrete layers. The low mean annual precipitation in the western parts of the region gives rise to soils without B-horizons, which limits the agricultural use of land. The preliminary results show an increase of the paramagnetic Fe 3+ relative concentration from west to east in the soils investigated. Magnetite is probably mainly responsible for the observed enhancement in the susceptibility values. The magnetic response of the parent material is similar to that of the loess part of the previously investigated loess-paleosol sequences of the Argentine loess plateau.

  1. Moessbauer spectroscopy for characterizing biodegradation of magnetic nanoparticles in a living organism

    Energy Technology Data Exchange (ETDEWEB)

    Mischenko, Ilya Nikitich, E-mail: IlyaMischenko@rambler.ru; Chuev, Michail Alexandrovich; Cherepanov, Valeriy Mihailovich; Polikarpov, Michail Alexeevich [National Research Centre ' Kurchatov Institute' (Russian Federation)

    2012-03-15

    We have developed a model for describing nanoparticles magnetic dynamics. This allows us to fit self-consistently the wide set of the experimental data, particularly, the evolution of Moessbauer spectral shape with temperature and external magnetic field as well as the magnetization curves for nanoparticles injected into mice. Thus, we reliably evaluate changes in characteristics of the nanoparticles and their chemical transformation to ferritin-like forms in mouse's organs as a function of time after injection of nanoparticles. Actually, the approach allows one to quantitatively characterize biodegradation and biotransformation of magnetic particles in a body.

  2. Moessbauer and XRD study of pulse plated Fe-P and Fe-Ni thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Miko, Annamaria [Bay Zoltan Institute for Material Science (Hungary); Kuzmann, Erno, E-mail: kuzmann@para.chem.elte.hu [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Lakatos-Varsanyi, Magda [Bay Zoltan Institute for Material Science (Hungary); Kakay, Attila [Research Institute for Solid State Physics and Optics (Hungary); Nagy, Ferenc [Eoetvoes Lorand University, Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Department of Nuclear Chemistry (Hungary); Varga, Lajos Karoly [Research Institute for Solid State Physics and Optics (Hungary)

    2005-09-15

    {sup 57}Fe conversion electron Moessbauer spectroscopy, X-ray diffraction, electrochemical and magnetic measurements were used to study pulse electroplated Fe-P and Ni-Fe coatings. XRD and {sup 57}Fe CEMS measurements revealed the amorphous character of the novel pulse plated Fe-P alloys. CEM spectra indicated significant differences in the short range order and in the magnetic anisotropy between the Fe-P deposits pulse plated at medium long deposition time (t{sub on} = 2 ms), with short relaxation time (t{sub off} = 9 ms) and low current density (I{sub p} = 0.05 Acm{sup -2}) or at short deposition time (t{sub on} = 1 ms) with long relaxation time (t{sub off} = 250 ms) and high current density (I{sub p} = 1.0 Acm{sup -2}). The broad peaks centred around the fcc reflections in XRD of the pulse plated Ni-22 wt.% Fe deposit reflected a microcrystalline Ni-Fe alloy with a very fine, 5-8 nm, grain size. The CEM spectrum of the pulse plated Ni-22 wt.% Fe coating corresponded to a highly disordered solid solution alloy containing a minute amount of ferrihydrite. Extreme favourable soft magnetic properties were observed with these Ni-Fe and Fe-P pulse plated thin layers.

  3. Moessbauer and XRD study of pulse plated Fe-P and Fe-Ni thin layers

    International Nuclear Information System (INIS)

    Miko, Annamaria; Kuzmann, Erno; Lakatos-Varsanyi, Magda; Kakay, Attila; Nagy, Ferenc; Varga, Lajos Karoly

    2005-01-01

    57 Fe conversion electron Moessbauer spectroscopy, X-ray diffraction, electrochemical and magnetic measurements were used to study pulse electroplated Fe-P and Ni-Fe coatings. XRD and 57 Fe CEMS measurements revealed the amorphous character of the novel pulse plated Fe-P alloys. CEM spectra indicated significant differences in the short range order and in the magnetic anisotropy between the Fe-P deposits pulse plated at medium long deposition time (t on = 2 ms), with short relaxation time (t off = 9 ms) and low current density (I p = 0.05 Acm -2 ) or at short deposition time (t on = 1 ms) with long relaxation time (t off = 250 ms) and high current density (I p = 1.0 Acm -2 ). The broad peaks centred around the fcc reflections in XRD of the pulse plated Ni-22 wt.% Fe deposit reflected a microcrystalline Ni-Fe alloy with a very fine, 5-8 nm, grain size. The CEM spectrum of the pulse plated Ni-22 wt.% Fe coating corresponded to a highly disordered solid solution alloy containing a minute amount of ferrihydrite. Extreme favourable soft magnetic properties were observed with these Ni-Fe and Fe-P pulse plated thin layers.

  4. Electrochemical and conversion electron Moessbauer study of corrosion induced by acid rain

    International Nuclear Information System (INIS)

    Vertes, C.; Lakatos-Varsanyi, M.; Vertes, A.; Meisel, W.; Guetlich, P.

    1993-01-01

    The passivation of low carbon steel was studied in aqueous solution of 0.5M Na 2 SO 4 +0.001M NaHSO 3 (pH 3.5, 6.5 and 8.5) which can be considered as a model of acid rain. The used conversion electron Moessbauer spectroscopy (CEMS) with the complementary electrochemical investigations proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements showed much weaker pitting at pH 8.5. The compositions and thicknesses of the passive films formed during the electrochemical treatments are determined from the CEM spectra. Only γ-FeOOH was found on the surface of the samples at pH 6.5 and 8.5. Nevertheless, at pH 3.5 the sextet belonging to Fe 3 C appears in the spectra, and also FeSO 4 .H 2 O could be detected in low concentration. (orig.)

  5. Moessbauer studies of raw materials from Misti volcano of Arequipa (Peru) for its potential application in the ceramic field

    Energy Technology Data Exchange (ETDEWEB)

    Bustamante, Angel, E-mail: angelbd1@gmail.com [Universidad Nacional Mayor de San Marcos (Peru); Capel, Francisco; Barba, Flora, E-mail: flora@icv.csic.es; Callejas, Pio [Consejo Superior de investigaciones Cientificas (CSIC), Instituto de Ceramica y Vidrio (Spain); Guzman, Rivalino [Universidad Nacional de San Agustin de Arequipa (Peru); Trujillo, Alejandro [Universidad Nacional Mayor de San Marcos (Peru)

    2009-04-15

    We would like to introduce, the study of two different colour 'sillar' samples: white and pink, belonging to the Anashuayco quarry in the Arequipa Region (Peru). The X-ray diffraction (XRD) analysis indicates the presence of several mineralogical phases, such as feldpars and biotite for the both white and pink 'sillar' whereas cristobalite and quartz are detected only in the first sample and amorphous phase in the second one. In room temperature, Moessbauer spectroscopy, the presence of hematite ({alpha}-Fe{sub 2}O{sub 3}) was detected as the main phase for both samples, this was not detected in the XRD measurements. Moreover, corresponding doublets in the Moessbauer spectra indicate the presence of iron in the aluminium-silicate minerals. The rates Fe{sup 2+}/Fe{sup 3+} are 0.0752 and 0.0526 to the white and pink samples respectively. The minerals composing the white tuff form a heterogeneous aggregate of uniform aspect. Mining of these materials generates a great amount of waste in the form of lumps of varying size and which are raw materials studied in the present work for potential application in the ceramic field.

  6. Microstructure, magnetic and Moessbauer studies on spark-plasma sintered Sm-Co-Fe/Fe(Co) nanocomposite magnets

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N V Rama; Saravanan, P; Gopalan, R; Raja, M Manivel; Rao, D V Sreedhara; Chandrasekaran, V [Defence Metallurgical Research Laboratory, Hyderabad-500 058 (India); Sivaprahasam, D [International Advanced Research Centre for Powder Metallurgy and New Materials Hyderabad-500 005 (India); Ranganathan, R [Saha Institute of Nuclear Physics, Kolkata-700 064 (India)], E-mail: rg_gopy@yahoo.com

    2008-03-21

    Nanocomposite powders comprising Sm-Co-Fe intermetallic phases and Fe(Co) were synthesized by high-energy ball milling and were consolidated into bulk magnets by the spark-plasma sintering (SPS) technique. While the microstructure of the SPS samples was characterized by transmission electron microscopy (TEM), the solubility of Fe in different phases was investigated using Moessbauer spectroscopy. TEM studies revealed that the spark-plasma sintered sample has Sm(Co,Fe){sub 5} as a major phase with Sm{sub 2}(Co,Fe){sub 17}, Sm(Co,Fe){sub 2} and Fe(Co) as secondary phases. The size of the nanocrystalline grains of all these phases was found to be in the range 50-100 nm. The Moessbauer spectra of the as-milled powders exhibited two different subspectra: a sextet corresponding to the Fe phase and a broad sextet associated with the Fe(Co) phase; while that of the SPS sample showed four different subspectra: a sextet corresponding to Fe and other three sextets corresponding to the Fe(Co), Sm(Co,Fe){sub 5} and Sm{sub 2}(Co,Fe){sub 17} phases; these results are in accordance with the TEM observation. Recoil magnetization and reversible susceptibility measurements revealed magnetically single phase behaviour of the SPS magnets.

  7. Moessbauer and EPR studies on iron-dihydroxybenzoic acid and iron-itoic acid chelate complexes

    International Nuclear Information System (INIS)

    Bagyinka, Cs.; Horvath, L.I.; Keszthelyi, L.

    1984-01-01

    Low molecular weight iron-dihydroxybenzoic acid and iron-itoic acid complexes were investigated by Moessbauer and EPR spectroscopy. In strong acidic medium the iron is chelated in high spin ferrous form. By varying the pH of the medium a (S=2)Fesup(2+)→(S=5/2)Fesup(3+) transition was found with a midpoint pH value of 4. From the g'-tensor anisotropy it is concluded that the metal atom is coordinated by six oxygen atoms in rhombically distorted octahedral configuration. The biological significance of these structural data is briefly discussed. (author)

  8. /sup 57/Co Moessbauer study of the recovery process of electron-irradiated gold

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, I.; Nasu, S.; Fujita, F.E.

    1988-03-15

    The recovery process of Au--10-at. ppm-Co alloy after electron irradiation at 78 K was investigated by means of /sup 57/Co emission Moessbauer spectroscopy. Three satellite lines were observed and assigned to the small interstitial(I)--Co complexes, the micro-I-loops containing Co atoms and the divacancy-Co complexes, respectively. A fairly strong binding energy between the interstitial and Co atoms in small I-Co complexes, most probably larger than 0.2 eV, was deduced

  9. Electronic properties of iron impurity in hcp metals from Moessbauer studies

    International Nuclear Information System (INIS)

    Janot, C.; Delcroix, P.

    1975-01-01

    Moessbauer spectroscopy was used in quantitative investigating the electronic properties of iron impurities in hexagonal close-packed metals. Beryllium of the highest commercially obtainable purity containing about 300 ppm residual impurities was used as a host element. Experimental evidence is given for the existence of localized electronic states which have non-spherical distribution and obviously contribute especially to the electric field gradient. Iron impurity seems to retain the same electronic behaviour as long as the host hcp metal is a normal one (Mg, Cd, Zn), but the localized electronic states seem to disappear when the host is a transition hcp metal (Co, Ti, Sc, Zr, etc.). (Z.S.)

  10. Moessbauer study of miniature vessels from the Sican burial site of Huaca Loro

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, G., E-mail: gabriela.cervantes@pucp.pe [Pontificia Universidad Catolica del Peru (Peru); Shimada, I. [Southern Illinois University (United States); Haeusler, W.; Wagner, U.; Wagner, F. E. [Technische Universitaet Muenchen, Physik-Department E15 (Germany)

    2011-11-15

    Small handmade ceramic vessels are often found in large quantities in late pre-hispanic elite tombs on the north coast of Peru. These miniature vessels are of poor artistic and technologic qualities compared with other offerings found in tombs and have not received much attention. Our hypothesis is that these miniatures were made hastily by non-elite funeral attendants, which resulted in the observed formal and material variability. Here we report on the results of a systematic archaeological analysis of the shape and of archaeometric analyses by Moessbauer spectroscopy and XRD of the firing conditions of such vessels that were conducted to test the above hypothesis.

  11. Conversion electron Moessbauer and XPS study on the effect of polishing of a stainless steel sample

    International Nuclear Information System (INIS)

    Vertes, Cs.; Kuzmann, E.; Lakatos-Varsanyi, M.; Vertes, A.; Vass, G.; Romhanyi, K.

    1994-01-01

    Conversion electron Moessbauer spectroscopy (CEMS) and XPS has been used for the surface analysis of an 'X10CrNiTi 18/9 (DIN 1.7440)'-type stainless steel in order to determine the supposed structural and/or chemical changes in the surface layer caused by polishing. Both, CEMS and XPS results can be associated with the appearance of Fe nitride in the outer layer of steel samples after polishing, while no sing of nitrogen was detected in the bulk material. (author) 9 refs.; 3 figs.; 1 tab

  12. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  13. Mixed phase in cubic and hexagonal HoMn2111Cd PAC and 119Sn, 57Fe Moessbauer studies

    International Nuclear Information System (INIS)

    Cottenier, S.; Meersschaut, J.; Demuynck, S.; Swinnen, B.; Rots, M.

    1998-01-01

    Hyperfine parameters on 57 Fe, 119 Sn and 111 Cd substituted into the Mn sublattice were measured by Moessbauer and PAC spectroscopies. From these results it is tentatively concluded that C15 and C14 HoMn 2 are mixed-phase compounds. In C14 HoMn 2 there is no (or small) moment on the 2a site. (orig.)

  14. Contribution to 57Fe ion implanted garnet study by Moessbauer effect

    International Nuclear Information System (INIS)

    Kornilios, N.

    1986-11-01

    Due to because of their numerous physical properties, garnets are often used in new technologies. In order to improve their properties, ion implantation of inert gases has been proved to be a powerful technique to elaborate bubble memories. Recently it has been shown that high doses implanted ions, chemically reacting with the matrix could give interesting results. If the bulk is completely amorphized after implantation, further annealings can recrystallize it. In this study Y 3 F 5 O 12 , Y 3 Al 5 O 12 and Gd 3 Ga 5 O 12 single crystals were 100 keV implanted with 57 Fe ions at doses ranging between 10 16 and 10 17 ions cm -2 . The iron chemical states were determined thanks to Conversion Electron Moessbauer Spectroscopy (CEMS) and it was shown that the alloying elements of the matrix could influence the nature of the created phases. After thermal treatments the sample superficial layers were characterized using CEMS, grazing angle X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Rutherford Backscattering Spectroscopy (RBS). Different annealing stages were put forward: the oxidation of the implanted iron below 650 0 C and the garnet recrystallization around 850 0 C with some iron substitution in the garnet octahedral and tetraedral sites. The overstoechiometric iron forms particles of mixed oxides (FeAl) 2 O 3 , (FeGa) 2 O 3 or particles of pure Fe 2 O 3 oxide depending on the garnet. For the first time it is proved that after annealing around 1200-1300 0 C a complete rebuilding of the garnet matrix can induce for these oxide particles at room temperature a Morin transition [fr

  15. Moessbauer investigations of itmid

    International Nuclear Information System (INIS)

    Mrayed, Y.S.; Ellid, M.S.; Fallagh, F.A.

    1996-01-01

    A sample of itmid available commercially was obtained and investigated using 57 Fe Moessbauer spectroscopy, atomic absorption, X-ray fluorescence. The Moessbauer spectra showed the presence hematite (alpha-Fe 2 O 3 ), goethite (alpha-FeOOH), and a third phase which has a six-line spectrum with the following parameters : Isomer shift (gamma= 0.52 mm/s), magnetic field (H=290 kOe). After conducting a series of reduction and calcination to the itmid sample and with the aid of atomic absorption and X-ray fluorescence results the third phase was identified as the iron sulfide compound FeS. 3 figs., 3 tabs

  16. Advances in Moessbauer data analysis

    International Nuclear Information System (INIS)

    Souza, Paulo A. de

    1998-01-01

    The whole Moessbauer community generates a huge amount of data in several fields of human knowledge since the first publication of Rudolf Moessbauer. Interlaboratory measurements of the same substance may result in minor differences in the Moessbauer Parameters (MP) of isomer shift, quadrupole splitting and internal magnetic field. Therefore, a conventional data bank of published MP will be of limited help in identification of substances. Data bank search for exact information became incapable to differentiate the values of Moessbauer parameters within the experimental errors (e.g., IS = 0.22 mm/s from IS = 0.23 mm/s), but physically both values may be considered the same. An artificial neural network (ANN) is able to identify a substance and its crystalline structure from measured MP, and its slight variations do not represent an obstacle for the ANN identification. A barrier to the popularization of Moessbauer spectroscopy as an analytical technique is the absence of a full automated equipment, since the analysis of a Moessbauer spectrum normally is time-consuming and requires a specialist. In this work, the fitting process of a Moessbauer spectrum was completely automated through the use of genetic algorithms and fuzzy logic. Both software and hardware systems were implemented turning out to be a fully automated Moessbauer data analysis system. The developed system will be presented

  17. Site populations analysis of the Sm2(Co,Fe)17 alloys using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Nagamine, L.C.C.M.

    1990-01-01

    Moessbauer measurements were carried out at room temperature for Sm 2 (Co 1-x Fe x ) 17 alloys with x=0,1 to 0,6 and Sm 2 (Co 0.9-v Fe v Cu 0.08 Zr 0.02 ) 8.35 , with v=0.23 to 0.27. All samples were characterized by x-ray diffraction. They showed rhombohedral structure of Th 2 Zn 17 type (R 3-bar m), where Fe atoms occupy four crystallographic sites. All spectra showed magnetic splitting and a high complexity resulting from the superposition of four Fe sites. Hyperfine parameters and site populations were obtained by least-squares fitting of the spectra. (author)

  18. Moessbauer spectroscopy of iron (II) fluorosilicate-hexahydrate (temperature and pressure dependence)

    International Nuclear Information System (INIS)

    Volland, U.

    1979-01-01

    A pronounced temperature dependent asymmetry of the Moessbauer spectral lines with quadrupolar splitting is observed in the case of iron-fluoro-silicate-hexahydrate. For the increase in linewidth-difference at 225 K a thermal hysteresis is observed with a width of ΔT approx.= 2.5 K. As confirmed by X-ray analysis, at this temperature the crystal phase transition occurs simultaneously with the strong increase in linewidth, asymmetry. In slow electronic relaxation, which in the literature is porposed to be responsible for the different line-broadening characteristics, can be excluded on an experimental basis. Simple models are presented for an explanation of the findings, however, a physical interpretation of these models seems to be rather complicated. (orig./RB) [de

  19. Electronic and magnetic properties of rare earth-Sn3 compounds for 119Sn Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sanchez, J.P.; Friedt, J.M.; Shenoy, G.K.; Percheron, A.; Achard, J.C.

    1975-01-01

    The electronic and magnetic properties of RESn 3 compounds (RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Yb) have been investigated using the 23.8keV Moessbauer resonance of 119 Sn. The isomer shifts and quadrupole interactions are nearly the same in all compounds. The transferred magnetic fields and their orientation with respect to the principal electric field gradient axis at various Sn sites in the magnetically ordered state of RESn 3 (RE=Pr, Nd, Sm, Eu, Gd) have been utilized to get information about the magnetic structure. An evaluation of the transferred fields in PrSn 3 and NdSn 3 shows that the spin density at the Sn nucleus is nearly the same in both compounds [fr

  20. Moessbauer study of defects in molybdenum and chromium irradiated with ions

    International Nuclear Information System (INIS)

    Troyan, V.A.; Bogdanov, V.V.; Ivanyushkin, E.M.; Pen'kov, Yu.P.

    1980-01-01

    Effects of ion irradiation of monocrystalline molybdenum and polycrystalline chromium with Co-57 impurity were studied by Moessbauer effect. Molybdenum specimens were irradiated by He + ions at accelerators with 40 keV energy. Chromium specimens were irradiated by hydrogen ions with 1.2 MeV energy up to integral 2x10 17 -2x10 19 ion/cm 2 doses. It is shown, that defect introduction into the source matrix by irradiation results in change of gamma-resonance line form and effect value. The observed effects of defect influence on spectrum parameters are discussed. It is concluded, that study of Moessbauer spectra parameters of diluted Co-57 solutions in matrices of different metals permits to determine dynamics of movement of impurity atoms and defects in metals irradiated with ions [ru

  1. Self-contained high-pressure chambers for study on the Moessbauer effect at low temperatures

    International Nuclear Information System (INIS)

    Stepanov, G.N.

    1980-01-01

    Designs of two high-pressure chambers intended for studying the Moessbauer effect at low temperatures are described. The high-pressure chamber of the Bridgman anvil type is made of non magnetic materials and intended for operation at helium temperatures. The chamber employs a superconducting pressure gage. A sample and superconducting pressure gage are surrounded with a liquid medium of a high pressure at a room temperature. Measurements of the pressure were taken during heating the chamber in the vapours of liquid helium according to the known dependence of the lead superconducting transition temperature on pressure. The other high-pressure chamber of the piston-to-cylinder type can be used to study the Moessbauer effect at temperatures ranging from 4 to 300 K. Pressure in the chamber is measured by means of the superconducting pressure gage. The maximum pressure obtained in the chamber constitutes 25 kbar

  2. Development of a highly efficient conversion electron Moessbauer spectroscopy (CEMS) detector for low temperature (<20 K) measurements and tests on Fe / (Eu{sub x}Pb{sub 1-x})Te bilayers; Desenvolvimento de um detector de alta eficiencia para espectroscopia Moessbauer de eletrons de conversao (CEMS) a baixas temperaturas (<20K) e testes em bicamadas Fe / (Eu{sub x}Pb{sub 1-x})Te

    Energy Technology Data Exchange (ETDEWEB)

    Pombo, Carlos Jose da Silva Matos

    2006-07-01

    The {sup 57}Fe Moessbauer spectroscopy is a nuclear, non-destructive technique used for the investigation of structural, magnetic and hyperfine properties of several materials. It is a powerful tool in characterizing materials in physics, metallurgy, geology and biology field areas, especially magnetic materials, alloys and minerals containing Fe. Lately, the Conversion Electron Moessbauer Spectroscopy (CEMS) is widely used in making studies on ultra-thin magnetic films, as well as other nanostructured materials. In case of magnetic nanostructures, low temperature (LT) studies are especially important due to the possibility of dealing with superparamagnetic effects. In this work it was developed a CEMS measurement system for low temperatures (<20 K) based on a solid-state electron multiplier (Channeltron{sup R}) and an optical cryostat (Model SVT-400, Janis Research Co, USA), from which the project was originally conceived at the Applied Physics / Moessbauer spectroscopy Department from University of Duisburg-Essen, Germany. The LT-CEMS system was fully built, tested and successfully applied in a preliminary characterization of Fe/(Eu{sub x}Pb{sub 1-x})Te(111) bilayers with use of a 15 angstrom, {sup 57} Fe probe layer, with reasonable results at sample temperatures as low as 8 K. (author)

  3. Moessbauer spectroscopy and X-ray diffraction analyses of clayey samples used as ceramic sourcing materials, in Peru

    Energy Technology Data Exchange (ETDEWEB)

    Quille, Ruben, E-mail: quilleruben@gmail.com; Bustamante, Angel [San Marcos National University, Laboratory of Ceramics and Nanomaterials, Faculty of Physical Sciences (Peru); Palomino, Ybar [National University of San Cristobal de Huamanga, Experimental Center of Ceramics (Peru)

    2011-11-15

    The ceramic industry is an important area of economic activity in the Ayacucho Region, in particular in the District of Quinua. As a consequence, there is a huge demand for clay to produce ceramic pastes in that region. This paper reports on results concerning the mineralogical characterization of four clayey samples, which were collected MAA and SPQA from the area Pampa de La Quinua with geographic coordinates 13 Degree-Sign 02 Prime 49 Double-Prime S 74 Degree-Sign 08 Prime 03 Double-Prime W, CE1M and CE2M from the Quinua locality 13 Degree-Sign 03 Prime 07 Double-Prime S 74 Degree-Sign 08 Prime 31 Double-Prime W, both in the District of Quinua, Province of Huamanga, Ayacucho, Peru. The chemical and mineralogical characterization of these samples was carried out with powder X-ray diffraction detecting quartz, albite, montmorillonite, kaolinite and glauconite mineral phases, Moessbauer spectroscopy detected iron in kaolinite, glauconite and montmorillonite minerals. Chemical analysis was performed through scanning electron microscopy and energy dispersive X-ray spectroscopy. Data obtained from the combination of these techniques provided relevant information about the morphology, chemical composition, and the mineralogy of samples.

  4. Moessbauer effect study on mechanically alloyed amorphous Fe1-xTix alloys

    International Nuclear Information System (INIS)

    Chen Hong; Xu Zuxiong; Ma Ruzhang; Zhao Zhongtao; Ping Jueyun

    1994-01-01

    Amorphous Fe 1-x Ti x (x = 0.50, 0.60) powders were produced by mechanical alloying from pure elemental powders in a vibratory ball-mill. X-ray diffraction (XRD) and Moessbauer effect (ME) were used to study the progress of amorphization and the property of hydrogen absorption in Fe-Ti alloys. The amorphization process and the properties of the amorphous phase are discussed. (orig.)

  5. Moessbauer study of 57Fe isolated in NH3 and NH3/Xe matrices

    International Nuclear Information System (INIS)

    Saitovitch, E.M.B.; Litterst, F.J.; Micklitz, H.

    1981-01-01

    Moessbauer studies on 57 Fe isolated in solid ammonia and ammonia/xenon mixtures were perfomed at 4.2 K and 77 K. They show clearly that atomic iron reacts only with one ammonia molecule forming FeNH 3 which is stable in an ammonia matrix up to 77 K. In addition a compound is formed which is attributed to an iron (II) hexammine. (Author) [pt

  6. Moessbauer Study of Electrodeposited Fe/Fe-Oxide Multilayers

    International Nuclear Information System (INIS)

    Kuzmann, E.; Homonnay, Z.; Klencsar, Z.; Vertes, A.; Lakatos-Varsanyi, M.; Miko, A.; Varga, L.K.; Kalman, E.; Nagy, F.

    2005-01-01

    Iron has been deposited electrochemically by short current pulses in Na-saccharin containing FeII-chloride and sulphate solution electrolytes. Combined electrochemical techniques with initial pulse plating of iron nanolayer and its subsequent anodic oxidation under potential control have been used for production of Fe/Fe-oxide multilayers. 57Fe CEM spectra of pulse plated iron revealed the presence of a minor doublet attributed mainly to γ-FeOOH in addition to the dominant sextet of α-iron. In the case of anodically oxidized pulse plated iron and of samples after repeated deposition of anodically oxidized pulse plated iron an additional minor doublet, assigned to ferrous chloride, also appears in the Moessbauer spectra. A significant change in the magnetic anisotropy of α-iron was observed with the anodic oxidation. The thickness of the layers were estimated from the CEM spectrum data by a modified computer program of the Liljequist method. The coercive field and the power loss versus frequency data showed that the pulse plated iron cores are good inductive elements up to several kHz frequencies

  7. Moessbauer study of cobalt and iron in the cyanobacterium (blue green alga)

    International Nuclear Information System (INIS)

    Ambe, Shizuko

    1990-01-01

    Moessbauer emission and absorption studies have been performed on cobalt and iron in the cyanobacterium (blue-green alga). The Moessbauer spectrum of the cyanobacterium cultivated with 57 Co is decomposed into two doublets. The parameters of the major doublet are in good agreement with those of cyanocobalamin (vitamin B 12 ) labeled with 57 Co. The other minor doublet has parameters close to those of Fe(II) coordinated with six nitrogen atoms. These suggest that cobalt is used for the biosynthesis of vitamin B 12 or its analogs in the cyanobacterium. The spectra of the cyanobacterium grown with 57 Fe show that iron is in the high-spin trivalent state and possibly in the form of ferritin, iron storage protein. (orig.)

  8. Neptunium tetrabromide: a Moessbauer and magnetic susceptibility study below 200K

    International Nuclear Information System (INIS)

    Stevens, J.L.; Jones, E.R. Jr.; Stone, J.A.; Karraker, D.G.

    1974-01-01

    NpBr 4 was studied by 237 Np Moessbauer resonance from 4.2 to 20 0 K and by vibrating-sample magnetometer from 2.2 to 70.5 0 K. The magnetic susceptibility exhibits typical Curie-Weiss behavior about 20 0 K and displays a sharp peak at 12.5 +- 0.5 0 K indicating an antiferromagnetic transition. The Moessbauer spectrum at 4.2 0 K agrees with previous work by Stone and Pillinger [J.A. Stone and W.L. Pillinger, Sym. Faraday Soc., 1, 77(1967)]. At approximately 13 0 K, there is a small decline in H/sub eff/ with paramagnetic relaxation effects remaining at higher temperatures. (U.S.)

  9. Thermal treatment of the Fe78 Si9 B13 alloy and the analysis of it magnetic properties through Moessbauer spectroscopy and Positronium annihilation

    International Nuclear Information System (INIS)

    Lopez M, A.

    2005-01-01

    The present work is divided in five chapters. In the first one a general vision of the amorphous alloys is given from antecedents, structure, obtaining methods, properties and problems that at the moment, focusing us in a certain moment to the iron base alloys and the anomalous problem of hardness that it presents the alloy Fe 78 Si 9 B 13 like previously mention us. The second chapter tries on the basic theory of the techniques of Moessbauer spectroscopy and Positron Annihilation spectroscopy, used for the characterization of our alloy as well as the complementary technique of X-ray diffraction (XRD) to observe that the amorphous phase was even studying. The third chapter describes the experimental conditions that were used to study the alloy Fe 78 Si 9 B 13 in each one of their thermal treatments. In the fourth chapter the obtained results and their discussion are presented. In the fifth chapter the conclusions to which were arrived after analyzing the results are presented. (Author)

  10. A Moessbauer Spectral Study of the Hull Steel and Rusticles Recovered from the Titanic

    Energy Technology Data Exchange (ETDEWEB)

    Long, Gary J., E-mail: glong@umr.edu; Hautot, Dimitri [University of Missouri-Rolla, Department of Chemistry (United States); Grandjean, Fernande; Vandormael, D. [University of Liege, Institute of Physics, B5 (Belgium); Leighly, H. P. [University of Missouri-Rolla, Department of Metallurgical Engineering (United States)

    2004-09-15

    The recent recovery of steel from the Titanic has permitted a 295 K conversion electron Moessbauer spectral study of the Titanic hull plate steel oriented with the gamma-ray direction either perpendicular or parallel to the microstructural banding directions. The two spectra reveal virtually identical average orientations of the magnetization close to the plane of the plate. The hyperfine parameters are virtually identical to those of {alpha}-iron, a finding which agrees with the chemical analysis which reveals at most 0.21 wt% carbon corresponding to 3 wt% of cementite in pearlite. A 4.2 to 295 K transmission Moessbauer spectral study of the rusticles reveals small particles of geothite undergoing superparamagnetic relaxation with a blocking temperature of ca. 300 K. In addition approximately two percent of the Moessbauer spectral absorption area corresponds to a quadrupole doublet with hyperfine parameters typical of green rust. The identified iron containing components in therusticles agree with the powder X-ray diffraction results which reveal the predominant presence of small particles of poorly crystallized goethite and traces of quartz and green rust. An average size of 20{+-}5 nm for the goethite particles is obtained from both the average hyperfine field and the broadening of the X-ray diffraction peaks. The magnetic anisotropy constant of the goethite particles deduced from the hyperfine field and the particle size is 8x10{sup 3} J/m{sup 3}.

  11. Amorphous substances: contribution of Moessbauer spectrometry. Pt. 6. Studies of amorphous metallic alloys and amorphous semiconductors using Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Le Caer, G.; Dubois, J.M.

    1980-01-01

    The sensitivity of Moessbauer spectrometry to the immediate environment of the nucleus is both an advantage and a disadvantage, because all the hyperfine parameters can be a priori distributed. The information related to these distributions (example local chemical order) depends on the hypotheses necessary for calculating the spectra. These hypotheses do not however seriously affect information on the texture or magnetic structure obtainable from the line intensities. These hypotheses are presented together with their consequences, an illustration being given for the case of the 57 Fe isotope. Some typical applications are then given [fr

  12. Moessbauer spectroscopy of minerals. Pt. 3. Octahedral-site Fe2+ quadrupole splitting distributions in the phlogopite-annite series

    International Nuclear Information System (INIS)

    Rancourt, D.G.

    1994-01-01

    We develop the methodology of quadrupole splitting distribution (QSD) analysis by evaluating the influences of absorber thickness, absorber texture, and the asumed Lorentzian width on the extracted QSD. We then present the first study to describe the Moessbauer spectra of members of a mineral family in terms of QSDs. The Fe 2+ QSD and its characteristics (average QS, peak QS, skewness, and standard deviation) show gradual trends with changing Fe/(Fe+Mg) in a synthetic Al-deficient phlogopite-annite series. Al-deficient natural samples of phlogopite and annite show similar behaviour. The Fe 2+ QSDs can be interpreted as population distribuitions of local distortion environments (LDEs) and, as such, contain much information that will become more accessible as theoretical calculations linking particular LDEs to corresponding QS values are developed. (orig.)

  13. Research by Moessbauer and infrared spectroscopy of films of polyacrylonitrile doped with FeCl2 and FeCl3

    International Nuclear Information System (INIS)

    Santos, Vadilson M. dos; Silva Filho, Eloi A. da; Nunes Filho, Evaristo

    2009-01-01

    The heating effect on films of polyacrylonitrile and doping of the ions Fe(II) and Fe (III) may reveal important aspects of the use of this polymer in the search for new materials. This paper was done the doping of the films of PAN with ions Fe(II) and Fe (III), with thermo heating is range of 60 a 90 deg C e de 90 a 170 deg C through the alkaline and acid hydrolysis of the CN groups used spectroscopy of FTIR and Moessbauer techniques to evaluate the structural changes results of doping process this polymer. The results showed that the FTIR spectral have a strong interaction of the ions Fe(II) and Fe (III) with PAN and confirmed by Moessbauer data. (author)

  14. Moessbauer study of the lattice dynamics of tin atoms in antimony

    International Nuclear Information System (INIS)

    Sitek, J.

    1975-01-01

    The Moessbauer effect probability f was investigated for tin impurity atoms in the SnSb solution (the impurity varied from 3 at% to 15 at%). The absolute value of the Moessbauer effect probability was determined from Moessbauer absorption spectra by the area method using a calibration absorber of a β-tin foil with known f. (Z.S.)

  15. The Latin American Moessbauer research community

    International Nuclear Information System (INIS)

    Stevens, J.G.

    1994-01-01

    Interest in Moessbauer spectroscopy among the Latin American countries has increased in the last five years. Two-thirds of the published research is coming from the Moessbauer research groups in Brazil. Other Latin American countries with active Moessbauer research include Argentina, Chile, Columbia, Cuba, Mexico, Peru, and Venezuela. In recent years, the area having the most interest has been the investigation of minerals and high temperature superconductors. (orig.)

  16. Moessbauer studies of Haltern 70 amphorae from Castro do Vieito, North of Portugal, and of amphora sherds from kilns in the Roman provinces Hispania Baetica and Lusitania

    Energy Technology Data Exchange (ETDEWEB)

    Costa, B. F. O., E-mail: benilde@ci.uc.pt [University of Coimbra, CEMDRX, Physics Department (Portugal); Silva, A. J. M. [Centro de Estudos Arqueologicos das Universidades de Coimbra e do Porto/CAM, Palacio de Sub-Ripas (Portugal); Wagner, F. E.; Wagner, U. [Technical University of Munich, Physics Department (Germany)

    2011-11-15

    Haltern 70 amphora sherds from Castro do Vieito and from kilns in the Roman provinces Baetica and Lusitania were studied by Moessbauer spectroscopy, EDX and XRD. An amphora whose handle was carefully studied must have been fired reducingly at a temperature of or above about 900 Degree-Sign C and cooled in oxidizing conditions in the end. Oxidation and hematite formation went hand in hand, and the amount of hematite formed depended sensitively of the speed of penetration of the oxygen and the cooling rate in the interior of the ceramic body.

  17. 57Fe Moessbauer study of amorphous and nanocrystalline Fe73.5Nb3Cu1Si13.5B9 after neutron irradiation

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Szasz, Z.; Vitazek, K.

    1994-01-01

    57 Fe Moessbauer spectroscopy is used to study neutron irradiation induced changes in the short-range order of Fe 73.5 Nb 3 Cu 1 Si 13.5 B 9 alloy. The samples are investigated in both amorphous and nanocrystalline states. Neutron irradiation leads to an increase of the standard deviation of a hyperfine field distribution (HFD), implying rearrangement of the atoms towards disordering. Simultaneously, changes in the average value of the hyperfine field and a net magnetic moment position occur as a consequence of a spin reorientation, atom mixing and microscopic stress centres which are introduced by neutron irradiation. (orig.)

  18. A Moessbauer spectroscopic study of corrosion related reactions in the iron-hydrogen fluoride-water-oxygen system

    International Nuclear Information System (INIS)

    Crouse, P.L.

    1989-03-01

    The results of a study of a number of corrosion related reactions in the Fe-HF-H 2 O-O2 system are presented. The primary techniques used were transmission and conversion electron Moessbauer spectroscopy. Conversion electron Moessbauer spectra were recorded at very low γ-photon glancing angles and at normal incidence. Depth profiles of surface layers were obtained by recording spectra at different glancing angles. The initial product which forms when an iron surface is exposed to the vapour of azeotropic hydrofluoric acid was identified as FeF 25 ·47H 2 O. With increasing film thickness, a product, identified as non-stoichiometric Fe 2 F 5 ·7H 2 O, was shown to occur. A thermodynamic analysis of the system is presented which shows FeF 3 ·3H 2 O to be the most stable compound under the experimental conditions used, and suggests a stepwise reaction sequence in which FeF 2 ·4H 2 O forms first, followed by Fe 2 F 5 ·7H 2 O and finally FeF 3 ·3H 2 O. Results obtained in a gravimetric study reveal the rate of reaction of metallic iron with the azeotropic vapour to be controlled by the rate of diffusion of the gaseous species through the product layer. In the case of the reactions with the vapour of higher dilutions of aqueous HF, the chemical reaction between the iron substrate and the gaseous species is rate controlling. 86 refs., 61 figs., 14 tabs

  19. Moessbauer effect in lattice dynamics. Experimental techniques and applications

    International Nuclear Information System (INIS)

    Chen, Yi-Long; Yang, De-Ping

    2007-01-01

    This up-to-date review closes an important gap in the existing literature by providing a comprehensive description of the applications of Moessbauer effect in lattice dynamics, along with a collection of applications in metals, alloys, amorphous solids, molecular crystals, thin films, and nanocrystals. It is the first book to systematically compare Moessbauer spectroscopy using synchrotron radiation to conventional Moessbauer spectroscopy, discussing in detail its advantages and capabilities, backed by the latest theoretical developments and experimental examples. Intended as a self-contained volume that may be used as a complete reference or textbook, 'Moessbauer Effect in Lattice Dynamics' adopts new pedagogical approaches with several non-traditional and refreshing theoretical expositions, while all quantitative relations are derived with the necessary details so as to be easily followed by the reader. Two entire chapters are devoted to the study of the dynamics of impurity atoms in solids, while a thorough description of the Mannheim model as a theoretical method is presented and its predictions compared to experimental results. Finally, an in-depth analysis of absorption of Moessbauer radiation is presented, based on recent research by one of the authors, resulting in an exact expression of fractional absorption and a method to determine the optimal thickness of an absorber. Supplemented by elaborate appendices containing constants and parameters. (orig.)

  20. High temperature Moessbauer study of order-disorder transformation in iron-aluminum alloys

    International Nuclear Information System (INIS)

    Oki, Kensuke; Yamamura, Akihiko; Kudo, Kazunao; Eguchi, Tetsuo

    1979-01-01

    Ordering process of iron rich Fe-Al alloys has been investigated at elevated temperatures by mean of Moessbauer spectroscopy. The observed spectra are analyzed to obtain the temperature dependences of the internal field, isomer shift and line width, and the results are discussed in connection with the ordering process. The alloy with 24.7 at% Al exhibits spectra, which are characteristic of the superposition of a single-line spectrum and a six-line one, originating from the ordered paramagnetic B2 or DO 3 state and disordered ferromagnetic α, respectively, and the results confirm the coexistence of α phase with B2 or DO 3 . The isomer shift of the paramagnetic component of the spectra shows discontinuous changes at the temperatures of transformation α reversible B2 and B2 reversible DO 3 . (author)

  1. Moessbauer study of the behaviour of synthetic corrosion products of nuclear power plants

    International Nuclear Information System (INIS)

    Blesa, M.A.; Maroto, A.J.G.; Passaggio, S.I.; Labenski, F.; Saragovi-Badler, C.

    1978-01-01

    Iron oxides are the main components of the circulating particles carried by the fluid in the primary circuit of nuclear power stations. The oxidation state of iron is (II, III), as in Fe 3 O 4 , or (III), as in Fe 2 O 3 , depending upon the reducing or oxidizing condition of the medium. Moessbauer spectroscopy allows the characterization of different forms of iron oxides, as well as iron and other metal mixed oxides. Also with this technique it is possible to detect the gradual changes in the stoichiometry of the phases due to oxidation. From the results obtained, it is concluded that the change in the oxygen content of the coolant in nuclear power stations will rapidly reflect itself in changes in the stoichiometry of the magnetite-type solids and, if higher levels of oxygen or localized attacks take place, the structure of the particles will suffer more drastic changes to hematite in a short time. (author)

  2. A Moessbauer study of the germanium two-electron donor centers in PbSe

    International Nuclear Information System (INIS)

    Terukov, E.I.; Khuzhakulov, Eh.S.

    2005-01-01

    The 73 As( 73 Ge) Moessbauer emission spectroscopy is used for identification of neutral and ionized two-electron germanium centers in PbSe. It is shown that the charge state of antistructural defect 73 Ge, generating in the anion sublattice after 73 As radioactive decay, does not depend on the Fermi level position. In contrast to this, the 73 Ge center in the cation PbSe sublattice represents the electrically active substitution impurity. The emission spectra correspond to the neutral state of the ( 73 Ge 2+ ) donor center in n-type conductors and to the double ionized state of this ( 73 Ge 4+ ) center in p-type conductors [ru

  3. The Moessbauer effect data center: A report

    International Nuclear Information System (INIS)

    Stevens, J.G.

    1990-01-01

    The Moessbauer Effect Data Center is unique in its operation and the kind of information services that it provides. It is probably the only user-supported information center in the basic sciences. This has been primarily possible due to the broad support and encouragement the center receives from the international Moessbauer community. This report also discusses the demographics of the Moessbauer community: identifying such items as the most active areas of research in Moessbauer Spectroscopy, where is this research being done and who is doing it. Also, examined is where Moessbauer research investigations are being published. BITNET and other forms of electronic mail are being widely used in the scientific community. This is also the case in the Moessbauer community. Directories and list-servers are being established. (orig.)

  4. 57Fe Moessbauer analysis of chrysotile asbestos from various mining regions

    International Nuclear Information System (INIS)

    Nagy-Czako, I.; Vertes, A.; Dravcevic, Z.; Lahodny-Sarc, O.

    1981-01-01

    57 Fe Moessbauer spectroscopy has been used for studying the oxidation and coordination state of iron in chrysotile asbestos from various mining regions in Canada, Rhodesia, USSR and Yugoslavia. It has been found that both the Fe 2+ and Fe 3+ ions occupy only the octahedral positions in the chrysotile crystal structure and that the Fe 2+ /Fe 3+ ratio depends strongly on the mining region. Moessbauer spectra have shown that the samples contain also magnetite. (author)

  5. Moessbauer study of (Fe1-x Cu x )4N (0.05≤x≤0.15) films

    International Nuclear Information System (INIS)

    El Khiraoui, S.; Sajieddine, M.; Vergnat, M.; Bauer, Ph.; Mabrouki, M.

    2007-01-01

    In this work, we have prepared nitrogenated Fe 1- x Cu x alloys by reactive evaporation under a flow of nitrogen ions. After annealing, X-ray diffraction shows that we have synthesized the γ'-(Fe 1- x Cu x ) 4 N (0.05≤x≤0.15) compounds. The films were investigated by Moessbauer spectroscopy. The crystallographic structure and the respective positions of the Fe and Cu atoms in the compounds have been determined

  6. Magnetic and Moessbauer studies on GdCo3B2 and DyCo3B2

    International Nuclear Information System (INIS)

    Malik, S.K.; Umarji, A.M.; Shenoy, G.K.

    1984-10-01

    Magnetization and Moessbauer studies have been carried out on GdCo 3 B 2 and DyCo 3 B 2 . These compounds are magnetically ordered with Curie temperatures of 56 0 and 21 0 K respectively. The Co atoms are either nonmagnetic or carry a small moment in these compounds. The saturation moment of DyCo 3 B 2 at 5 0 K is smaller than the Dy 3+ free-ion value. From 161 Dy Moessbauer studies, the measured hyperfine magnetic field at the Dy site is also observed to be smaller than the free-ion value. 155 Gd Moessbauer measurements in GdCo 3 B 2 reveal the presence of large crystalline electric fields at the rare earth site. This causes the moment and the hyperfine field at the Dy site in DyCo 3 B 2 to be reduced from its free-ion value

  7. Autonomous System Design for Moessbauer Spectra Acquisition

    International Nuclear Information System (INIS)

    Morales, A. L.; Zuluaga, J.; Cely, A.; Tobon, J.

    2001-01-01

    An autonomous system for Moessbauer spectroscopy based in a microcontroller has been designed. A timer of the microcontroller was used to generate the control signal for the Moessbauer linear motor, and a counter for the spectra acquisition. Additionally, the system has its own memory for data storage and a serial port to transmit the data to a computer for its later processing and display

  8. Moessbauer effect studies of magnetic interactions in iron and dilute iron alloys

    International Nuclear Information System (INIS)

    Woude, F. van der; Schurer, P.J.; Sawatzky, G.A.

    1975-01-01

    A temperature-dependent Moessbauer study was conducted in FeX alloys, where X = Al, Si, Ti, V, Cr, Mn, Co, and Ni, aimed at solving the problem of 'what is localized and what is itinerant in iron ferromagnetism'. The experimental results are interpreted using a phenomenological model based on a modified Zener-Vonsovskij theory. Absorption spectra of FeX alloys were measured as a function of temperature. It was found that the 3d magnetic moments in iron were mainly localized while exchange coupling was provided by partly itinerant 3d electrons. (L.D.)

  9. Moessbauer study of magnetic transformation of Ni3Al-(57Co+57Fe) surface layer

    International Nuclear Information System (INIS)

    Dudas, J.; Zemcik, T.

    1975-01-01

    The results of the magnetic transformation study of the Ni 3 Al-( 57 Co+ 57 Fe) surface layer by the 57 Fe Moessbauer effect in dependence on the penetration depth of ( 57 Co+ 57 Fe) are presented. These results are discussed in terms of the magnetic polarization of the Co (and Fe) atoms and the appearance of the 'giant' magnetic moment. The critical concentration of Co+Fe impurities sufficient for transformation of the originally paramagnetic surface layer into ferromagnetic at room temperature was determined to be 1.03 at.'=.. (author)

  10. Development of CuxFe/Al2O3 catalysts for the hydrogenation of carbon monoxide guided by magnetic methods, Moessbauer and infrared spectroscopy

    International Nuclear Information System (INIS)

    Boellaard, E.; Geus, J.W.; Bruggen, J.M. van; Kraan, A.M. van der

    1993-01-01

    A copper-iron catalyst for the hydrogenation of carbon monoxide has been prepared using a supported stoichiometric cyanide complex. Conversion of the cyanide precursor to a metallic catalyst appeared to be a precious process. Copper and iron in the bimetallic particles easily separate by thermal treatment and upon exposure to carbon monoxide, as revealed from Moessbauer and infrared spectroscopy. During Fischer-Tropsch reaction the catalyst exhibits a rapid decline of activity. Magnetisation measurements on spent catalysts indicate that the deactivation is caused by a fast conversion of metallic iron to initially unstable carbides which transform ultimately to more stable carbides. (orig.)

  11. Moessbauer investigations of itmid

    Energy Technology Data Exchange (ETDEWEB)

    Mrayed, Y S; Ellid, M S; Fallagh, F A [Physics and material Science Department, Tajoura Nuclear Research Center, Tripoli, (Libyan Arab Jamahiriya)

    1997-12-31

    A sample of itmid available commercially was obtained and investigated using{sup 57} Fe Moessbauer spectroscopy, atomic absorption, X-ray fluorescence. The Moessbauer spectra showed the presence hematite (alpha-Fe{sub 2} O{sub 3}), goethite (alpha-FeOOH), and a third phase which has a six-line spectrum with the following parameters : Isomer shift (gamma= 0.52 mm/s), magnetic field (H=290 kOe). After conducting a series of reduction and calcination to the itmid sample and with the aid of atomic absorption and X-ray fluorescence results the third phase was identified as the iron sulfide compound FeS. 3 figs., 3 tabs.

  12. Crystallization of some amorphous metallic alloys studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Miglierini, M.; Lipka, J.; Valko, P.; Toth, I.

    1990-01-01

    The present work provides an analysis of crystallization processes in amorphous metallic alloys Fe 80 Si 4 Cr 1.8 B 14 and Fe 67 Co 18 B 14 Si 1 . Crystallization of the first sample started at the temperature of 648 K. The fully crystalline state was observed after annealing at 748 K. We identified four sextets. One corresponds to crystalline Fe 2 B and the three others to FeSi solid solution with 10 at.% of Si. Crystallization of Fe 67 Co 18 B 14 Si 1 started at the temperature of 623 K. We identified two crystalline phases. The first may have its origin as (Fe 1-x Co x ) 3 B, the second one may correspond to a Fe-Co solid solution with a different Co content. (orig.)

  13. Inelastic scattering in condensed matter with high intensity Moessbauer radiation

    International Nuclear Information System (INIS)

    Yelon, W.B.; Schupp, G.

    1993-02-01

    The QUEGS facility at MURR has produced a number of new results and demonstrated the range of potential applications of high resolution, high intensity Moessbauer scattering. This work has been carried out by both MU and Purdue researchers and includes published results on Na, W, pentadecane, polydimethylsiloxane and other systems, manuscripts submitted on alkali halides (Phys. Rev. B) and accurate Moessbauer lineshape measurements (Phys. Rev. C), and manuscripts in preparation on glycerol, NiAl and Moessbauer spectra obtained by modulating a scattering crystal. Recently, new collaborations have been initiated which will substantially enhance our efforts. These are with W. Steiner (Vienna), G. Coddens (Saclay), and R. D. Taylor (Los Alamos). Steiner is experienced with Fe-57 Moessbauer scattering, while Coddens specializes in quasielastic neutron scattering; both of these areas naturally complement our work. R. D. Taylor has pioneered Moessbauer spectroscopy from the time of its discovery and has already made important contributions to our study of lattice dynamics and superconductivity for lead alloyed with small quantities of tin. At the same time, a significant instrument upgrade is underway, funded in part by the DOE-URIP program

  14. Electron hopping and temperature dependent oxidation states of iron in ilvaite studied by Moessbauer effect

    International Nuclear Information System (INIS)

    Heilmann, I.U.; Staun Olsen, J.; Olsen, N.B.

    1977-01-01

    The Moessbauer spectrum of ilvaite was measured between 115 K and 898 K, and the energy dispersive X-ray powder pattern was measured between 300 K and 1123 K. Below 500 K the Moessbauer spectrum varies strongly with temperature while the X-ray spectrum remains unchanged. The results are interpreted by electron exchange between nearly identical Fe-sites in ilvaite. (Auth.)

  15. Magnetic properties of PrMn2-xFexGe2-57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Wang, J L; Campbell, S J; Cadogan, J M; Tegus, O; Studer, A J; Hofmann, M

    2006-01-01

    We have investigated the magnetic behaviour of PrMn 2-x Fe x Ge 2 compounds with x = 0.4, 0.6 and 0.8 over the temperature range 4.2-350 K using ac magnetic susceptibility, dc magnetization and 57 Fe Moessbauer effect spectroscopy, as well as neutron diffraction for the PrMn 1.2 Fe 0.8 Ge 2 compound. Replacement of Mn with Fe leads to contraction of the unit cell and a shortening of the Mn-Mn spacing, resulting in modification of the magnetic structure. PrMn 1.6 Fe 0.4 Ge 2 is an intralayer antiferromagnet at room temperature and ferromagnetic below T C inter ∼230 K with additional ferromagnetic ordering of the Pr sublattice detected below T C Pr ∼30 K. Re-entrant ferromagnetism has been observed in PrMn 1.4 Fe 0.6 Ge 2 with four magnetic transitions (T N intra ∼333 K, T C inter ∼168 K, T N inter ∼152 K and T C Pr ∼40 K). Moreover, it was found that T C inter and T C Pr increase with applied field while T N inter decreases. PrMn 1.2 Fe 0.8 Ge 2 is antiferromagnetic with T N intra ∼242 K and T N inter ∼154 K. The magnetic transition temperatures for all compounds are also marked by changes in the 57 Fe magnetic hyperfine field and the electric quadrupole interaction parameters. The 57 Fe transferred hyperfine field at 4.5 K in PrMn 1.6 Fe 0.4 Ge 2 and PrMn 1.4 Fe 0.6 Ge 2 is reduced (below the ordering temperature of the Pr sublattice) compared with that at 80 K (above T C Pr ), indicating that the transferred hyperfine field from Pr acts in the opposite direction to that from the Mn atoms. The neutron data for PrMn 1.2 Fe 0.8 Ge 2 demonstrate that an anisotropic thermal expansion occurs within the interplanar antiferromagnetic range

  16. 57Fe Moessbauer spectroscopic characterisation of a ferromanganese nodule from the Central Indian Ocean

    International Nuclear Information System (INIS)

    Dutta, R.K.; Chakravortty, V.

    1997-01-01

    The iron bearing phases present in a ferromanganese nodule from the Central Indian Ocean have been determined using 57 Fe Moessbauer spectroscopy. The Moessbauer results have been corroborated by XRD, IR and TG-DTA studies. The Moessbauer spectrum of a ferromanganese nodule shows a broad line width which indicates the presence of more than one iron bearing paramagnetic oxide or oxyhydroxide phases where iron is present as Fe 3+ . γ-FeOOH has been distinctly characterised as one of the iron bearing phases in the nodule. Other oxyhydroxide and oxide phases of iron in the nodule have been ruled out. A typical paramagnetic doublet persists even at very high temperature which has been proposed to be due to iron(III)phosphate. Formation of solid solution of Mn 2 O 3 -Fe 2 O 3 has been observed in the heat treated nodule at 1073 K, which has been characterised by the Moessbauer technique. (author)

  17. 161Dy Moessbauer spectroscopy of the intermetallic compounds DyNi2Si2, DyNi2Ge2 and DyAg2Si2

    International Nuclear Information System (INIS)

    Onodera, Hideya; Murata, Akifumi; Koizuka, Masaaki; Ohashi, Masayoshi; Yamaguchi, Yasuo

    1994-01-01

    161 Dy Moessbauer spectroscopic study has been performed on DyNi 2 Si 2 , DyNi 2 Ge 2 and DyAg 2 Si 2 in order to clarify microscopic properties of antiferromagnets with incommensurate and sinusoidally moment-modulated structure. The experiments were done using the standard 161 Tb Moessbauer sources prepared by neutron irradiation at the Japan Material Testing Reactor. The Moessbauer spectra of DyNi 2 Si 2 are analyzed satisfactorily by a single set of hyperfine parameters, and hence the sinusoidal moment-modulation is considered to be realized through a distribution of spin relaxation rate. The broadened spectra of DyNi 2 Ge 2 are fitted tentatively by three subspectra. It seems for DyNi 2 Ge 2 that the incommensurate arrangement of Dy moments differed in magnitude as well as the distribution of spin relaxation rate originates the moment modulation. The fact that the spectrum of DyAg 2 Si 2 at 3 K consists of two distinct subspectra ensures the complicated antiferromagnetic structure where two kinds of Dy moments differed in magnitude are arranged noncollinearly. (author)

  18. X-ray diffraction and Moessbauer studies on superparamagnetic nickel ferrite (NiFe{sub 2}O{sub 4}) obtained by the proteic sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, N.A.S. [Departamento de Engenharia Metalúrgica e de Materiais, Centro de Tecnologia, Campus do Pici, Universidade Federal do Ceará – UFC, 60455-760 Fortaleza, CE (Brazil); Utuni, V.H.S.; Silva, Y.C. [Departamento de Física, Universidade Federal do Ceará – UFC, Campus do Pici, 60440-970 Fortaleza, CE (Brazil); Kiyohara, P.K. [Instituto de Física, Universidade de São Paulo – USP, 05315-970 São Paulo, SP (Brazil); Vasconcelos, I.F. [Departamento de Engenharia Metalúrgica e de Materiais, Centro de Tecnologia, Campus do Pici, Universidade Federal do Ceará – UFC, 60455-760 Fortaleza, CE (Brazil); Miranda, M.A.R., E-mail: marcus.a.r.miranda@gmail.com [Departamento de Física, Universidade Federal do Ceará – UFC, Campus do Pici, 60440-970 Fortaleza, CE (Brazil); Sasaki, J.M. [Departamento de Física, Universidade Federal do Ceará – UFC, Campus do Pici, 60440-970 Fortaleza, CE (Brazil)

    2015-08-01

    Nickel ferrite (NiFe{sub 2}O{sub 4}) nanoparticles were synthesized by the proteic sol–gel method at synthesis temperature of 250 °C, 300 °C and 400 °C, with the objective of obtaining superparamagnetic nanoparticles. Thermogravimetric analysis (TGA) and temperature-programed oxidation (TPO) presented peaks around 290 °C indicating that nickel ferrite was forming at this temperature. X-ray powder diffraction (XRPD) confirmed that the polycrystalline sample was single phased NiFe{sub 2}O{sub 4} with space group Fd3m. Scherrer equation applied to the diffraction patterns and transmission electron microscopy (TEM) images showed that the size of the nanoparticles ranged from 9 nm to 13 nm. TEM images also revealed that the nanoparticles were agglomerated, which was supported by the low values of surface area provided by the Brunauer-Emmet-Teller (BET) method. Moessbauer spectroscopy presented spectra composed of a superposition of three components: a sextet, a doublet and a broad singlet pattern. The sample synthetized at 300 °C had the most pronounced doublet pattern characteristic of superparamagnetic nanoparticles. In conclusion, this method was partially successful in obtaining superparamagnetic nickel ferrite nanoparticles, in which the synthetized samples were a mixture of nanoparticles with blocking temperature above and below room temperature. Magnetization curves revealed a small hysteresis, supporting the Moessbauer results. The sample with the higher concentration of superparamagnetic nanoparticles being the one synthetized at 300 °C. - Highlights: • Superparamagnetic nickel ferrite nanoparticles were grown by the proteic sol–gel method. • The proteic sol–gel method provided superparamagnetic nickel ferrite nanoparticles with sizes in the range of 9–13 nm. • Nickel ferrite nanoparticles were prepared at temperatures as low as 250 °C. • The nickel ferrite nanoparticles were studied by x-ray diffraction and Moessbauer.

  19. Moessbauer Study of Serpentine Minerals in the Ultramafic Body of Tehuitzingo, Southern Mexico

    International Nuclear Information System (INIS)

    Gonzalez-Mancera, G.; Ortega-Gutierrez, F.; Nava, N. E.; Arriola, H. S.

    2003-01-01

    Serpentine 'polymorph' minerals (chrysotile, lizardite, and antigorite) are hydrous Mg-Fe silicates that commonly form serpentine rock (serpentinite) by hydration of olivine-pyroxene peridotites from the mantle of the Earth. During the complex geologic history of orogenic belts, the redox and hydration state of the mantle changes, and olivine and pyroxenes are replaced by serpentine group minerals during tectonic deformation and uplift. Unfortunately, modern microanalysis of minerals by electron probe does not distinguish the oxidation state of iron, and it has to be assumed or estimated by precise methods, such as Moessbauer spectrometry. The studied samples were collected in the Xayacatlan Formation of the Tehuitzingo area, State of Puebla, within the Paleozoic Acatlan Complex. The original mantle peridotite was completely converted to serpentinite, with secondary crystallization of Fe-Mg oxides, calcsilicates, and carbonates. The three serpentine 'polymorphs' were identified in the studied samples, although with a clear predominance of the high-temperature member antigorite, which was preliminary determined by optical petrography, X-ray diffraction, electron probe, and scanning electron microscopy. Microprobe total iron content in most specimens was +3 substitution at the tetrahedral site may also occur according to some Moessbauer studies. This paper studied the iron valence state and its position in serpentine minerals of the Tehuitzingo ultramafic body using Moessbauer techniques. The analyses in most samples detected one doublet, compatible with Fe +2 in octahedral coordination, but only two specimens displayed two doublets corresponding to Fe +2 and Fe +3 in octahedral coordination. Doublets corresponding to Fe +3 in tetrahedral sites were not found. The parameters obtained for all the Fe +2 doublets are similar (QS=2.76±0.08 mm/sec, and IS=1.12±0.01), whereas the ratio Fe +3 /Fe +2 (0-0.34) has a strong tendency for iron to be in a divalent state. This

  20. Deconvolution of Moessbauer spectra using Voigt functions

    International Nuclear Information System (INIS)

    Flores Ll, H.J.

    1990-08-01

    The form of the resonance line in Moessbauer spectroscopy is a form of Lorentzian line, but this form of line it enlarges due to several effects: finite thickness of the absorber, instrumental instability, diffusion of Co 57 in crystals and fluctuations in the environment of the emitting nucleus. To take into account this effects it has been used as form of line in Moessbauer spectroscopy the Voigt function that is the convolution of a Lorentzian and a Gaussian. (Author)

  1. Moessbauer studies on some Argentinian soil: mollisols from Bahia Blanca

    International Nuclear Information System (INIS)

    Saragovi, C.; Venegas, R.

    1994-01-01

    Clay fractions of a Mollisol sample as is, treated with ammonium oxalate (AO), with dithionite-citrate-bicarbonate (DCB) and with dithionite-ethilene-diamine- tetraacetic acid (D-EDTA) methods, were studied. Illite-montmorillonites together with hematites, goethites and maghemites, all of the Al-substituted and with a wide range of sizes, were identified. It is found that the AO attack extracts little iron, whereas the other two attacks extract the magnetic signal. Furthermore, the DCB attack facilitates the reduction of the Fe 3+ ions, while the D-EDTA method does not. Instead, this attack extracts more clay mineral Fe ions. A comparison with large grain soil samples is made. (orig.)

  2. On the electronic phase diagram of Ba{sub 1-x}K{sub x}(Fe{sub 1-y}Co{sub y}){sub 2}As{sub 2} and EuFe{sub 2}(As{sub 1-x}P{sub x}){sub 2} superconductors. A local probe study using Moessbauer spectroscopy and muon spin relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Goltz, Til

    2015-10-28

    In this thesis, I study the electronic and structural phase diagrams of the superconducting 122 iron pnictides systems Ba{sub 1-x}K{sub x}(Fe{sub 1-y}Co{sub y}){sub 2}As{sub 2} and EuFe{sub 2}(As{sub 1-x}P{sub x}){sub 2} by means of the local probe techniques {sup 57}Fe Moessbauer spectroscopy (MS) and muon spin relaxation (μSR). For both isovalent substitution strategies - Co/K for Fe/Ba and P for As, respectively - the antiferromagnetic Fe ordering and orthorhombic distortion of the parent compounds BaFe{sub 2}As{sub 2} and EuFe{sub 2}As{sub 2} are subsequently suppressed with increasing chemical substitution and superconductivity arises, once long-range and coherent Fe magnetic order is sufficiently but not entirely suppressed. For Ba{sub 1-x}K{sub x}(Fe{sub 1-y}Co{sub y}){sub 2}As{sub 2} in the charge compensated state (x/2 ∼ y), a remarkably similar suppression of both, the orthorhombic distortion and Fe magnetic ordering, as a function of increasing substitution is observed and a linear relationship between the structural and the magnetic order parameter is found. Superconductivity is evidenced at intermediate substitution with a maximum T{sub SC} of 15 K coexisting with static magnetic order on a microscopic length scale. The appearance of superconductivity within the antiferromagnetic state can by explained by the introduction of disorder due to nonmagnetic impurities to a system with a constant charge carrier density. Within this model, the experimental findings are compatible with the predicted s{sup ±} pairing symmetry. For EuFe{sub 2}(As{sub 1-x}P{sub x}){sub 2}, the results from {sup 57}Fe MS and ZF-μSR reveal an intriguing interplay of the local Eu{sup 2+} magnetic moments and the itinerant magnetic Fe moments due to the competing structures of the iron and europium magnetic subsystems. For the investigated single crystals with x = 0.19 and 0.28, {sup 57}Fe MS evidences the interplay of Fe and Eu magnetism by the observation of a transferred

  3. Two earth years of Moessbauer studies of the surface of Mars with MIMOS II

    International Nuclear Information System (INIS)

    Klingelhoefer, G.; Morris, R. V.; De Souza, P. A.; Rodionov, D.; Schroeder, C.

    2006-01-01

    The element iron plays a crucial role in the study of the evolution of matter from an interstellar cloud to the formation and evolution of the planets. In the Solar System iron is the most abundant metallic element. It occurs in at least three different oxidation states: Fe(0) (metallic iron), Fe(II) and Fe(III). Fe(IV) and Fe(VI) compounds are well known on Earth, and there is a possibility for their occurrence on Mars. In January 2004 the USA space agency NASA landed two rovers on the surface of Mars, both carrying the Mainz Moessbauer spectrometer MIMOS II. They performed for the first time in-situ measurements of the mineralogy of the Martian surface, at two different places on Mars, Meridiani Planum and Gusev crater, respectively, the landing sites of the Mars-Exploration-Rovers (MER) Opportunity and Spirit. After about two Earth years or one Martian year of operation the Moessbauer (MB) spectrometers on both rovers have acquired data from more than 150 targets (and more than thousand MB spectra) at each landing site. The scientific measurement objectives of the Moessbauer investigation are to obtain for rock, soil, and dust (1) the mineralogical identification of iron-bearing phases (e.g., oxides, silicates, sulfides, sulfates, and carbonates), (2) the quantitative measurement of the distribution of iron among these iron-bearing phases (e.g., the relative proportions of iron in olivine, pyroxenes, ilmenite and magnetite in a basalt), (3) the quantitative measurement of the distribution of iron among its oxidation states (e.g., Fe 2+ , Fe 3+ , and Fe 6+ ), and (4) the characterization of the size distribution of magnetic particles. Special geologic targets of the Moessbauer investigation are dust collected by the Athena magnets and interior rock and soil surfaces exposed by the Athena Rock Abrasion Tool and by trenching with rover wheels. The Moessbauer spectrometer on Opportunity at Meridiani Planum, identified eight Fe-bearing phases: jarosite (K,Na,H3O

  4. New improvements in the characterization of refractory gold in pyrites: an electron microprobe, Moessbauer spectrometry and ion microprobe study

    International Nuclear Information System (INIS)

    Marion, P.; Holliger, P.; Boiron, M.C.; Cathelineau, M.; Wagner, F.E.

    1991-01-01

    Studies of pyrites by Moessbauer spectroscopy have shown the presence of gold in a combined state probably inserted within the lattice. In order to enhance detection limits for in-situ quantitative gold analyses, new SIMS investigations have been made thanks to a Resistive Anode Encorder record of the ion emissions, which provides digital images or scans of any part of the analyzed volume. Quantitative analysis of gold have been carried out thanks to 2 MeV ion implantation of gold in reference sulfide crystals, and the bulk composition of a pyrite grain has been determined. Some strong enrichments in gold and arsenic at the crystal margin attest fluctuations in the fluid chemistry and may be interpreted as a final growth zone, which is similar to that observed on arsenopyrite crystals. This multidisciplinary approach constitutes a powerful tool for the investigation of the insertion and distribution of trace elements within crystals, especially gold in sulfides at low contents down to a few ppm. (author)

  5. Moessbauer Studies of Stannous Fluoride Reactivity with Synthetic Tooth Enamel - A Model for the Tooth Cavity Protection Actions of Novel Dentifrices

    International Nuclear Information System (INIS)

    Denes, Georges; Muntasar, Abdualhafeed; Kozak, Kathy M.; Baig, Arif A.; White, Donald J.

    2002-01-01

    SnF 2 is an important toothpaste ingredient, added for the provision of clinical efficacy for hard and soft tissue diseases and in breath protection. Synthetic calcium hydroxyapatite powders were exposed to liquid supernates (25 w/w% toothpaste water slurries, centrifuged) of Crest Gum Care (registered) (SnF 2 ) dentifrice. One-minute treatments were followed by 3x water washing, centrifugation and lyophilization. Post treatment, powders were analyzed by Moessbauer spectroscopy with 0.5-1 gram of treated apatite powder. Results show that tooth mineral stannous fluoride interactions include: (1) formation of surface reaction products with both Sn(II) and Sn(IV) oxidation states; (2) Sn-F binding on mineral surfaces with no evidence of SnO. The surface binding is, however, not pure Sn-F but contains contributions of other ligands, probably oxygens from surface phosphates or hydroxyl groups. Results also suggest that surface reacted stannous tin is oxidized with time, even when bound as a layer on the tooth surface. This study demonstrates for the first time the presence of Sn-F on tooth enamel post treatment and the contribution of passivation to long term stannous chemistry on tooth surfaces. The study also illustrates the practical applications of the Moessbauer technique.

  6. Conversion electron Moessbauer spectroscopic studies on the chemical states of surface layers of corroded tin plates and tin-coated iron plates

    International Nuclear Information System (INIS)

    Kato, Akinori; Endo, Kazutoyo; Sano, Hirotoshi

    1980-01-01

    By means of the conversion electron Moessbauer spectroscopy (CEMS), we studied surface layers of ''tin'' plates and tin-coated iron plates corroded by various acids. Transmission Moessbauer spectra and X-ray diffraction patterns were also measured. Metastannic acid was formed, when the ''tin'' plate was corroded by nitric acid solution. In corrosion by phosphoric acid solution, the X-ray diffractometry revealed the formation of tin(IV) pyrophosphate. In corrosion by various organic acid solutions, the formation of oxides was identified by the 119 Sn CEMS, but not by the X-ray diffractometry because of the too thin corrosion layer. In corrosion of tin-coated iron plates, maleic acid, malonic acid, formic acid, and oxalic acid were used. It was determined by CEMS that the corrosion products caused by these acids were tin(IV) oxides, although they could not be identified by the X-ray diffractometry. CEMS also confirmed that the surface of uncorroded tin-coated iron plate was already oxidized by air. Colorimetric determinations of Sn and Fe dissolved from tin-coated iron plates to various acid solutions confirmed that maleic acid had the strongest corrosion effect among the organic acids studied. (author)

  7. Design and Construction of an Autonomous Low-Cost Pulse Height Analyzer and a Single Channel Analyzer for Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Velasquez, A.A.; Trujillo, J.M.; Morales, A.L.; Tobon, J.E.; Gancedo, J.R.; Reyes, L.

    2005-01-01

    A multichannel analyzer (MCA) and a single channel-analyzer (SCA) for Moessbauer spectrometry application have been designed and built. Both systems include low-cost digital and analog components. A microcontroller manages, either in PHA or MCS mode, the data acquisition, data storage and setting of the pulse discriminator limits. The user can monitor the system from an external PC through the serial port with the RS232 communication protocol. A graphic interface made with the LabVIEW software allows the user to adjust digitally the lower and upper limits of the pulse discriminator, and to visualize as well as save the PHA spectra in a file. The system has been tested using a 57Co radioactive source and several iron compounds, yielding satisfactory results. The low cost of its design, construction and maintenance make this equipment an attractive choice when assembling a Moessbauer spectrometer

  8. Observation of changing of the internal conversion coefficient under Moessbauer effect at magnetic transition in Rh-Fe system

    International Nuclear Information System (INIS)

    Ruskov, T.

    1998-01-01

    The magnetic disorder-order transition in the Rh-Fe alloy is studied by conversion electron Moessbauer spectroscopy. The drastic increase of the area under the Moessbauer spectrum at the transition from the paramagnetic to the magnetic state could be explained by diminishing the internal conversion coefficient. Thus our experimental results directly confirm the theory of the collective effect in the system of radiating developed by Yukalov

  9. Biotites from tuffs located in Mendoza, Argentina, seen by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Saragovi, C.; Labenski de Kanter, F.; Kleiman, L.; Valentin, R.; Puglisi, C.

    1990-01-01

    Several natural biotite samples were studied by M.E., electron microprobe and XRD. The M.E. parameters allow to group them as oxybiotites, normal biotites, chloritized biotites and muscovitized biotites. Mechanisms of oxybiotite formation and processes undergone by the rocks are discussed. (orig.)

  10. Moessbauer spectroscopic study of corrosion products beneath primer coating containing anticorrosive pigments

    International Nuclear Information System (INIS)

    Kumar, A.V.R.; Nigam, R.K.

    1998-01-01

    The phase analysis of the rusts generated beneath the primer containing micaceous iron oxide (MIO) and micaceous iron oxide in combination with red lead (RL), zinc phosphate (ZP), basic lead silicochromate (BLSC) and zinc chromate (ZC) has been carried out by Moessbauer spectroscopy at room temperature. The rust beneath the coating obtained after immersion of the painted panel for six months in 3% NaCl, consists mainly of non-stoichiometric magnetite together with small fractions of γ-, α-FeOOH except in the case of panel painted with RL containing MIO showed only a central doublet indicating the formation of γ-FeOOH and SPM α-FeOOH. Non-stoichiometry of magnetite as calculated from the ratio of B/A sites of the peaks of magnetite in the spectrum has been found depending on the nature of anticorrosive pigment present in the primer coating. The order of non-stoichiometry has been found to be in order of ZC > BLSC > ZP > MIO. (author)

  11. Iron-57 and iridium-193 Moessbauer spectroscopic studies of supported iron-iridium catalysts

    International Nuclear Information System (INIS)

    Berry, F.J.; Jobson, S.

    1988-01-01

    57 Fe and 193 Ir Moessbauer spectroscopy shows that silica- and alumina-supported iron-iridium catalysts formed by calcination in air contain mixtures of small particle iron(III) oxide and iridium(IV) oxide. The iridium dioxide in both supported catalysts is reduced in hydrogen to metallic iridium. The α-Fe 2 O 3 in the silica supported materials is predominantly reduced in hydrogen to an iron-iridium alloy whilst in the alumina-supported catalyst the iron is stabilised by treatment in hydrogen as iron(II). Treatment of a hydrogen-reduced silica-supported iron catalyst in hydrogen and carbon monoxide is accompanied by the formation of iron carbides. Carbide formation is not observed when the iron-iridium catalysts are treated in similar atmospheres. The results from the bimetallic catalysts are discussed in terms of the hydrogenation of associatively adsorbed carbon monoxide and the selectivity of supported iron-iridium catalysts to methanol formation. (orig.)

  12. Nuclear gamma resonance absorption (Moessbauer) spectroscopy as an archaeometric technique to assess chemical states of iron in a Tupiguarani ceramic artifact from Corinto, Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Floresta, D.L.; Ardisson, J.D.; Fagundes, M.; Fabris, J.D.

    2013-01-01

    Archaeological ceramics of Tupiguarani Tradition are found in many parts throughout the Brazilian territory and have many similarities. Fragments of Tupiguarani pottery found in the archaeological site known as Beltrao, in the municipality of Corinto, state of Minas Gerais, were identified and collected by researchers of the LAEP/UFVJM, in Diamantina, also in Minas Gerais. A selected fragment of about 15 mm-thick, with a color gradation across the ceramic wall ranging from red, on one side, grayish in the middle and orange on the opposite side, was transversely cut and a series of subsamples of powdered materials were collected from different depths across the wall, in layer segments of ∼3 mm, from the orange side. These powdered subsamples were analyzed with X-ray fluorescence and diffraction spectroscopy and 57 Fe Moessbauer spectroscopy at room temperature (298 K) and at 80 K. According to the XRF results, the elementary composition does not clearly vary with the depth in the sample. The powder XRD analysis revealed the occurrence mainly of quartz and muscovite. Results of 57 Fe Moessbauer spectroscopy reveal that hematite is the magnetically ordered phase. An Fe 2+ component appears for the grayish subsample. According to these results, the red subsample seems to be the external part of the pottery, representing the side that had direct contact with fire used to burn the precursor clay in air for this primitive ceramics preparation. The grayish middle layer is probably due to burning clay mixed with some ashes containing residual carbon, under milder temperature than on the external . (author)

  13. Moessbauer investigation of iron uptake in wheat

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, K., E-mail: kkriszti@bolyai.elte.hu [Eoetvoes Lorand University, Laboratory of Nuclear Chemistry, Institute of Chemistry (Hungary); Kuzmann, E. [Hungarian Academy of Sciences, Laboratory of Nuclear Chemistry, Chemical Research Center (Hungary); Fodor, F.; Cseh, E. [Eoetvoes Lorand University, Department of Plant Physiology (Hungary); Homonnay, Z.; Vertes, A. [Eoetvoes Lorand University, Laboratory of Nuclear Chemistry, Institute of Chemistry (Hungary)

    2008-07-15

    Iron uptake and distribution in wheat roots were studied with {sup 57}Fe Moessbauer spectroscopy. Plants were grown both in iron sufficient and in iron deficient nutrient solutions. Moessbauer spectra of the frozen iron sufficient roots exhibited three iron(III) components with the typical average Moessbauer parameters of {delta} = 0.50 mm s{sup -1}, {Delta} = 0.43 mm s{sup -1}, {delta} = 0.50 mm s{sup -1}, {Delta} = 0.75 mm s{sup -1} and {delta} = 0.50 mm s{sup -1}, {Delta} = 1.20 mm s{sup -1} at 80 K. These doublets are very similar to those obtained earlier for cucumber [0], which allows us to suppose that iron is stored in a very similar way in different plants. No ferrous iron could be identified in any case, not even in the iron deficient roots, which confirms the mechanism proposed for iron uptake in the graminaceous plants.

  14. 57Fe Moessbauer and magnetic studies of ErFe12-xNbx

    International Nuclear Information System (INIS)

    Wang, J L; Campbell, S J; Cadogan, J M; Tegus, O; Edge, A V J

    2005-01-01

    The structural and magnetic properties of ErFe 12-x Nb x compounds (x 0.6, 0.7 and 0.8) have been investigated by x-ray diffraction, ac susceptibility and dc magnetization measurements and 57 Fe Moessbauer spectroscopy. Refinements of the x-ray diffraction patterns show that the Nb atoms preferentially occupy the 8i sites; this can be understood in the terms of enthalpy effects and differences in the metallic radii. The average Fe-Fe distance at the different sites is found to behave as d Fe-Fe (8i)> d Fe-Fe (8j)> d Fe-Fe (8f). The unit cell volume increases slightly with increasing Nb content, consistent with the larger radius of Nb compared with Fe. A spin reorientation from easy-axis at room temperature to easy-cone at low temperatures has been detected for all compounds. The spin reorientation temperatures T sr in ErFe 12-x Nb x compounds remain essentially unchanged (T sr ∼42-44 K) with increasing Nb concentration, whereas a significant decrease in T sr (T sr1 ∼236-204 K; T sr2 ∼154-94 K) is obtained in DyFe 12-x Nb x from x = 0.6 to 0.8. This can be understood by taking the different crystal-field terms responsible for the spin reorientation in the two systems into account. We find that the spin-reorientation process is particularly sensitive to the sixth-order term B 60 O 60 of the crystal field acting on the Er 3+ ion, due to its large and positive value of γ J . 57 Fe hyperfine interaction parameters and magnetic moments values have been determined for the 8i, 8j and 8f sites from the Moessbauer spectra. The weighted average 57 Fe hyperfine field values were found to follow a T 2 dependence; this suggests that a single-particle excitation mechanism is responsible for reduction of the 3d-sublattice magnetization with increasing temperature

  15. Magnetic and thermal Moessbauer effect scans: a new approach

    International Nuclear Information System (INIS)

    Pasquevich, G. A.; Zelis, P. Mendoza; Sanchez, F. H.; Fernandez van Raap, M. B.; Veiga, A.; Martinez, N.

    2006-01-01

    Moessbauer transmission recorded at fixed photon energies as a function of a given physical parameter such as temperature, external field, etc. (Moessbauer scan), is being developed as a useful quantitative tool, complementary of Moessbauer spectroscopy. Scans are performed at selected energies, suitable for the observation of a given physical property or process. It is shown that one of main advantages of this approach is the higher speed at which the external physical parameter can be swept, which allows the recording of quasi-continuous experimental response functions as well as the study of processes which occur too fast to be followed by Moessbauer spectroscopy. The applications presented here are the determination of the temperature dependence of the 57 Fe hyperfine field in FeSn 2 , the thermal evolution and nanocrystallization kinetics of amorphous Fe 73.5 Si 13.5 Cu 1 Nb 3 B 9 and the measurement of the dynamic response of Fe magnetic moments in nanocrystalline Fe 90 Zr 7 B 3 to an external ac field.

  16. Mixed hyperfine interaction in amorphous Fe-Zr sputtered films in external magnetic field - a 57Fe Moessbauer study

    International Nuclear Information System (INIS)

    Fries, S.M.; Crummenauer, J.; Wagner, H.-G.; Gonser, U.; Chien, C.L.

    1986-01-01

    Conventional 57 Fe-Moessbauer spectroscopy provides only information about the magnitude of the splitting QS in the case of electric quadrupole hyperfine interaction, but not on the sign of the main component of the electric field gradient (EFG) or the asymmetry parameter which are sensitive to the local environment of the 57 Fe nuclei. This kind of information is obtained by measurements in external magnetic fields. In the case of amorphous Fe-Zr sputtered films mixed hyperfine interaction leads to a clear change in the behaviour of the Zr-rich and the Fe-rich alloys, indicating the existence of magnetic clusters in the Fe-rich samples. (Auth.)

  17. Moessbauer studies of one representative hydromorphic soil of the coastal area of the Rio de La Plata

    Energy Technology Data Exchange (ETDEWEB)

    Guichon, B. A. [Universidad Nacional de La Plata, Instituto de Geomorfologia y Suelos (Argentina); Desimoni, J.; Mercader, R. C., E-mail: mercader@fisica.unlp.edu.ar [Universidad Nacional de La Plata, Departamento de Fisica, IFLP-CONICET, Facultad de Ciencias Exactas (Argentina); Imbellone, P. A. [Universidad Nacional de La Plata, Instituto de Geomorfologia y Suelos (Argentina)

    2010-01-15

    In the present work, we have applied Moessbauer spectroscopy as well as the traditional chemical analyses to assess the contents of different states of Fe in oxides and hydroxides in an Entisol soil from the Argentine coastal plain of the Rio de La Plata. Tentative assignments for the different Fe ion sites are proposed. Our findings show that the isomer shift and quadrupole splitting are sensitive to the changes detected in the Fe{sup 2+} contents of the soluble phase while others remain constant within the experimental uncertainties.

  18. Moessbauer study of nickel containing 0.5% iron between room temperature and the Curie point

    International Nuclear Information System (INIS)

    Longworth, G.; Cranshaw, T.E.

    1983-01-01

    The Moessbauer measurements of the temperature variation of the spectra for nickel containing 0.5% iron by Hirsch have been repeated for a similar sample. No evidence was found for the magnetic first order transition postulated by Hirsch. (orig.)

  19. Developments in Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Waard, H. de

    1992-01-01

    Some subjects will be discussed that have recently received special attention or for which particularly interesting results have been obtained. Significant progress has been made also in several other fields. Rather than to attempt to make a complete overview, attention will be focused on a few selected topics only. (orig.)

  20. Positron lifetime and Moessbauer study of Fe80-xNixB20 metallic glasses

    International Nuclear Information System (INIS)

    Baluch, S.; Miglierini, M.; Groene, R.; Sitek, J.

    1989-01-01

    In order to investigate the short-range order (SRO) of iron-rich Fe 80-x Ni x B 20 (x = 10, 20, 30, 40) metallic glasses positron lifetime and Moessbauer measurements were carried out. Positron lifetimes of samples and Moessbauer hyperfine structure data of neutron-irradiated samples as functions of nickel content are shown and discussed. Results give evidence that high Ni content stabilizes the structure and can be connected with a higher degree of SRO in metallic glasses

  1. Moessbauer diffraction study of the Neel phase transition in Fe3BO6 crystal

    International Nuclear Information System (INIS)

    Kovalenko, P.P.; Labushkin, V.G.; Sarkisov, Eh.R.; Tolpekin, I.G.

    1987-01-01

    Phase transitions in a 57 Fe 3 BO 6 monocrystal in the vicinity of the Neel point, T N =507.5 K were investigated by means of the Moessbauergraphy. For the first time the relaxation type of Moessbauer spectra was observed near the phase transition point. First in the Moessbauer diffraction spectrum of the crystal the simultaneous presence of a component resulted from magnetic ordering and a paramagnetic component was observed

  2. 57Fe Moessbauer spectroscopic study on surface products of thin iron plates exposed to ambient atmosphere as a means of environmental monitoring

    International Nuclear Information System (INIS)

    Matsuo, Motoyuki; Kobayashi, Takaaki

    1993-01-01

    Conversion electron and transmission Moessbauer spectroscopy were applied to the analysis of thin iron plates exposed to the ambient atmosphere. The degree of corrosion of the iron plates was classified into three categories according to the kind and thickness of rust evaluated by Moessbauer spectra. The severe corrosion took place in seaside and roadside areas. The medium corrosion was observed in urban areas, and the weak corrosion occurred in suburban and mountainous areas. This fact implies that the surface products of iron plates can successfully reflect the ambient atmosphere to which the plates were exposed. (orig.)

  3. 57Fe Moessbauer effect studies of magnetic ordering in Lasub(1-x) Srsub(x)CoO3

    International Nuclear Information System (INIS)

    Bhide, V.G.; Rajoria, D.S.

    1975-01-01

    A detailed investigation of the Lasub(1-x)Srsub(x)CoO 3 system was performed for the entire range of Sr concentrations using X-ray diffraction for structural studies, DTA for phase transition analysis, Moessbauer and magnetic susceptibility studies for magnetic properties, and electrical resistivity and Seebeck coefficient studies for electron transport properties. Among other interesting results, samples with x > 0.125 were found to show ferromagnetic ordering. (A.K.)

  4. Moessbauer study of the composition and corrosion behaviour of electrodeposited and cast brass containing 1-4 m% tin

    International Nuclear Information System (INIS)

    Vertes, A.; Suba, M.; Varsanyi-Lakatos, M.; Czako-Nagy, I.; Pchelnikov, A.P.; Losev, V.V.

    1982-01-01

    Moessbauer measurements on electrodeposited and cast brass containing 1-4 m% tin were carried out using conversion electron detector. It was found that the tin formed phases with copper but not with zinc. The identified phases were β, γ, epsilon and eta and their ratio depended on the tin concentration and on the preparation process of the brass. The corrosion behaviour of the samples was also studied. (author)

  5. Deconvolution of Moessbauer spectra using Voigt functions; Deconvolucion de espectros Moessbauer empleando funciones Voigt

    Energy Technology Data Exchange (ETDEWEB)

    Flores Ll, H J

    1990-08-15

    The form of the resonance line in Moessbauer spectroscopy is a form of Lorentzian line, but this form of line it enlarges due to several effects: finite thickness of the absorber, instrumental instability, diffusion of Co{sup 57} in crystals and fluctuations in the environment of the emitting nucleus. To take into account this effects it has been used as form of line in Moessbauer spectroscopy the Voigt function that is the convolution of a Lorentzian and a Gaussian. (Author)

  6. Thermal treatment of the Fe{sub 78} Si{sub 9} B{sub 13} alloy and the analysis of it magnetic properties through Moessbauer spectroscopy and Positronium annihilation; Tratamiento termico de la aleacion Fe{sub 78} Si{sub 9} B{sub 13} y el analisis de sus propiedades magneticas mediante Espectroscopia de Moessbauer y Aniquilacion de positronio

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A

    2005-07-01

    The present work is divided in five chapters. In the first one a general vision of the amorphous alloys is given from antecedents, structure, obtaining methods, properties and problems that at the moment, focusing us in a certain moment to the iron base alloys and the anomalous problem of hardness that it presents the alloy Fe{sub 78}Si{sub 9}B{sub 13} like previously mention us. The second chapter tries on the basic theory of the techniques of Moessbauer spectroscopy and Positron Annihilation spectroscopy, used for the characterization of our alloy as well as the complementary technique of X-ray diffraction (XRD) to observe that the amorphous phase was even studying. The third chapter describes the experimental conditions that were used to study the alloy Fe{sub 78}Si{sub 9}B{sub 13} in each one of their thermal treatments. In the fourth chapter the obtained results and their discussion are presented. In the fifth chapter the conclusions to which were arrived after analyzing the results are presented. (Author)

  7. Characterization of Zn-bearing chlorite by Moessbauer and infrared spectroscopy - occurrence associated to the Pb-Zn-Ag deposits of Canoas, PR, Brazil; Caracterizacao de clorita portadora de Zn por espectroscopia Moessbauer e espectroscopia infravermelho - uma ocorrencia associada ao deposito de Pb-Zn-Ag de Canoas, PR, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Imbernon, Rosely Aparecida Liguori [Universidade de Sao Paulo (EACH/USP), SP (Brazil). Escola de Artes, Ciencias e Humanidades; Blot, Alain [Institut de Recherche pour le Developpement (IRD), Paris (France); Pereira, Vitor Paulo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Geociencias; Franco, Daniel Ribeiro, E-mail: imbernon@usp.br, E-mail: brotalain@free.fr, E-mail: vitor.pereira@ufrgs.br, E-mail: drfranco@on.br [Observatorio Nacional do Brasil (COGE/ON), Rio de Janeiro, RJ (Brazil). Coordenacao de Geofisica

    2011-06-15

    In order to provide new insights on mineralogical aspects of geochemical mapping/natural processes related to the chlorite formation (e.g. crystallochemistry and mechanisms of formation of these materials, which has been applied in different studies of environmental profiles), we investigated chlorite samples associated to the Pb-Zn-Ag sulfide ore from Canoas 1 deposit (Vale do Ribeira, state of Parana, Brazil). By means of Moessbauer (MS) and infrared (IV) spectroscopy, we addressed some issues as those related to the chloritization processes, as well as how Zn would be incorporated into its crystalline structure. Results carried out by ME and IV spectroscopy clearly pointed out for a chlorite occurrence, which in fact incorporates Zn into its structure and also alters the structural patterns for this mineral. Moreover, ME data sets indicated the presence of Fe which is located only in octahedral sites, in trans-configuration, and the Zn emplacement by the chloritization process also occurs in the brucite layer. (author)

  8. Moessbauer study of LaFeAsO and F-doped superconductors in external magnetic fields

    International Nuclear Information System (INIS)

    Kitao, S; Kobayashi, Y; Higashitaniguchi, S; Kurokuzu, M; Saito, M; Seto, M; Mitsui, T; Kamihara, Y; Hirano, M; Hosono, H

    2010-01-01

    The iron-based F-doped superconductors LaFeAsO 1-x F x with a transition temperature of 24 K (for x = 0.07) and 26 K (x = 0.11) and its parent material LaFeAsO were studied using 57 Fe Moessbauer spectroscopy. Further investigation was carried out by applying external magnetic fields. F-doped superconductors showed a singlet pattern with no magnetic splitting throughout the temperature range from 4.2 to 298 K. On the other hand, magnetically-split spectra were observed in the parent LaFeAsO below the Neel temperature of about 140 K. The internal magnetic field reached 5.3 T at 4.2 K. The external magnetic fields up to 14 T were applied to the singlet phases, F-doped superconductors and the parent LaFeAsO above the Neel temperature. The induced magnetically-split spectra showed the internal magnetic fields with the comparable value to the applied fields. This fact confirmed that these singlet phases have the paramagnetic feature. The magnetic fields were also applied to the magnetically-ordered phase of LaFeAsO below the Neel temperature. The evolution of the spectra depending on the external magnetic fields was clearly explained by a model with two sublattice spins of the powdered antiferromagnet. This fact confirmed the magnetically-ordered phase is an antiferromagnet. The spin-flop field was also estimated by the model as about 26 T.

  9. Quantitative Moessbauer analysis

    International Nuclear Information System (INIS)

    Collins, R.L.

    1978-01-01

    The quantitative analysis of Moessbauer data, as in the measurement of Fe 3+ /Fe 2+ concentration, has not been possible because of the different mean square velocities (x 2 ) of Moessbauer nuclei at chemically different sites. A method is now described which, based on Moessbauer data at several temperatures, permits the comparison of absorption areas at (x 2 )=0. (Auth.)

  10. OSSM2008 Polish Moessbauer Community Meeting: Program, Abstracts and List of Participants

    International Nuclear Information System (INIS)

    2008-01-01

    The Polish Moessbauer Community Meeting - OSSM2008 has been organized by Polish scientists using the Moessbauer spectroscopy in their research. Main subjects of the meeting are investigations of modern materials electronic structure by means of Moessbauer effect (ME), using ME in biological test of tissue diseases and ME investigation of physical properties of different steels

  11. Characterization of mineral phases of agricultural soil samples of Colombian coffee using Moessbauer spectroscopy and X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Humberto Bustos, E-mail: hbustos@ut.edu.co; Lozano, Dagoberto Oyola; Martinez, Yebrayl Antonio Rojas; Pinilla, Marlene Rivera [Universidad del Tolima, Grupo Ciencia de Materiales y Tecnologia en Plasma (Colombia); Alcazar, German Antonio Perez [Universidad del Valle, Grupo Metalurgia Fisica y Teoria de las Transiciones de Fase (Colombia)

    2012-03-15

    Soil chemical analysis, X-ray diffraction (XRD) and Moessbauer spectrometry (MS) of {sup 57}Fe were used to characterize mineral phases of samples taken from the productive layer (horizon A) of agricultural coffee soil from Tolima (Colombia). Chemical analysis shows the chemical and textural parameters of samples from two different regions of Tolima, i.e., Ibague and Santa Isabel. By XRD phases like illite (I), andesine (A) and quartz (Q) in both samples were identified. The quantity of these phases is different for the two samples. The MS spectra taken at room temperature were adjusted by using five doublets, three of them associated to Fe{sup + 3} type sites and the other two to Fe{sup + 2} type sites. According to their isomer shift and quadrupole splitting the presence of phases like illite (detected by DRX), nontronite and biotite (not detected by XRD) can be postulated.

  12. Fe(II-III) Hydroxysalt Green Rusts; from Corrosion to Mineralogy and Abiotic to Biotic Reactions by Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Genin, J.-M. R.

    2004-01-01

    Fe(II)-Fe(III) hydroxysalts commonly called green rusts are layered double hydroxides of formula [Fe II (1-x) Fe III x (OH) 2 ] x+ .[(x/n)A n- .(m/n)H 2 O] x- constituted of brucite-like layers containing Fe cations in the centres of OH - octahedrons and interlayers, which anions and water molecules belong to. They play a key role in corrosion and environmental sciences as well as mineralogy since they are, on the one hand, intermediate products between Fe(II) and Fe(III) states and, on the other hand, can be the major iron-bearing mineral in hydromorphic gley soils. Their crystal structure, Moessbauer spectra, methods of synthesis, abiotic as well as biotic, and some applications are presented here.

  13. Grazing incidence synchrotron X-ray diffraction and Moessbauer spectroscopy analyses of plasma nitrided ASTM F138 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Danilo Olzon Dionysio de; Ardisson, Jose Domingos, E-mail: dolzon@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Edilaine Honorio [Studiecentrum voor Kernenergie (Belgium); Olzon-Dionysio, Maristela; Souza, Sylvio Dionysio de; Fabris, Jose Domingos [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil); Martinez, L.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: systematic investigation of samples of plasma-nitriding austenitic stainless steels ASTM F138 and AISI 316L is reported. The surface treatment of the steels through plasma-nitriding was used to improve further the hardness, wear and corrosion resistance of these stainless steels. The resulting layered crystallographic structure actually corresponds to several phases with close cell parameters, making their identification and quantification a real experimental challenge. The ASTM F138 and AISI 316L stainless steel disks were plasma nitrided for 4 h at 400 deg C in a 80% H{sub 2} -20% N2 atmosphere at 6 torr, using plasma current frequencies between 6 and 100 kHz. Data of Moessbauer (CEMS and CXMS) and grazing incidence synchrotron X-ray diffraction (XRD-SR) were systematically collected. The nitrided layer thickness were not in general influenced by the plasma frequency, except at 12 kHz, which produced a layer thickness of approximately 8.0 mm, being in average 40% thicker than for the other samples. CXMS and CEMS Moessbauer spectra for this 12 kHz-sample show a much more pronounced magnetic resonance lines than for the other samples. The Fe{sub 4}N phase presents a single magnetic hyperfine interaction; the other two (Fe{sub 2-3}N and the expanded austenite) present both paramagnetic and magnetic components, even though their hyperfine parameters may not be safely separated. We also present the results of XRD-SR that were probed at several depths. The data from these techniques may be consistently correlated and this leads to an improved model to explain the structure of the nitrided layers. (author)

  14. Moessbauer spectra studied of spin-wave excitation for amorphous alloys

    International Nuclear Information System (INIS)

    Huang Zhigao

    1992-01-01

    The average hyperfine fields of amorphous Fe 70 Co 20 Zr 10 , Fe 80 Co 10 Zr 10 and Fe 86 Co 4 -Zr 10 alloys at different temperature were measured by the Moessbauer technique. According to Bloch's T 3/2 relation, spin-wave excitations of above amorphous alloys were studied and their B 3/2 values were found to be 0.40 +- 0.02, 0.45 +- 0.02 and 0.88 +- 0.04, respectively. Comparing the B 3/2 values of crystals, a-Fe-(Co, Ni)-ME, a-Fe-(Cr, Mn, W)-ME and a-Fe-B or TM-Zr invar alloys, the obvious difference among them was observed. Above results can be explained well by the exchange coupling fluctuation and the disorder of spatial arrangement. In this work, the difference between the stiffness coefficients obtained from the inelastic neutron scattering and the magnetization measurements for amorphous Invar alloys was also explained

  15. Portable and Automatic Moessbauer Analysis

    International Nuclear Information System (INIS)

    Souza, P. A. de; Garg, V. K.; Klingelhoefer, G.; Gellert, R.; Guetlich, P.

    2002-01-01

    A portable Moessbauer spectrometer, developed for extraterrestrial applications, opens up new industrial applications of MBS. But for industrial applications, an available tool for fast data analysis is also required, and it should be easy to handle. The analysis of Moessbauer spectra and their parameters is a barrier for the popularity of this wide-applicable spectroscopic technique in industry. Based on experience, the analysis of a Moessbauer spectrum is time-consuming and requires the dedication of a specialist. However, the analysis of Moessbauer spectra, from the fitting to the identification of the sample phases, can be faster using by genetic algorithms, fuzzy logic and artificial neural networks. Industrial applications are very specific ones and the data analysis can be performed using these algorithms. In combination with an automatic analysis, the Moessbauer spectrometer can be used as a probe instrument which covers the main industrial needs for an on-line monitoring of its products, processes and case studies. Some of these real industrial applications will be discussed.

  16. Moessbauer study on the distribution of iron vacancies in iron sulfide Fe sub(1-x)S

    International Nuclear Information System (INIS)

    Igaki, Kenzo; Sato, Masaki; Shinohara, Takeshi.

    1982-01-01

    The distribution of iron vacancies in iron sulfide Fe sub(1-x)S with the controlled compositions was investigated by Moessbauer spectroscopy at room temperature. Moessbauer spectrum was composed of several component spectra. These component spectra were assigned to the iron atoms with different configurations of neighboring iron vacancies. Judging from the composition dependence of intensity of each component, iron vacancies are considered to lie in every second iron layer for specimens with x between 0.125 and 0.10. For specimens with x between 0.10 and 0.09, this arrangement is nearly kept in the sample quenched from a higher temperature than 473 K, but after annealing at a lower temperature than 473 K iron vacancies are considered to lie not only in every second iron layer but also in every third iron layer or in adjacent iron layers. The iron vacancy arrangement lying in every third iron layer or in adjacent iron layers tends to dominate for specimens with x below 0.09. (author)

  17. Study of Moessbauer effect on LiFe5-x Alx O8, LiFe 5-x Gax O8 and LiGa5-x Fex O8 systems

    International Nuclear Information System (INIS)

    Barthem, V.M.T.S.

    1982-01-01

    The measures obtained by Moessbauer spectroscopy from LiFe 5-x Ga x O 8 and LiFe 5-x Al x O 8 systems are presented. A comparative study of the influences of dopant diamagnetic ions on magnetic structures of lithium ferrite was performed. The LiGa 5-x Fe x O 8 systems were analysed based on the existing data from LiAl 5-x Fe x O 8 systems, otaining informations about the iron ion behaviour in both matrices. (M.C.K.) [pt

  18. 127I Moessbauer study of some oxygen bonded iodine(I) and iodine(III) complexes

    International Nuclear Information System (INIS)

    Bardhan, M.; Birchall, T.; Frampton, C.; Kapoor, P.

    1988-01-01

    127 I Moessbauer spectra have been recorded at 4.2 0 K for a series of oxygen bonded iodine(I) and iodine(III) complexes. The sign of the quadrupole coupling constant is dependant only on the primary arrangement of ligands about the central iodine nucleus whereas the magnitude and the asymmetry parameter are more sensitive to ligand electronegativity and type. (orig.)

  19. 61Ni Moessbauer study of the surface hyperfine magnetic field in nickel

    International Nuclear Information System (INIS)

    Stadnik, Z.M.; Stroink, G.; Griesbach, P.; Guetlich, P.; Kohara, T.

    1988-01-01

    61 Ni Moessbauer measurements have been performed at 4.2 K on spherical Ni particles with an average diameter of 100 and 30 A, covered with a protective layer of SiO. Their spectra contain a surface component with a significantly reduced hyperfine magnetic field as compared with the field in the bulk. This result confirms recent theoretical predictions. (orig.)

  20. Moessbauer studies of iron(III)-(indole-3-alkanoic acids) systems in frozen aqueous solutions

    International Nuclear Information System (INIS)

    Kovacs, K.; Kuzmann, E.; Homonnay, Z.; Szilagyi, P.A.; Vertes, A.; Kamnev, A.A.; Sharma, V.K.

    2005-01-01

    Moessbauer investigations of iron(III) salts in aqueous solutions in the presence of indole-3-alkanoic acid ligands are described. The measurements showed two parallel reactions between the ligands and ferric ions: a complex formation and a redox process. The oxidation process takes place in the ligands, and a part of Fe 3+ is reduced to Fe 2+ . (author)

  1. Iron minerals formed by dissimilatory iron-and sulfur reducing bacteria studied by Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Chistyakova, N. I.; Rusakov, V. S.; Nazarova, K. A.; Koksharov, Yu. A.; Zavarzina, D. G.; Greneche, J.-M.

    2008-01-01

    Zero-field and in-field Moessbauer investigations and electron paramagnetic resonance (EPR) measurements to follow the kinetics of the iron mineral formation by thermophilic dissimilatory anaerobic Fe(III)-reducing bacteria (strain Z-0001) and anaerobic alkaliphilic bacteria (strain Z-0531) were carried out.

  2. Moessbauer studies of magnetic Fe2O3/SiO2 nanocomposite

    International Nuclear Information System (INIS)

    Lancok, A.; Zaveta, K.; Savii, C.; Barcova, K.

    2006-01-01

    Fe 2 O 3 /SiO 2 magnetic nanocomposites rich in Fe 2 O 3 have been obtained by annealing at 1000 grad C the xerogel samples, prepared under various conditions. The target concentrations of iron oxide in inert matrix were 20% and 30%. As mesoporous matrices both silica and polyvinyl alcohol - silica hybrid ones were used. The xerogel nanocomposite samples were obtained in situ and by impregnation under ultrasonic activation. All obtained samples were annealed under moderate oxidation conditions (air) and inert atmosphere such as vacuum or nitrogen. Moessbauer spectra were obtained using a conventional Moessbauer spectrometer with a 57 Co/Rh source and constant acceleration. Velocity calibration was done using α-iron, and the Moessbauer parameters are given relative to this standard at room temperature. The Moessbauer spectra contained the sextets of ε-Fe 2 O 3 , hematite, and superparamagnetic component. The content of various phases in the samples depends on the conditions of preparation. In one of the samples also magnetite was present. The ranges of the ε-Fe 2 O 3 area of the samples are 39-76%. The hematite phase is only residual, after transformation due to heat treatment. (authors)

  3. Moessbauer experiments, ch. 1

    International Nuclear Information System (INIS)

    Maring, K.W.

    1977-01-01

    The magnetic properties of iron base alloys have been investigated as a function of the concentrations of the sp-elements Al, Si, Ga, Ge, As, Sn, and Sb. An extensive description of the Moessbauer Effect Spectroscopy (MES) technique is given. The results of MES experiments at room temperature for FeX alloys (X stands for one of the sp-elements) and impurity concentrations of 1, 3 and 5 a/o are presented. Through temperature dependant measurements the hyperfine fields H ((m,n)T) at iron nuclei in different surroundings are obtained. The change of the Curie temperature of the various dilute iron-base alloys, with respect to pure iron, as a function of the impurity concentration is investigated. Average magnetic hyperfine fields and isomer shifts measured at 119 Sn nuclei in Fe 119 Sn are discussed

  4. A Moessbauer spectroscopic study on the action of Ce in the catalyst for dehydrogenation of etylbenzene to styrene

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Keyu, E-mail: keyujiang@126.com [East China Normal University, Department of Physics (China); Fan Qin; Chen Tong; Miao Changxi [Shanghai Research Institute of Petrochemical Technology, SINOPEC (China); Zhao Zhenji; Yang Xielong [East China Normal University, Department of Physics (China)

    2012-03-15

    Two series of Fe-K catalysts for dehydrogenation of ethylbenzene to styrene were prepared with different amounts and different compounds of the additional element Ce. Moessbauer spectroscopy has been used to determine the Fe compound in the catalyst and to investigate the effect of Ce. The catalytic properties of the catalysts have also been measured. The results show that the element Ce in the catalyst is favorable to form the predecessor of the catalytic active phase, the compound KFe{sub 11}O{sub 17} and that the optimal percentage of CeO{sub 2} is 8%{approx}15% in the catalyst which is favorable to the formation of KFe{sub 11}O{sub 17} and to get better catalytic properties.

  5. Mixed phase in cubic and hexagonal HoMn{sub 2} {sup 111}Cd PAC and {sup 119}Sn, {sup 57}Fe Moessbauer studies

    Energy Technology Data Exchange (ETDEWEB)

    Cottenier, S.; Meersschaut, J.; Demuynck, S.; Swinnen, B.; Rots, M. [Leuven Univ. (Belgium). Inst. voor Kern- en Stralingsfysika; Krop, K.; Marzec, J.; Zukrowski, J.; Przewoznik, J.; Japa, E. [Dept. of Solid State Physics, Univ. of Mining and Metallurgy, Krakow (Poland)

    1998-01-01

    Hyperfine parameters on {sup 57}Fe, {sup 119}Sn and {sup 111}Cd substituted into the Mn sublattice were measured by Moessbauer and PAC spectroscopies. From these results it is tentatively concluded that C15 and C14 HoMn{sub 2} are mixed-phase compounds. In C14 HoMn{sub 2} there is no (or small) moment on the 2a site. (orig.) 6 refs.

  6. Comparative study of crystallized melt-spun iron-boron alloys by Moessbauer effect and resistivity measurements

    International Nuclear Information System (INIS)

    Arshad, M.; Siddique, M.; Anwar-ul-Islam, M.; Butt, N.M.; Ashfaq, A.; Shamim, A.

    1993-01-01

    Moessbauer study of two as-quenched, melt-spun iron-boron completely crystallized alloys, Fe/sub 72/01/B/sub 28/ and Fe/sub 88/01/B/sub 12/, indicates the presence of alpha-Fe, Fe/sub 2/B and Fe/sub 3/B. The percentage of these phases is different in the two alloys. Resistivity measurements show to phase transformation of Fe/sub 3/B and Fe/sub 2/B, respectively. (author)

  7. Moessbauer, electron paramagnetic resonance and magnetic susceptibility studies of photosensitive nitrile hydratase from Rhodococcus sp. N-771

    International Nuclear Information System (INIS)

    Nagamune, Teruyuki; Honda, Jun; Kobayashi, Yoshio; Sasabe, Hiroyuki; Endo, Isao; Ambe, Fumitoshi; Teratani, Yoshitaka; Hirata, Akira

    1992-01-01

    Moessbauer, magnetic susceptibility and electron paramagnetic resonance (EPR) studies of inactive and photoactivated NHase enzymes were performed to elucidate the electronic change of non-heme two-iron atom center of the enzyme by photoactivation. These spectroscopic investigations revealed that both the two iron atoms of the active NHase could be assigned to low-spin ferric state, and those of the inactive NHase could each be assigned to low-spin ferric and low-spin ferrous ones. From these results, it was concluded that one of the non-heme iron atoms is oxidized in the inactive NHase during photoactivation. (orig.)

  8. Comments on Moessbauer-effect studies on 2-MeV proton-irradiated Nb3Sn

    International Nuclear Information System (INIS)

    Cox, D.E.; Sweedler, A.R.

    1979-01-01

    In a recent paper, Herber and Kalish have presented 119 Sn Moessbauer data for Nb 3 Sn irradiated by 2-MeV protons which they interpret in terms of a statistical distribution of site defects rather than interchange of Nb and Sn atoms. Further analysis of these data leads to the conclusion that they are in fact quite consistent with the presence of a substantial amount of radiation-induced site-exchange disorder. This is in agreement with the findings of a number of recent diffraction studies

  9. NMR and Moessbauer studies of the amorphous system Fe79P/sub 21-x/B/sub x/

    International Nuclear Information System (INIS)

    Amamou, A.; Durand, J.

    1977-05-01

    Combined NMR, spin-echo and Moessbauer experiments have been performed to obtain hyperfine field distributions of the transition metal and metalloid elements in splat-cooled amorphous Fe 79 P 21 /sub -x/B/sub x/ alloys. These distributions are related to the local environments of the elements. The NMR signals are observed in the low frequency range 20-60 MHz and all the nuclei, i.e. Fe, P and B, may contribute to the spectral distribution. The resolution of the spectra into that due to Fe and (P + B) nuclei was made possible by using samples prepared with an Fe 56 isotope. The Fe distribution thus obtaned shows general agreement with the Moessbauer field distribution. From a careful analysis of the NMR data, the hyperfine field at the B nuclei in these amorphous alloys is found to range from 24 to 26 KG increasing with B content. An upper limit of 8 KG for the half-width is attributed to this distribution. The Moessbauer spectra of the Fe 57 nuclei resemble those for the crystalline Fe 75 P 25 /sub -x/B/sub x/ alloys. A fit of the spectra shows a field distribution which suggests the presence of structure. Such a structure may correspond to various Fe sites, also seen in the crystalline alloys. The distributions generally lie between about 160 and 330 KG, with a maximum at about 260 KG. These spectra do not show the presence of Fe nuclei with essentially zero hyperfine field as was obtained for amorphous Fe-Pd-P by Sharon et al. and for amorphous Fe-P by Logan et al. With increasing B content the center of gravity of the Fe distribution shifts to higher values. From a systematic study of the NMR lines and other considerations it is concluded that the P field distribution is broad and its hyperfine field is between 20 and 35 KG for the higher P concentration alloys

  10. A Moessbauer effect study of the bonding in several organoiron carbonyl clusters

    International Nuclear Information System (INIS)

    Long, G.J.; O'Brien, J.F.

    1988-01-01

    After a brief review of the applications of the Moessbauer effect to cyclopentadienyl containing compounds, the chemistry and spectral properties of the various iron carbonyl complexes are described. The electronic properties of a series of trinuclear and tetranuclear organoiron clusters have been investigated through Fenske-Hall self-consistent field molecular orbital calculations, and the results are compared with the Moessbauer effect isomer shifts. A linear correlation is found between the Slater effective nuclear charge, as calculated from the Fenske-Hall partial orbital occupancy factors, and the isomer shift. In these compounds the 4s orbital populations are rather constant. However, the cis and trans isomers of [CpFe(CO) 2 ] 2 have a significantly lower 4s orbital populations. In this case, the reduced 4s population must be accounted for by adding it to the effective nuclear charge to obtain a good correlation with the isomer shift. (orig.)

  11. Moessbauer study of the magnetic phase transformations in SnMn3N

    International Nuclear Information System (INIS)

    Nagy, D.L.; Zimmer, G.J.; Lohner, T.; Senateur, J.P.

    1975-01-01

    Moessbauer measurements were performed on SnMn 3 N with the aim of verifying the magnetic phase transformations at 175 and 230 K and the Neel transition at 475 K as well as of seeking an explanation for the anomalous peak in magnetic susceptibility about 380 K. Moessbauer spectra were taken at several temperatures between 83 and 475 K and evaluated by a least square fitting program. Abrupt changes in the hyperfine field were found at 175, 230 and 350 K indicating first-order magnetic phase transformations at these temperatures; the 350 K transformation is certainly related to the anomaly in susceptibility. About 475 only a smooth change in the hyperfine field was found suggesting the Neel transition to be of the second order. An attempt is made to explain the relatively high hyperfine field in the cubic antiferromagnetic phase. (A.K.)

  12. Application of Moessbauer effect to the study of austenite retained in low carbon steels

    International Nuclear Information System (INIS)

    Azevedo, A.L.T. de; Silva, E.G. da

    1979-01-01

    Moessbauer effect measurements were performed in two samples of low carbon, low alloy steels, one with a bainite granular microstructure and the other a martensitic one. The concentration of the retained austenite was determined in both samples by Moessbauer spectrometry and X radiation, a very good agreement for the sample with a greater austenite content having been observed. From the assumption that the carbon atoms in the f.c.c. matrix repel one another due to Coulomb interactions, giving origin to quadrupolar interactions, it was possible to determine carbon concentration in the MA (Martensite Austenite) components of bainite, the results being in good agreement with the one obtained from metallographic considerations. (I.C.R.) [pt

  13. Application of Moessbauer effect in the study of austenite retained in low carbon steel

    International Nuclear Information System (INIS)

    Azevedo, A.L.T. de; Silva, E.G. da

    1979-01-01

    Moessbauer effect measurements of two samples of low carbon alloy having micro-structure of granular bainite type and martensite type have been done. The concentration of the retained austenite in both samples was determined by Moessbauer effect and x-rays there, being agreement for the higher austenite content sample. Concentration of carbon in the MA (Martensite - Austenite) constituents of bainite is also ditermined, the results being in agreement with metallographic considerations. Carbon enrichments are shown as responsible by the stabilization of the austenite in the granular bainite. Spectra of both samples present three magnetic configurations for α-iron with medium magnetic fields iqual to 335, 307 and 280 KOe. (A.R.H.) [pt

  14. Moessbauer study of the Ru porcelain of Chinese Song Dynasty and Yuan Dynasty

    International Nuclear Information System (INIS)

    Gao Zhengyao; Chen Xiande

    1994-01-01

    The Moessbauer spectra from the glazes of the Song Dynasty and the Yuan Dynasty Ru porcelains and the imitative ancient Ru porcelain are compared and analyzed. It is determined that the original firing atmosphere of the Yuan Dynasty Ru porcelain was reductive. The firing temperature was 1250 ± 20 C. The original firing atmosphere of the Song Dynasty Ru porcelain was also reductive; the firing temperature was above 1200 C. The coloring mechanism of these glazes is discussed. (orig.)

  15. Moessbauer lineshape analysis by the DISPA method

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.

    1986-01-01

    To evaluate the Moessbauer spectral parameters and hence, the structural and magnetic properties the lineshape should be known. A plot of dispersion versus absorption (DISPA plot) for a pure Lorentzian gives a perfect circle. Directions and magnitudes of DISPA distortions from this reference circle point out the kind of line-broadening mechanism observed. A possibility of the application of the DISPA technique in the Moessbauer lineshape analysis is dealt with in this paper. The method is verified on Moessbauer spectra of sodium nitroprusside, natural iron, and stainless steel. The lineshape of an amorphous metallic alloy Fe 40 Ni 40 B 20 is studied by means of the DISPA plots. (author)

  16. Various applications of the Moessbauer effect

    International Nuclear Information System (INIS)

    Legrand, Janine

    1961-06-01

    After having briefly recalled the experiments of resonant absorption of γ photons performed by Moessbauer in 1958 and the interpretation of the results, the author briefly recalls some generalities about the Moessbauer Effect: recoil and thermal agitation, possibility of recoil-free emission, example on tin. The second part addresses the phenomenon of resonant scattering: definition and calculation of atomic scattering, definition of resonant scattering, and experimental measurement of the proportion of Moessbauer photons. The last part reports the study of various bronze samples (the interest of these materials is outlined) [fr

  17. A 121Sb Moessbauer Study of the Chemical State of Antimony in V-Sb-O Mixed-Oxide Catalysts for the Ammoxidation of Propane

    International Nuclear Information System (INIS)

    Stievano, L.; Wagner, F. E.; Zanthoff, H. W.; Calogero, S.

    2002-01-01

    The structural changes of two representative samples of a group of V-Sb-oxide catalysts, a vanadium-rich and an antimony-rich specimen, are investigated by 121 Sb Moessbauer spectroscopy after treatment under propene or hydrogen at 673 K. The as-prepared catalysts contain both Sb(V) and Sb(III) as crystalline and microcrystalline α-Sb 2 O 4 and VSbO 4 , as well as an additional amorphous V 5+ oxide phase. The oxidation state of antimony does not change upon exposure to propene, whereas a partial reduction can be obtained by a more intense reduction under hydrogen. The Moessbauer results indicate that the antimony in VSbO 4 can be reduced more easily than that in α-Sb 2 O 4 , which appears to be more stable. These results are discussed in view of the observed depletion of vanadium at the surface of the catalyst particles under reaction conditions.

  18. Moessbauer study of the fast magnetization reversal forced in permalloy and invar by an external rf magnetic field

    International Nuclear Information System (INIS)

    Kopcewicz, M.

    1978-01-01

    The effect of fast magnetization reversal leading to fast relaxation of the hyperfine field (collapse effect) forced by an external rf magnetic field is studied using the Moessbauer technique for permalloy and invar. The rf collapse and sideband effects are investigated as a function of external rf field, frequency, and intensity. The collapse of the hfs spectrum through unresolved hfs spectrum, triangular shape to a single line, as well as the formation of sidebands is observed. The rf collapse effect is attributed to the rf forced uniform rotation of internal magnetization which causes fast magnetization reversal leading to fast relaxation of the hyperfine field as a result of which the average field at the Moessbauer nuclei is reduced to zero. The difference of the magnetization reversal process in permalloy and invar are discussed. It is shown that the origin of collapse and sideband effects is totaly different: the collapse effect being of purely magnetic origin while the formation of sidebands is due to the rf induced mechanical vibrations of iron atoms within the sample. It is possible to damp sidebands without affecting the collapse effect. The results obtained show that the application of the rf field to ferromagnetic materials gives a unique possibility to force, simulate, and control the relaxation effects in ferromagnetic materials. (author)

  19. Moessbauer effect study of charge and spin transfer in Fe-Cr

    International Nuclear Information System (INIS)

    Dubiel, S.M.; Zukrowski, J.

    1981-01-01

    The influence of temperature and time of annealing on hyperfine fields and isomer shifts has been studied for a range of Fe-Cr alloys containing 1-45 at% Cr. It has been revealed that up to 15 at% Cr neither time or temperature of annealing practically does affect the hyperfine parameters. For more concentrated samples, however, both temperature and time of annealing are important. In particular, the Moessbauer spectrum of Fe-45.5 at% Cr annealed at 700 0 C for 5 h was a single-line indicating that the sample was paramagnetic. The observed changes of the hyperfine fields and the isomer shifts have been interpreted in terms of a spin and charge transfer, respectively. Strong linear correlations between the following quantities have been revealed: the hyperfine field H(0,0) and the isomer shift IS(0,0); the average hyperfine field anti H and the average isomer shift anti Ianti S; the average hyperfine field anti H and the average number of Cr atoms in the first two coordination spheres, anti N. It has been calculated from the first two correlations that a) a change of polarization of itinerant s-like electrons of one electron is equivalent to a change of the hyperfine field of 1602 kOe, and b) on average, a unit change of s-like electron polarization is equivalent to 3277 kOe. The two constants are very close to theoretical estimations, which can be found in literature. Correlation between the hyperfine field and the isomer shift led to a conclusion that the substitution of Fe atoms by Cr ones decreases the density of spin-up electrons on average by 0.026 electrons per one Cr atom in a unit cell. These electrons are most likely trapped by Cr atoms, because the hyperfine field at neighbouring Fe nuclei decreases and the density of charge at those nuclei increases at the rate of 0.029 electrons per one Cr atom in a unit cell. (orig./BHO)

  20. Moessbauer study of iron-carbide growth and Fischer-Tropsch activity

    Energy Technology Data Exchange (ETDEWEB)

    Rao, K.R.P.M.; Huggins, F.E.; Huffman, G.P. [Univ. of Kentucky, Lexington, (United States)] [and others

    1995-12-31

    There is a need to establish a correlation between the Fischer-Tropsch (FT) activity of an iron-based catalyst and the catalyst phase during FT synthesis. The nature of iron phases formed during activation and FT synthesis is influenced by the nature of the gas and pressure apart from other parameters like temperature, flow rate etc., used for activation. Moessbauer investigations of iron-based catalysts subjected to pretreatment at two different pressures in gas atmospheres containing mixtures of CO, H{sub 2}, and He have been carried out. Studies on UCI 1185-57 (64%Fe{sub 2}O{sub 3}/5%CuO/1%K{sub 2}O/30% Kaolin) catalyst indicate that activation of the catalyst in CO at 12 atms. leads to the formation of 100% magnetite and the magnetite formed gets rapidly converted to at least 90% of {chi}-Fe{sub 5}C{sub 2} during activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation. The FT activity was found to be good at 70-80% of (H{sub 2}+CO) conversion. On the other hand, activation of the catalyst in synthesis gas at 12 atms. leads to formation of Fe{sub 3}O{sub 4} and it gets sluggishly converted to {chi}-Fe{sub 5}C{sub 2} and {epsilon}-Fe{sub 2.2}C during activation and both continue to grow slowly during FT synthesis. FT activity is found to be poor. Pretreatment of the catalyst, 100fe/3.6Si/0.71K at a low pressure of 1 atms. in syngas gave rise to the formation of {chi}-Fe{sub 5}C{sub 2} and good FT activity. On the other hand, pretreatment of the catalyst, 100Fe/3.6Si/0.71K at a relatively high pressure of 12 atms. in syngas did not give rise to the formation any carbide and FT activity was poor.