Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Refine search results

Journals help

  1. 32 Acta Physica Polonica A

Years help

  1. 3 2017

  2. 2 2016

  3. 2 2015

  4. 7 2014

  5. 4 2012

More...
Authors help

  1. 2 Byakov V.

  2. 2 Cherkezova-Zheleva Z.

  3. 2 Degmová J.

  4. 2 Dekan J.

  5. 2 Dubiel B.

More...
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 32

Number of results on page
first rewind previous Page / 2 next fast forward last

Search results

Search:
in the keywords:  82.80.Ej
help Sort By:

help Limit search:
first rewind previous Page / 2 next fast forward last
1
Content available remote

Mössbauer-Effect Study of Calciomagnetites

100%
Dubiel S., Cieślak J., Orewczyk J., Jasieńska S.
Acta Physica Polonica A
|
1998
|
vol. 93
|
issue 3
547-561
EN
Ca_{x}Fe_{3-x}O_{4} samples, with x ≤ 0.28 , prepared from α-Fe_{2}O_{3} and CaO by the Bridgman method were investigated by means of ^{57}Fe Mössbauer spectroscopy. Room temperature spectra gave evidence that the samples were multiphase, the calciomagnetite being the dominant phase with a contribution of 73% to 99%, depending on the sample. Analysis of the subspectra associated with the calciomagnetite gave evidence that Ca-ions reside on the tetrahedral (A) sites and have not random distribution. Their presence on those sites causes a reduction of the hyperfine field at Fe nuclei occupying the octahedral positions (B) by 12.3(1.0) kOe per one Ca-ion and a decrease in the average hf field, 〈H_{B}〉/dx, at the rate of 29 kOe/mol% for x ≤ 0.07 and of 387 kOe/mol% for larger x. In addition, a linear correlation between 〈H_{B}〉 and the average isomer shift, 〈I_{B}〉, was revealed to hold. It indicates that addition of Ca-ions into the magnetite causes a decrease in the spin-density and an increase in the charge-density at Fe nuclei occupying the B-sites.
2
Content available remote

PIXE Analysis of Persian Miniature Used in 16th Century Poetry Manuscript

100%
Kakuee O., Fathollahi V., Oliaiy P., Lamehi-Rachti M., Sharafi M., Kasiri M.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 5
1244-1248
EN
In Persian culture, precious poetry manuscripts used to be decorated by miniature paintings and illuminations to visualize the story of the poem to the reader. The Joseph and Zulaikha story written in Persian by Jami (1414-1492) is one of the poetry books which has attracted considerable attention and has been copied and decorated by calligraphers and painters several times. This paper will focus on characterization of Persian miniature of the Joseph and Zulaikha created in the 15th-16th century in the Bokhara school. To collect the required information for preservation, restoration, and authenticity of the masterpiece, the elemental composition of the applied pigments in the miniature paintings as well as the elemental composition of the employed ink and paper was analyzed by external PIXE.
3
Content available remote

Mössbauer Investigations and Photoemission Studies of the Fe 3s Spin Splitting in Some Fe-Ni Alloys

100%
Kądziołka-Gaweł M., Zarek W., Talik E., Popiel E.
Acta Physica Polonica A
|
2008
|
vol. 114
|
issue 6
1493-1500
EN
The magnetic properties, crystal and electronic structure for Fe_{1-x}Ni_x (x=0.30, 0.325, 0.375) alloys and austenitic steel were studied using magnetostatic, Mössbauer effect methods, X-ray diffraction and X-ray photoelectron spectroscopy. The compositions of the investigated Fe-Ni alloys were chosen like that to exist on left, right and in inside of invar range. Two different magnetic moments (low and high) of Fe atom were observed. Measurement results do not show antiferromagnetic order in Fe-Ni alloys.
4
Content available remote

The Crystal Structure and Magnetic Properties οf Selected fcc FeNi and Fe_{40}Ni_{40}B_{20} Alloys

100%
Kądziołka-Gaweł M., Zarek W., Popiel E., Chrobak A.
Acta Physica Polonica A
|
2010
|
vol. 117
|
issue 2
412-414
EN
The crystal structure and magnetic properties of polycrystalline alloys Fe_{62.5}Ni_{37.5}, Fe_{60}Ni_{40}, Fe_{50}Ni_{50} obtained by arc-melting and Fe_{40}Ni_{40}B_{20} alloy obtained by melt spinning technique were investigated by X-ray, magnetostatic and Mössbauer effect methods. The X-ray measurements show that Fe_{40}Ni_{40}B_{20} alloy has a face-centered structure (fcc) which means that boron did not cause an amorphous rendering. The lattice constants for this alloy (a = 3.53 Å) is smaller than for FeNi alloys (a > 3.57 Å) which suggests that boron atoms were built-in in the crystal lattice. The Curie temperature of this alloy is more than 150 K higher in comparison with the of FeNi alloys, but the magnetic moment connected with this alloy is more than 0.17 μ_{B}/atom smaller than the magnetic moments of FeNi alloys. The shape of hyperfine field distribution for Fe_{40}Ni_{40}B_{20} is similar to the shape of hyperfine field distribution for the investigated fcc Fe_{62.5}Ni_{37.5} alloy, but both are different from another investigated hyperfine field distribution of FeNi alloys.
5
Content available remote

Mössbauer Studies of Core-Shell Nanoparticles.

80%
Kalska-Szostko B., Cydzik M., Satuła D., Giersig M.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 1
15-17
EN
The ferrite magnetic nanoparticles with core-shell structures were obtained in two step preparation process. The Mössbauer spectra obtained for particles of pure maghemite or magnetite and two layered core-shell one the magnetite on maghemite and maghemite on magnetite are very different from each other. The presented results show that interparticle and intraparticle interaction plays important role in overall magnetic properties as well.
6
Content available remote

Oxidation of Stainless Steel by Laser Cutting

80%
Amulevičius A., Mažeika K., Sipavičius Č.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 5
880-885
EN
Oxidation of erosion products was studied by means of the Mössbauer spectroscopy and X-ray diffraction methods when the strip of stainless steel was cut with the laser. Different content of wustite and chromium doped magnetite Fe_{3-x}Cr_{x}O_{4} was found in the samples of erosion products depending on the place where the erosion products were collected in relation to the cutting slot. Conversion electron Mössbauer spectroscopy data showed that more magnetite was found at the surface while wustite distributes in the whole volume of particles of erosion products.
7
Content available remote

Bivalve Characterization Using Synchrotron Micro X-Ray Fluorescence

80%
Jones K., Bronson S., Brink P., Gordon C., Mosher-Smith K., Brown M., Chaudhry S., Rizzo A., Sigismondi R., Whitehurst M., Lukaszewski A., Kranz D., Bland K., Gordan D., Lobel J., Sullivan J., Metzger M., O'Shea C., Harris C., Arezzo R., Kambhampati M.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 2
477-481
EN
Bivalves, oysters, mussels, and clams are important constituents of riverine and estuarine ecosystems. Their shells and soft tissues provide information on the environments in which they live. Since they are filter feeders, they also are factors in improving water quality through removal of particulate matter from the water column. Finally, they are a valuable food source that has substantial economic value. Hence, characterization of shells and soft tissues is useful for improved understanding of these factors. Here, we used X-ray microprobes and computed microtomography facilities at the Brookhaven National Synchrotron Light Source to investigate elemental distributions in bivalves taken from locations around New York, Washington, DC, and New Orleans, LA. The results form the initial basis for compilation of a database of relevant parameters that can serve for tracking environmental changes and for assessing toxicity of particular metals. The work was enabled by active collaboration with students from the several regions, community groups, and research scientists. The collaboration was facilitated through use of web conferencing between Brookhaven National Laboratory and the varied locations.
8
Content available remote

Application of Positron Spectroscopy for the Detection of Nanostructures in Water-Alcohol Mixtures

80%
Stepanov P., Byakov V., Zaluzhnyi A.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 3
767-769
EN
Analysis of the o-Ps lifetimes concentration dependences in water-propanol mixtures (with and without CoCl_2 additive) shows that this mixture looks like an emulsion of alcohol micelles in water at propanol mole fractions 0.1-0.4.
9
Content available remote

Study of Magnetic and Structural Properties of Non-Stoichiometric NiZn Ferrites Prepared by Wet Method

80%
Grusková A., Sláma J., Ušáková M., Šoka M., Dosoudil R., Degmová J.
Acta Physica Polonica A
|
2010
|
vol. 118
|
issue 5
780-781
EN
An iron-deficient (Ni_{0.33}Zn_{0.67})_{1 + x}Fe_{2 - x}O_4 and stoichiometric Ni_{0.45}Zn_{0.55}Fe_2O_4 prepared by a wet method were studied using the Mössbauer spectroscopy and thermomagnetic measurements. For the iron-deficient sample the T_{C} is twice as large and the temperature coefficient of initial permeability is two orders of magnitude lower in comparison with the stoichiometric samples. The results are supplemented by the frequency dependence of the complex permeability.
10
Content available remote

Zone-Plate Based Nanospectroscopy with Soft X-Rays at the SLS

80%
Fink R., Hub C., Tzvetkov G.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 2
462-466
EN
With the advance of nanostructuring techniques and the availability of third-generation synchrotron sources, Fresnel-type zone plate optics is widely used for nanospectroscopic investigations with resolutions of several 10 nm. Whereas hard X-rays commonly use diffraction or elemental contrast (e.g. using X-ray fluorescence), soft X-rays are favored to utilize the spectroscopic contrast in the near-edge region of the absorption edge. In particular, for soft materials, the relevant C-, N- and O 1s absorption edges show distinct resonances which allow fingerprint-type chemical identification, even in water surroundings. Few selected examples from modern material science will be discussed to demonstrate that the combination of X-ray absorption spectroscopy with high spatial resolution yields new insight into the nanoscale properties of these materials.
11
Content available remote

Compensation of Roentgen Exciting System Instability in Conducting X-Ray Fluorescence Analysis of Bioassays

80%
Galchenko S., Kirilenko E., Fokov G.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 3
531-535
EN
Detailed analysis of the backscattering peak in the X-ray fluorescence spectrum was carried out using the Monte Carlo method which is the base of the computer code "SNEGMONT" for simulating the transport of electrons and photons. The calculations show that the intensity of the backscattering peak is directly proportional to the intensity of the exciting radiation. It was found that the intensity of analyzed elements' lines has a strict relation with the intensity of the backscattering peak. The example of determination of lead and zinc concentrations in bioassay is presented. The simulation of an eightfold change of the exciting X-rays intensity which taking into account the obtained strict relation allows to determine the true concentration of elements with an error of no more than 3%.
12
Content available remote

Effect of Mechanochemical Treatment on Magnetic Properties of Nanodimensional Magnetite-Type Materials

80%
Cherkezova-Zheleva Z., Zaharieva K., Buchkov K., Blagoev B., Mitov I.
Acta Physica Polonica A
|
2014
|
vol. 126
|
issue 4
912-915
EN
The presented study compares magnetic properties of Ni-doped magnetites Ni^{2+}_{0.5}Fe^{2+}_{0.5}Fe^{3+}_{2}O_{4} to magnetite (Fe_3O_4) sample. Physicochemical properties of materials were registered by means of X-ray powder diffraction, Mössbauer spectroscopy, saturation magnetization and physical properties measurement systems. It was obtained that used preparation procedures lead to synthesis of single phase spinel materials with close nanodimensional size about 8-12 nm. Mechanochemically synthesized sample shows better magnetic properties as lower blocking temperature of superparamagnetic state and minimal coercivity in comparison to other studied materials.
13
Content available remote

Applications of FTIR and ^{57}Fe Mössbauer Techniques in Studies of Recently Excavated Indian Archaeological Pottery

80%
Dhanapandian S., Manoharan C., Sutharsan P.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 3
592-598
EN
The Fourier transform infrared absorption spectra and ^{57}Fe Mössbauer spectra have been recorded at room temperature for the recently excavated archaeological pottery sherds. FTIR spectroscopy is used to estimate the lower limit of firing temperature and firing nature of the pottery sherds, and it is confirmed by the results of the Mössbauer technique results. The results show that the ^{57}Fe Mössbauer and FTIR spectra of few pottery sherds of Perumalpattu and Theriruveli are nearly identical, indicating that they may belong to the same origin. ^{57}Fe Mössbauer spectra of black coloured sherds show the presence of Fe^{2+} ions which confirm the relation between the black colour in pottery and the existence of non-magnetic FeO compound, resulting from the reducing atmospheric condition during firing. FTIR results of reddish pot sherds show the presence of significant amount of Fe_2O_3/α-Fe_2O_3, which confirms again the relationship between the state and form of iron present in the pottery and its colour.
14
Content available remote

Mechanochemical Preparation and Properties of Nanodimensional Perovskite Materials

80%
Cherkezova-Zheleva Z., Paneva D., Yordanova I., Shopska M., Kolev H.
Acta Physica Polonica A
|
2014
|
vol. 126
|
issue 4
916-920
EN
The study is focused on the synthesis of LaMO_3 (M = Co, Fe, Mn) perovskite materials using combination of precipitation of precursors and mechanical milling at room temperature. Physicochemical properties of products at each step of preparation were studied by powder X-ray diffraction, Mössbauer spectroscopy, infrared spectroscopy (in the middle and far regions) and X-ray photoelectron measurements. As-prepared perovskite powders are composed of nanoparticles with very fine crystallite size (about 15 nm) in all cases. The materials have also high dispersion, high extent of microstrains and high level of oxygen vacancies which is very important in relevance to their use as heterogeneous catalysts.
15
Content available remote

Chemical, Magnetic and X-Ray Diffraction Studies of the Sediments from Oil Field in Argentina

80%
Kopeć M., Kąc M., Bałanda M., Budziak A., Kąc S., Perzanowski M., Góra M.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 2
566-570
EN
Chemical, magnetic, and phase composition analysis of deposits taken from sedimentation tank from oil plant in Argentina was carried out. Energy dispersive spectroscopy indicates iron as a main sediment component with the site dependent fraction ranging from 11% to 78% (weight percentage). Moreover, large fractions of sulfur (4%-33%), oxygen (8%-28%), calcium (1%-14%), and silicon (1%-11%) were found. The chemical analysis performed with wet chemical methods also indicated Fe as a main component (about 35%), additionally a large fraction ( ≈ 15%) of the sulfur and under 10% fractions of calcium ( ≈ 7%), carbon ( ≈ 6%), and silicon ( ≈ 5%) were found in the sample. The phase composition studies performed using X-ray diffraction showed magnetite - Fe_3O_4, goethite - α-FeOOH, lepidocrocite - γ-FeOOH, siderite - FeCO_3, and iron-sulfur compounds (mackinawite - FeS, stoichiometric FeS, greigite - Fe_3S_4) and other compounds like aragonite - CaCO_3, calcite - CaCO_3, anorthite - CaAl_2Si_2O_8, quartz - SiO_2 and barium sulphate Ba(SO_3)_{0.3}(SO_4)_{0.7}. Studies performed by the Mössbauer spectroscopy, confirmed presence of majority of compounds identified by X-ray diffraction. Magnetic AC susceptibility measurements show that magnetite is a main component of the studied deposit. High concentration of the magnetic compounds deposited in the sedimentation tank points to the advisability to install the magnetic device designed to support water treatment processes, i.e.: flocculation, coagulation, sedimentation, and filtration. This device could simultaneously inhibit microbiological and chemical corrosion.
16
Content available remote

Secondary Radiation Field Effects for the CEM Spectra

80%
Ruebenbauer K., Błachowski A., Żukrowski J.
Acta Physica Polonica A
|
2010
|
vol. 117
|
issue 6
953-961
EN
The secondary resonant radiation field and resonant absorption thickness effects on the Conversion Electron Mössbauer Spectroscopy spectra are analyzed for highly enriched resonant targets. It is shown that secondary field effect is important for the thick α-Fe foil enriched in the resonant isotope. Even for the polycrystalline sample traces of the coherent resonant field have been detected as the distortion of lines. Secondary field is discussed in detail. Suitable approximations to treat spectra originating from targets with significant resonant thickness developing secondary field composed of the incoherent and coherent parts are introduced. Finally, the formalism is applied to the high quality spectrum recorded for the enriched iron foil and correlation between contribution due to the secondary field and experimental line shape is investigated.
17
Content available remote

The Mössbauer Spectroscopy and Analytical Investigations οf the Polycrystalline Compounds with General Formula Zn_xSn_yCr_zSe_4

80%
Jendrzejewska I., Hanc A., Zajdel P., Kita A., Goryczka T., Maciążek E., Mrzigod J.
Acta Physica Polonica A
|
2008
|
vol. 114
|
issue 6
1591-1597
EN
We present combined X-ray powder diffraction and Mössbauer ^{119}Sn studies of polycrystalline compounds with a general formula Zn_xSn_yCr_zSe_4 (where x+y+z ≈3). The obtained single-phase compounds crystallize in the spinel cubic structure - Fd3m. Tin ions are found to occupy both tetrahedral and octahedral sublattices. On the contrary to the strong tetrahedral site preference energy of Sn, the presented data strongly suggest that the increase in lattice parameters with Sn doping is caused by Sn ions that incorporated into octahedral positions. A quadrupole and isomer shifts of ^{119}Sn in (SnSe_4)^{6-} and (SnSe_6)^{4-} are also reported.
18
Content available remote

Olefin Hydrogenation with Single-Site Gold

80%
Szlachetko J., Lothschütz C., Sá J.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 4
940-943
EN
Butene hydrogenation activity is intimately connected with the occupied and unoccupied electronic states of gold active site. We prepare well-defined Au(III) sites in IRMOF-3 structure, and tuned the metal density-of-states by replacing the substituent group of the coordinating group at position 5. Resonant inelastic X-ray scattering experiments and theoretical calculations revealed an increase in unoccupied 5d states of Au when the substituent group is a donating group, which leads to a dramatic increase in catalytic activity.
19
Content available remote

The Mössbauer and X-Ray Studies οf the Spinel Ferrites Cu_{0.5}Fe_{0.5}Cr_2Se_4 and Cu_{0.2}Fe_{0.8}Cr_2Se_4 Prepared by the Ceramic Method

80%
Maciążek E., Hanc A., Sitko R., Zawisza B., Jendrzejewska I., Mrzigod J.
Acta Physica Polonica A
|
2008
|
vol. 114
|
issue 6
1599-1603
EN
Seleno-spinels with nominal chemical composition Cu_{0.5}Fe_{0.5}Cr_2Se_4 and Cu_{0.2}Fe_{0.8}Cr_2Se_4 were prepared as polycrystalline samples using ceramic method. The assumed composition was verified by wavelength-dispersive X-ray fluorescence spectrometry. The X-ray analysis was carried out in order to make phase analysis and to compare its results with those obtained with the Mössbauer spectroscopy.
20
Content available remote

Primary Radiolytic Reactions in the Auger Blob Formed by Radioactive Transformation of ^{57}Co into ^{57}Fe in Frozen Aqueous Medium

80%
Stepanov S., Perfil'ev Y., Byakov V., Kulikov L.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 3
843-845
EN
The emission of the Auger electrons during the formation of the Mössbauer nucleus ^{57}Fe leads not only to the formation of multicharged ^{57}Fe^{n+} ion, but also to the appearance of the Auger blob, a cloud of several hundreds of ion-electron pairs (H_2O^{+}, e¯) in the solvent around the Fe ion. Fast radiation-chemical reactions therein determine the experimentally observable ratio of the yields of final chemically stable charged states of the Mössbauer ions (Fe^{3+} and Fe^{2+}). This ratio strongly depends on reaction rates constants between H_2O^{+}, e¯, and the solute S. We have shown that in contrast to radiation chemical data the reactivity of NO_{3}^{-} anions with quasi-free track electrons in frozen aqueous solutions exceeds those of H_{3}O^{+}, ClO_{4}^{-}, and HSO_{4}^{-} ions only by a factor of three instead of ≈ 100 which follows from the radiation chemical experiments.
first rewind previous Page / 2 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.