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1

Mean hyperfine fields at 57Fe in dilute iron-based alloys studied by Mössbauer spectroscopy

Idczak R., Konieczny R., Chojcan J.

Nukleonika

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2015

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Vol. 60, No. 1

39--42

EN

The room temperature Mössbauer spectra of 57Fe were measured for numerous dilute iron-based alloys Fe1-xDx (D = Al, Co, Cr, Mn, Mo, Ni, Os, Pt, Re, Ru, Ta, Ti, V, W, Zn), annealed at 1270 K for 2 h before the measurements. The spectra were analyzed using the Hesse–Rübartsch method in order to determine the mean hyperfi ne magnetic fi eld at the 57Fe nuclei as a function of concentration x of the minority component of the alloy. As the binary alloys are one-faze solid solutions of an element D in iron, a linear relationship between and x is observed. The result supports the suggestion that Mössbauer spectroscopy is a useful tool for the study of dissolution of different elements in iron.

2

Interactions between osmium atoms dissolved in iron observed by the 57Fe Mössbauer spectroscopy

Konieczny R., Idczak R., Chojcan J.

Nukleonika

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2015

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Vol. 60, No. 1

75--79

EN

The room temperature 57Fe Mössbauer spectra for binary iron-based solid solutions Fe1−xOsx, with x in the range 0.01 ≤ x ≤ 0.05, were analyzed in terms of binding energy Eb between two Os atoms in the Fe-Os system. The extrapolated values of Eb for x = 0 were used for computation of enthalpy of solution of osmium in iron. The result was compared with that resulting from the cellular atomic model of alloys by Miedema. The comparison shows that our fi ndings are in qualitative agreement with the Miedema’s model predictions.

3

Thermodynamic properties of Au-Fe alloys studied with 57Fe Mössbauer spectroscopy

Idczak R., Konieczny R., Chojcan J.

Nukleonika

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2013

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Vol. 58, No. 1

93-97

EN

The room temperature Mossbauer spectra of 57Fe were measured for Au1.xFex alloys with x in the range 0.01 less-than or equal to x less-than or equal to 0.03. The obtained data were analysed in terms of short range order parameter (SRO) and the binding energy Eb between two iron atoms in the studied materials using the extended Hrynkiewicz-Krolas idea. The estimated negative SRO parameters and the positive binding energy suggest ordering tendencies in Au-Fe alloys at low iron concentration. The extrapolated value of Eb for x = 0 was used for the computation of enthalpy of the solution of Fe in Au. The results were compared with the corresponding data derived from calorimetric measurements, previous Mossbauer experiments and resulting from the cellular atomic model of alloys by Miedema.

4

Positron annihilation in precious and common opals

Chojcan J., Sachanbiński M., Idczak R., Konieczny R.

Nukleonika

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2013

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Vol. 58, No. 1

225-228

EN

The nano-porosity structure of several non-crystalline opal samples of different origin was investigated with positronium atoms. The obtained data show that the structure depends on both the kind of opal (precious, common or hyalite) as well as the place of its creation (sedimentary or volcanic rocks). The sizes of the pores "seen" by positronium atoms are relatively small, not greater than about 1 nm for all studied samples which may suggest that the pores are located inside the silica matter from which the samples are made. Moreover, the pores detected in the "sedimentary" precious opals are smaller and have less diverse sizes than those found in 'sedimentary" common opals and "volcanic' precious opals.

5

Thermal defects in iron-based Fe-V solid solutions

Chojcan J., Beliczyński J.

Nukleonika

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2003

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Vol. 48,suppl.1

17-20

EN

Room temperature 57Fe Mössbauer spectra, positron annihilation lifetime data, X-ray diffraction patterns, and energy distributions of X-rays induced by an electron beam were measured for samples of the Fe0.947V0.053 solid solution quenched from different temperatures not exceeding 1250 K, into water being at about 295 K. The data were analysed in terms of concentration of unoccupied sites in the 14-site neighbourhood of the 57Fe Mössbauer probe in the specimens. It was found that the vacancy formation enthalpy amounts to 0.8 š 0.2 eV in the materials studied.

6

Związki wrażliwościowe w równoległych strukturach połączeń aktywnych czwórników dualnych

Chojcan J., Kukiełka A.

Zeszyty Naukowe. Elektronika / Politechnika Śląska

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2000

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z. 12

69-86

PL

W artykule rozważano obwody w postaci połączenia równoległego czwómików aktywnych. Dokonano inferencji podobieństwa dualnego z inwersją i konwersją impedancji oraz wykorzystano odpowiednie zależności wzmocnień napięciowego i prądowego tych układów [6] celem przeprowadzenia analizy wrażliwościowej układu czwómików połączonych równolegle. Uzyskane związki są rozszerzeniem dotychczasowej teorii i mogą być pożyteczne przy transformacji układów ze wzmacniaczami napięciowymi na układy z konwejerami prądowymi (CC).

EN

In the paper four-terminal active networks in paralell connection are considered. The transfer and sensitivity properties of similar networks are given. The transform of connections for passive and active two-ports and changes of their internal structures have been noticed. Some interesting properties of sensitivity of networks functions of similar networks with two-ports are derived.

7

Transmisja danych z widmem rozproszonym

Chojcan J., Dustor A.

Zeszyty Naukowe. Elektronika / Politechnika Śląska

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2000

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z. 12

201-219

PL

W pracy przedstawiono podstawy działania systemów z rozproszonym widmem Spread Spectrum Direct Sequence na przykładzie zbudowanego nadajnika i odbiornika transmitującego dane poprzez sieć energetyczną niskiego napięcia. Przedstawiono również uzyskane parametry transmisji oraz pokazano wpływ długości kodu na odporność odbiornika na zakłócenia.

EN

The paper includes a description of Spread Spectrum Direct Sequence systems. For transmitting data over electric power distribution circuits a pair of transmitter and receiver was built. The paper presents accomplished transmission parameters and the influence of the length code on the noise immunity of receiver.