Temat: 76.80.+y - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Local States of Tellurium in Isolated Helical Chains
Autorzy:: Stanek, J.
Fornal, P.
Hafner, S. S.
Pfitzner, A.
Tematy:: 76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2028993.pdf Link otwiera się w nowym oknie
Opis:: The local electronic state of Te in the helical chains of CuXY$\text{}_{2(1-x)}$Te$\text{}_{2x}$ (X = Cl, Br; Y = Se, S) were studied using the Mössbauer spectroscopy of $\text{}^{125}$Te at 10 K and 70 K. The isolated chains of Te in these compounds are less rigid than those in elemental Te. The determined data of quadrupole splitting Δ and Debye temperature Θ$\text{}_{D}$ are indicative of strong local ordering of Te in one of the two non-equivalent crystallographic positions. It was not possible to resolve crystallographic positions by the Mössbauer spectroscopy.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Perturbed γ-γ Angular Correlation Studies of Isostructural Ag$\text{}_{5}$Zn$\text{}_{8}$ and Ag$\text{}_{5}$Cd$\text{}_{8}$ Intermetallic Compounds
Autorzy:: Wodniecki, P.
Wodniecka, B.
Marszałek, M.
Hrynkiewicz, Α. Z.
Tematy:: 76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1933581.pdf Link otwiera się w nowym oknie
Opis:: Perturbed γ-γ angular correlation spectroscopy was applied to study hyperfine interaction parameters for $\text{}^{111}$In probes in intermetallic compounds of D8$\text{}_{2}$ structure. The perturbed γ-γ angular correlation spectra measured in Ag$\text{}_{5}$Zn$\text{}_{8}$ and Ag$\text{}_{5}$Cd$\text{}_{8}$ phases reflect a number, population and symmetry of nonequivalent substitutional sites occupied by the indium probes. The temperature dependences of the observed electric field gradients were measured in the temperature range 37-500 K
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Crystallochemical Structure of Tourmalines Inferred from Mössbauer Spectroscopy
Autorzy:: Kraczka, J.
Pieczka, A.
Tematy:: 76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2028978.pdf Link otwiera się w nowym oknie
Opis:: In the Y octahedra of tourmalines theoretically may occur ions of Fe$\text{}^{2+}$ and Fe$\text{}^{3+}$. The authors discuss Mössbauer measurements and confirm the ordered model of ionic distribution at these sites: the presence of Fe$\text{}^{3+}$ ions in the Y octahedra and Al$\text{}^{3+}$ ions in the Z octahedra. The spectra of different tourmalines annealed at temperatures ranging from 873 K to 1153 K show that Fe$\text{}^{3+}$ ions can occur in both of these sites. The annealing has changed the symmetry of the neighbourhood of iron ions at the octahedral sites. It has been shown that the doublets with QS<2.00 mm/s should not been attributed to Fe$\text{}^{2+}$(Z). Also new results corroborating the existence of the iron ions in the mixed valence state in tourmalines have been presented.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Local versus Bulk Properties of CeAg$\text{}_{2}$Sn$\text{}_{2}$
Autorzy:: Görlich, E. A.
Tematy:: 72.15.Eb
76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1929843.pdf Link otwiera się w nowym oknie
Opis:: Results of electrical resistivity and $\text{}^{119}$Sn Mössbauer effect measurements for two samples of CeAg$\text{}_{2}$Sn$\text{}_{2}$ compound are presented. A sharp drop in resistance of an annealed sample at 3.5 K might have suggested a superconducting transition while for the as-melted specimen only a modest change in ρ vs. T slope is observed at this temperature. Resonance γ-absorption reveals differences and similarities on a microscopic scale between the two samples. The occurrence of certain regions of a long-range magnetic ordering within the CeAg$\text{}_{2}$Sn$\text{}_{2}$ phase is unambiguously demonstrated by the presence of hyperfine splitting. Temperature variation of the hyperfine field follows a molecular field spin-½ function.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Interaction between In Impurity Atoms and Impurity Atoms of Mn and Co Dissolved in Silver
Autorzy:: Sternik, M.
Królas, K.
Tematy:: 61.70.-r
76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1924278.pdf Link otwiera się w nowym oknie
Opis:: The interaction between impurities of two solute elements in metal hosts leads to a non-random distribution of impurity atoms among the lattice sites. Experimental studies of this distribution provide quantitative information on the energy involved in the formation of an individual impurity-impurity pair. The perturbed angular correlation measurements performed with $\text{}^{111}$In probe atoms and Mössbauer spectra of $\text{}^{57}$Co are used to derive the interaction energy of In atoms with Mn and Co atoms introduced into silver matrix. It is demonstrated that In atoms attract Mn and Co atoms and in the case of In-Mn pair the interaction energy value was determined. The obtained results are discussed in the frame of the semiempirical model and the recent first principles theoretical calculations.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: A Search for Thermal Vacancies Forming Close Frenkel Pairs in Fe-Cr Alloys
Autorzy:: Chojcan, J.
Tematy:: 61.72.Ji
76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2028967.pdf Link otwiera się w nowym oknie
Opis:: The room temperature Mössbauer spectra of $\text{}^{57}$Fe were measured for the bcc Fe$\text{}_{0.948}$Cr$\text{}_{0.052}$ solid solution quenched into water being at about 295 K from different temperatures not exceeding 1000 K, i.e. from the temperatures for which probabilities of formation of "clear" (Schottky) vacancies as well as vacancies forming the separate interstitial-vacancy (Frenkel) pairs are negligibly low. The obtained data were analysed in terms of concentration of unoccupied places in the 14-site surroundings of an $\text{}^{57}$Fe Mössbauer probe in the sample. It turned out that the concentration of vacancies detected by the probe increases with temperature very rapidly - at the rate of about 10$\text{}^{-4}$ K$\text{}^{-1}$. The result may suggest that the Mössbauer probe is sensitive to a possible thermal distortion of the lattice or creation of very close Frenkel pairs (the interstitial is the nearest neighbour of the vacant lattice site).
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Process of Amorphization Induced by Mechanical Alloying of Iron with Tungsten and Niobium
Autorzy:: Jartych, E.
Oleszak, D.
Żurawicz, J.
Tematy:: 76.80.+y
61.10.-i; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2028976.pdf Link otwiera się w nowym oknie
Opis:: Mechanical alloying method was used to synthesise powders of iron with tungsten and niobium. Mössbauer spectroscopy and X-ray diffraction have been applied to monitor the progress in solid-state reactions. In the case of Fe-W system, exhibiting a positive heat of mixing, no trace of amorphization was observed for 20 and 33 at.% of W, as the calculations of phase diagram (CALPHAD) method suggest. During the mechanical alloying process, two solid solutions Fe(W) and W(Fe) were obtained. Mössbauer measurements allowed to recognise the Fe(W) solid solution as a ferromagnetic phase, while the W(Fe) solid solution as a paramagnetic one. In the case of Fe-Nb system, exhibiting a negative heat of mixing, single phase amorphous alloys were synthesised during mechanical alloying of iron with 48 and 64 at.% of Nb. For both investigated compositions, the final products of mechanical alloying processes were amorphous paramagnetic alloys.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Structural Relaxation in $Fe_{78}Nb_{2}B_{20}$ Amorphous Alloy Studied by Mössbauer Spectroscopy
Autorzy:: Kansy, J.
Hanc, A.
Rasek, J.
Haneczok, G.
Pająk, L.
Stokłosa, Z.
Kwapuliński, P.
Tematy:: 75.75.+a
76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1506588.pdf Link otwiera się w nowym oknie
Opis:: 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 Mössbauer 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.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Maximum Entropy Method in Mössbauer Spectroscopy - a Problem of Magnetic Texture
Autorzy:: Satuła, D.
Szymański, K.
Dobrzyński, L.
Tematy:: 76.80.+y
02.60.-x; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1506656.pdf Link otwiera się w nowym oknie
Opis:: A reconstruction of the three dimensional distribution of the hyperfine magnetic field, isomer shift and texture parameter z from the Mössbauer 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.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Temperature Dependence of Magnetization in Transition Metal Ultrathin Films of Various Thicknesses
Autorzy:: Świrkowicz, R.
Tematy:: 75.70.Ak
76.80.+y; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1891839.pdf Link otwiera się w nowym oknie
Opis:: Temperature dependence of the local magnetization in the spin-wave regime is calculated within the framework of the multiband model for ultrathin films consisting of 5, 7 and 9 monolayers. The temperature range in which the calculated results can be fitted to the Bloch T$\text{}^{3}$ $\text{}^{/}$ $\text{}^{2}$ law is found in all cases. The Bloch coefficient Bay corresponding to temperature dependence of the average film magnetization is found to be proportional to 1/D, where D is the thickness of the film. The spatial distribution of the local magnetization is obtained. The Bloch coefficient corresponding to the surface layer appears to be greater than the one corresponding to the central layer, namely B$\text{}_{s}$ > B$\text{}_{c}$. The ratio B$\text{}_{s}$/B$\text{}_{c}$ is increasing with an increase of the film thickness. The calculated results are well consistent with experimental ones obtained for ultrathin films of various thicknesses.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "76.80.+y" wg kryterium: Temat