Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Štĕpánková, H." wg kryterium: Autor

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-11 z 11
    Tytuł:
    $\text{}^{57}$Fe Hyperfine Field Anisotropy in Ferrites and its Relation to the Non-Uniformity of the Ionic Surrounding
    Autorzy:
    Štepánková, H.
    Englich, J.
    Kohout, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2013366.pdf
    Data publikacji:
    2000-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.60.-k
    75.50.Gg
    Opis:
    The hyperfine field anisotropy tensors, obtained from analysis of $\text{}^{57}$Fe NMR spectra for iron sites in various magnetic oxides (barium hexaferrite, lithium spinel, magnetite and yttrium-iron garnet) were used to investigate the relation between the hf anisotropy and surrounding ionic arrangement. While a reasonable correlation has been found when the distribution of the nearest cations was considered, no correlation was obtained between the hyperfine field anisotropy and the positions of the nearest oxygen anions.z
    Źródło:
    Acta Physica Polonica A; 2000, 97, 5; 757-760
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hyperfine Fields and Lattice Deformations in Ba and Sr Hexaferrites
    Autorzy:
    Chlan, V.
    Kouřil, K.
    Štěpánková, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1387540.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    31.15.aj
    75.30.Et
    76.60.Jx
    Opis:
    Hyperfine magnetic fields on ⁵⁷Fe nuclei in Sr and Ba hexagonal ferrites are calculated in dependence on unit cell volume and c/a ratio. By analysing the local deformations of Fe-O-Fe triads the results are explained as changes to contact hyperfine field due to Fe-O covalency effects and supertransferred hyperfine fields. Most pronounced effect is found for bipyramidal iron Fe(b) where the total contact field is reduced due to noticeable shortening of Fe(b)-O bonds.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 594-596
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study of Y-type Hexaferrite by Means of $\text{}^{57}Fe$ NMR and Electronic Structure Calculations
    Autorzy:
    Chlan, V.
    Kouřil, K.
    Štěpánková, H.
    Řezníček, R.
    Englich, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1378196.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.05.Qr
    75.85.+t
    75.50.Gg
    31.15.E-
    Opis:
    The electron structure and site preferences of Zn and Fe cations in Y hexaferrite system were calculated. The hyperfine magnetic fields on $\text{}^{57}Fe$ nuclei were determined using WIEN2k and corrections for hyperfine contact interaction. The calculated fields were compared to $\text{}^{57}Fe$ nuclear magnetic resonance (NMR) experiment in $Ba_2Zn_2Fe_{12}O_{22}$ single crystal with an aim of interpretation of experimental NMR spectrum.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 42-43
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    NMR Study of Multiferroic Iron Niobate Perovskites
    Autorzy:
    Kouřil, K.
    Chlan, V.
    Štěpánková, H.
    Řezníček, R.
    Laguta, V.
    Raevski, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/1384854.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.60.-k
    76.60.Jx
    75.10.Nr
    75.85.+t
    Opis:
    We present $\text{}^{93}Nb$, $\text{}^{207}Pb$ and $\text{}^{135,137}Ba$ NMR study of multiferroic lead iron niobate and barium iron niobate ceramics. We ascribe development of NMR spectra on cooling below room temperature to magnetism of ferric ions close to resonating nuclei and introduce a framework capable of describing key features of the observed temperature induced changes. We show that the ferric ions have much stronger influence on hyperfine fields at nuclei of large cations in lead compound and estimate strength of interaction of superantiferromagnetic clusters.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 234-236
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hyperfine Field in YIG with Charged Substitution
    Autorzy:
    Kohout, J.
    Štĕpánková, H.
    Englich, J.
    Novák, P.
    Kučera, M.
    Nitsch, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2013158.pdf
    Data publikacji:
    2000-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.60.-k
    75.50.Gg
    Opis:
    $\text{}^{57}$Fe NMR spectra were measured on thin films of yttrium iron garnet with divalent (Ca$\text{}^{2+}$) and tetravalent (Ge$\text{}^{4+}$) cation substitutions using the spin echo technique at 4.2 K. A series of Y$\text{}_{3-x}$Ca$\text{}_{x}$Fe$\text{}_{5-x}$Ge$\text{}_{x}$O$\text{}_{12}$ samples with 0 ≤ x ≤ 0.0 5 was prepared by an epitaxial growth from BaO/B$\text{}_{2}$O$\text{}_{3}$/BaF$\text{}_{2}$ flux on gadolinium gallium garnet substrate. Satellite lines corresponding to the iron ions having the Ge$\text{}^{4+}$ and Ca$\text{}^{2+}$ in their neighbourhood were identified. The sample with the germanium content of x(Ge) = 0.004 and (110) substrate orientation was used for a detailed study: NMR spectra of this sample were measured in an external magnetic field of 0.1 T applied along several directions in the plane of the film. The modification of the isotropic part and the anisotropy tensor of the hyperfine interaction caused by the Ge$\text{}^{4+}$ substituent were obtained from the experimental data. The results were compared with those previously reported for trivalent substitution (Ga$\text{}^{3+}$).
    Źródło:
    Acta Physica Polonica A; 2000, 97, 3; 519-522
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structure of Iron Oxide Nanoparticles Studied by $\text{}^{57}Fe$ NMR
    Autorzy:
    Křišťan, P.
    Chlan, V.
    Štěpánková, H.
    Řezníček, R.
    Görnert, P.
    Payer, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1378149.pdf
    Data publikacji:
    2014-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.60.-k
    75.50.Gg
    75.50.Tt
    Opis:
    In this work we apply nuclear magnetic resonance (NMR) spectroscopy of $\text{}^{57}Fe$ nuclei for investigation of submicron and nanocrystalline iron oxide systems. The studied iron oxide particles are obtained from ferrous hydroxide gels (prepared from $FeCl_{2}$ and KOH) by aging at elevated temperatures (90 °C) with $KNO_{3}$ as oxidant. The $\text{}^{57}Fe$ NMR spectra of the samples are measured in temperature range 4.2-370 K in a zero external magnetic field. Signals of $\text{}^{57}Fe$ nuclei assigned to tetrahedral and octahedral iron sites are well resolved. The NMR spectra and their temperature dependences are compared with those of stoichiometric and nonstoichiometric magnetite single crystals, as well as with samples of maghemite.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 1; 138-139
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Antisite Defects in Epitaxial Films of Lutetium Doped Yttrium Iron Garnets Studied by Nuclear Magnetic Resonance
    Autorzy:
    Chlan, V.
    Štěpánková, H.
    Englich, J.
    Řezníček, R.
    Kouřil, K.
    Kučera, M.
    Nitsch, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1534129.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Gg
    76.60.-k
    76.60.Lz
    68.35.Dv
    68.55.Ln
    Opis:
    Series of lutetium doped yttrium iron garnet films is studied by means of $\text{}^{57}Fe$ nuclear magnetic resonance. Satellite spectral lines are resolved and identified in the spectra and concentrations of lutetium in dodecahedral sites as well as yttrium/lutetium antisite defects in octahedral sites are estimated. Compared to yttrium, lutetium cations are found to have stronger disposition towards creating the antisite defects.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 846-847
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Tuned Probehead for NMR Spectroscopy in Magnetically Ordered Materials
    Autorzy:
    Sedlák, B.
    Kouřil, K.
    Chlan, V.
    Řezníček, R.
    Křišťan, P.
    Pfeffer, M.
    Englich, J.
    Štěpánková, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1534619.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    07.57.Pt
    76.60.-k
    76.60.Lz
    Opis:
    This work describes the design of a tuned NMR probehead that was developed for measurement of very broad spectra in fully impedance matched mode. The probehead is constructed as an insert of continuous flow cryostat to allow operation down to helium temperatures. Properties of the probehead are demonstrated on $\text{}^{57}Fe$ NMR in magnetic oxide with spinel structure.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 924-925
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Distribution of Zn in Magnetoelectric Y-Type Hexaferrite
    Autorzy:
    Kouřil, K.
    Chlan, V.
    Štěpánková, H.
    Telfah, A.
    Novák, P.
    Knížek, K.
    Hiraoka, Y.
    Kimura, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/1506927.pdf
    Data publikacji:
    2010-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.05.Qr
    75.85.+t
    75.50.Gg
    31.15.E-
    Opis:
    We employ $\text{}^{67}Zn$ NMR to study distribution of $Zn^{2+}$ in cationic sites of magnetoelectric Y-type hexaferrite single crystal, $Ba_{0.5} Sr_{1.5} Zn_2 Fe_{12} O_{22}$. The experimental data are interpreted by comparison with NMR spectra simulated from ab initio calculated hyperfine parameters.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 5; 732-733
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nuclear Magnetic Resonance in Hexaferrite/Maghemite Composite Nanoparticles
    Autorzy:
    Křišťan, P.
    Hondlík, O.
    Štěpánková, H.
    Chlan, V.
    Kouřil, K.
    Řezníček, R.
    Pollert, E.
    Veverka, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1386884.pdf
    Data publikacji:
    2015-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.60.-k
    75.50.Gg
    75.50.Tt
    75.47.Lx
    61.66.Fn
    Opis:
    Due to their bio-compatibility and non-toxicity, ferrimagnetic iron oxides are suitable for various medical applications. In the case of hyperthermia, the promising approach how to reach desired magnetic properties is to combine more phases into a composite material. A series of samples containing maghemite and M-hexaferrite was prepared by sol-gel method with subsequent thermal treatment where annealing temperature and time were varied. The samples were characterized by X-ray diffraction. In this paper we focused mainly on application of nuclear magnetic resonance spectroscopy to investigate these strongly inhomogeneous nanoparticle composites. Frequency-swept ⁵⁷Fe NMR spectra of nanoparticle samples were measured in a zero external magnetic field at 4.2 K. Utilizing differences in optimal excitation field strengths and in relaxation times, we were able to resolve NMR signal assigned to hexagonal ferrite of M-phase from signal which showed features attributed to maghemite.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 2; 514-516
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Cluster Superconductivity in the Magnetoelectric $Pb(Fe_{1//2}Sb_{1//2})O_3$ Ceramics
    Autorzy:
    Laguta, V.
    Marysko, M.
    Stephanovich, V.
    Raevsky, I.
    Olekhnovich, N.
    Pushkarev, A.
    Radyush, Yu.
    Raevskaya, S.
    Kuzian, R.
    Chlan, V.
    Štěpánková, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398326.pdf
    Data publikacji:
    2017-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    Multiferroics
    Superconductivity
    magnetic susceptibility
    Opis:
    We report the observation of cluster (local) superconductivity in the magnetoelectric $Pb(Fe_{1//2}Sb_{1//2})O_3$ ceramics prepared at a hydrostatic pressure of 6 GPa and temperatures 1200-1800 K to stabilize the perovskite phase. The superconductivity is manifested by an abrupt drop of the magnetic susceptibility at the critical temperature $T_{c}$ ≈7 K. Both the magnitude of this drop and $T_{c}$ decrease with magnetic field increase. Similarly, the low-field paramagnetic absorption measured by EPR spectrometer drops significantly below $T_{c}$ as well. The observed effects and their critical magnetic field dependence are interpreted as manifestation of the superconductivity and the Meissner effect in metallic Pb nanoclusters existing in the ceramics. Their volume fraction and average size were estimated as 0.1-0.2% and 140-150 nm, respectively. The superconductivity related effects disappear after oxidizing annealing of the ceramics.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 6; 1534-1539
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-11 z 11

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies