Informacja

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

Wyszukujesz frazę "Kim-Ngan, N." wg kryterium: Autor


Wyświetlanie 1-10 z 10
Tytuł:
Oxygen Emissions from Single-Crystalline Fe$\text{}_{3}$O$\text{}_{4}$ Surfaces Induced by Low-Energy Ion Bombardments
Autorzy:
Kim-Ngan, N.-T. H.
Soszka, W.
Powiązania:
https://bibliotekanauki.pl/articles/2046830.pdf
Data publikacji:
2006-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.35.-p
61.18.Bn
Opis:
Negative-charged ion energy spectra of the Fe$\text{}_{3}$O$\text{}_{4}$ (001) and (111) surface revealed large peaks attributed to the O$\text{}^{-}$ recoils from a binary collision. Under Ar$\text{}^{+}$ ion bombardments such an emission was largely affected by the screening effect of the Fe ions. A distinguished peak related to the O$\text{}^{+}$ recoil ions was observed under Ne$\text{}^{+}$ ion bombardments, while such a peak was merged into the high background in the case of Ar$\text{}^{+}$ ion ones. A weak effect from the Verwey transition was found on oxygen emissions. For the (111) surface a small peak characteristic of the O$\text{}^{+}$ recoils from double collisions appeared in the energy spectra around 140-170 K and a minimum was observed in both R$\text{}^{+}$(T) and R$\text{}^{-}$(T) curves under 6 keV Ne$\text{}^{+}$ ion beam.
Źródło:
Acta Physica Polonica A; 2006, 109, 6; 715-721
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scanning Tunneling Spectra and Low Energy Ion Scattering Studies of the Verwey Transition in MBE Fe$\text{}_{3}$O$\text{}_{4}$ (100) Thin Film
Autorzy:
Kim-Ngan, N.-T. H.
Soszka, W.
Hietschold, M.
Powiązania:
https://bibliotekanauki.pl/articles/2024029.pdf
Data publikacji:
2001-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.16.Ch
61.18.Bn
71.30.+h
Opis:
The (100) surface of magnetite Fe$\text{}_{3}$O$\text{}_{4}$ thin film was studied by a UHV low-temperature scanning tunneling microscope and by an ion scattering spectroscopy. The tunneling spectra revealed a widening of the gap with decreasing temperature, which may be related to the metal-insulator phase transition in this material. A strong effect of this phase transition on ion scattering from such a surface was observed. The temperature dependence of the scattered ion yield, R$\text{}^{+}$(T), revealed two minima at around 100 K and at 125 K under Ne$\text{}^{+}$ bombardment with the primary energy up to 6 keV. The disappearance of the high-temperature minimum at a bombarding energy of 6.5 keV gave a further evidence for the ion velocity dependence of the character of the R$\text{}^{+}$(T) curve, which has been first observed for a MBE Fe$\text{}_{3}$O$\text{}_{4}$ (111) film surface.
Źródło:
Acta Physica Polonica A; 2001, 99, 2; 267-276
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecule dissociation at the Fe3O4 (001) surface
Autorzy:
Kim-Ngan, N.-T. H.
Jagło, D.
Sitko, D.
Soszka, W.
Powiązania:
https://bibliotekanauki.pl/articles/411955.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Magnetite surface
low energy ion scattering
molecule dissociation
Opis:
The molecular dissociation at the single-crystalline Fe3O4 (001) surface has been investigated using the diatomic H+2 , D+2 and N+2 molecules in the energy range of 3�{8 keV and in the temperature range of 90 K�{300 K. The single collision of ions released from dissociation with the surface atoms was observed only for the N2+ molecules. The detail analysis confirmed that for the light molecules such as H2+ and D2+ the charge-transfer process dominate the interaction of a molecule with the magnetite surface. A large change in the scattered ion yields around the Verwey phase transition temperature was observed indicating a strong correlation between the molecule dissociation and the electronic state of the magnetite surface.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 2; 1-10
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interface Properties of Single and Bi-Layer $Fe_3O_4$ Films Grown on MgO(001) Studied by RBS and Channeling Experiments
Autorzy:
Kim-Ngan, N.
Balogh, A.
Brötz, J.
Zając, M.
Korecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1535628.pdf
Data publikacji:
2010-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.35.+a
68.35.Ct
68.35.Fx
68.47.Gh
Opis:
Series of $Fe_3O_4$/MgO(001) and $Fe_3O_4$/Fe/MgO(001) films (single- and bi-layer films, respectively) with a total layer thickness in the range of 20 ÷ 150 nm were investigated by the Rutherford backscattering spectrometry (2 MeV $He^{+}$ ion beam), by the Rutherford backscattering spectrometry channeling experiments (1.5 MeV $He^{+}$ ion beam). Depending on the layer thickness of each layer and the film geometry, a single Fe peak and/or a double-anomaly feature was revealed in the Rutherford backscattering spectra. For all films no magnesium presence in the surface layer was observed. For both single- and bi-layer films with a total layer thickness less than 60 nm only one minimum was observed in the channeling curves, while a double minimum was revealed for the bi-layer films with a larger thickness. X-ray reflectometry measurements have revealed that the film density is the same as that of the bulk one.
Źródło:
Acta Physica Polonica A; 2010, 118, 4; 570-575
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Amorphous 5f Ferromagnetic Hydrides $UH_{3}Mo_{x}$
Autorzy:
Tkach, I.
Kim-Ngan, N.
Maškova, S.
Andreev, A.
Matěj, Z.
Havela, L.
Powiązania:
https://bibliotekanauki.pl/articles/1369135.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Kj
75.50.Vv
72.15.Cz
Opis:
γ-U metal, stabilized down to room temperature in the bcc structure by Mo doping, can absorb hydrogen at high $H_{2}$ pressures only. The product is amorphous hydride $UH_{3}Mo_{x}$ analogous to $β-UH_{3}$. Such hydrides are ferromagnetic with high Curie temperatures (up to 200 K), enhanced with respect to $β-UH_{3}$. Magnetic moment of U also increases. Large disorder together with high anisotropy lead to a very high coercivity, reaching 4 T at low temperatures. As amorphization normally tends to suppress magnetic ordering of U compounds, such hydrides represent a new class of materials, amorphous U-based ferromagnets with relatively high Curie temperature.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 292-293
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconductivity in U-T Alloys (T = Mo, Pt, Nb, Zr) Stabilized in the Cubic γ-U Structure
Autorzy:
Sowa, S.
Kim-Ngan, N.
Krupska, M.
Paukov, M.
Tkach, I.
Havela, L.
Powiązania:
https://bibliotekanauki.pl/articles/1398594.pdf
Data publikacji:
2016-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
74.70.Ad
72.15.Cz
Opis:
Using ultrafast cooling (with the cooling rate up to 10⁶ K/s) helps to minimize the T-alloying concentration (T = Mo, Pt, Pd, Nb, Zr) necessary to retain the γ-U phase down to low temperatures. All investigated splat-cooled U-T alloys become superconducting with $T_{c}$ in the range of 0.61-2.11 K. The bulk character of superconductivity can be concluded for some of the splats when comparing the specific-heat anomaly at $T_{c}$ with the BCS theory prediction.
Źródło:
Acta Physica Polonica A; 2016, 130, 2; 521-526
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Investigations of Selected Materials by Low-Energy Ion Scattering Technique
Autorzy:
Goc-Jagło, D.
Sitko, D.
Jagło, G.
Kim-Ngan, N.-T. H.
Soszka, W.
Powiązania:
https://bibliotekanauki.pl/articles/2047339.pdf
Data publikacji:
2007-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.35.Rh
71.20.Be
71.20.Eh
77.80.Bh
Opis:
Surfaces of three selected materials were investigated by means of low-energy ion-scattering technique: (1) the magnetite (Fe$\text{}_{3}$O$\text{}_{4}$) exhibiting the so-called Verwey transition (T$\text{}_{V}$(bulk)=125 K) accompanied by a small cubic-monoclinic crystal distortion, (2) the intermetallic compound NdMn$\text{}_{2}$ undergoing an antiferromagnetic-paramagnetic phase transition (T$\text{}_{N}$=104 K) accompanied by a large crystal distortion with a volume change of 1%, and (3) the typical insulator BaTiO$\text{}_{3}$ with two structural transitions below 300 K. The primary energy of the (Ne$\text{}^{+}$, Ar$\text{}^{+}$) ion beam was in the range of 4-8 keV, and the low-energy ion-scattering spectra were collected in the temperature range of 85-300 K. A large influence from the Verwey transition on the neutralization and re-ionization of scattered ions from magnetite surface was observed, while no visible change at the magnetic phase transition in NdMn$\text{}_{2}$ was revealed in the low-energy ion-scattering spectra. A strong dependence of the characteristics of the low-energy ion-scattering spectra on the irradiated time was observed for BaTiO$\text{}_{3}$ indicating that this surface was heavily charged by ion bombardments.
Źródło:
Acta Physica Polonica A; 2007, 111, 5; 763-771
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic States of $UNi_2$ from Photoemission Spectroscopy
Autorzy:
Zalecki, R.
Kołodziejczyk, A.
Kim-Ngan, N.
Adamska, A.
Kowalczyk, A.
Toliński, T.
Mihalik, M.
Powiązania:
https://bibliotekanauki.pl/articles/1813761.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Lp
79.60.Bm
71.15.Ap
Opis:
We measured the angle-resolved ultraviolet and X-ray photoemission spectra of $UNi_2$ single crystal. The valence band angle-resolved ultraviolet photoemission spectra were compared to the accessible band structure calculations. For $UNi_2$ the lowest binding energy strong emission at about -0.1 eV comes from U 5f states and overlaps with the Fermi edge. A small feature at -0.6 eV was ascribed also to U 5f electrons with more localised character. The higher-energy two-peak structure at about -1.2 eV and -2.1 eV comes from Ni 3d states. X-ray photoemission spectroscopy shows the standard two-line spin-orbit splitting of the Ni 2p states and of the U 4f states. Some hybridisation of the Ni 3d and U 5f state was observed in the spectra. The pronounced satellites to the Ni 2p and 3p states, associated with the on-site Coulomb repulsion and other electron correlation energies, were observed.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 407-412
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Ti, V and Their Oxides-Based Thin Films in the Search for Hydrogen Storage Materials
Autorzy:
Tarnawski, Z.
Zakrzewska, K.
Kim-Ngan, N.-T.
Krupska, M.
Sowa, S.
Drogowska, K.
Havela, L.
Balogh, A.
Powiązania:
https://bibliotekanauki.pl/articles/1401913.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Cd
68.49.-h
61.05.C-
68.60.-p
Opis:
Thin film series consisting of Ti, V, TiO₂ and V₂O₅ layer with different layer geometries, sequences and thicknesses have been prepared by the sputtering technique. The hydrogen depth profile of selected films upon hydrogen charging at 1 bar and/or hydrogenation at pressure up to 102 bar was determined by using secondary ion mass spectrometry and nuclear reaction analysis using a N-15 beam. The highest hydrogen storage with a concentration up to 50 at.% was found in the pure Ti and Ti-contained layer, while it amounts to around 30% in the metallic Ti-V-Ni layer. Hydrogen can diffuse through the TiO₂ layer without accumulation, but can be stored in the VO₂ layer in some cases. Hydrogen can remove the preferential Ti orientation in the films and induce a complete transition of V₂O₅ into VO₂ in the films.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 431-439
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific Heat of RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ and RBaSrCu$\text{}_{3}$O$\text{}_{7-x}$ Compounds (R = Sm, Dy, Er)
Autorzy:
Tarnawski, Z.
Kim-Ngan, N.-T. H.
Wang, X. Z.
Duijn, V. H. M.
Franse, J. J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1968860.pdf
Data publikacji:
1998-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
75.40.-s
Opis:
The low-temperature specific-heat C(T) data of high-T$\text{}_{c}$ superconductors RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$(R123O$\text{}_{7-x}$) were reviewed. A discussion of the C(T) data obtained on single-crystalline samples of Er123O$\text{}_{7-x}$ and Sm123O$\text{}_{7-x}$ compounds in applied magnetic fields for better evaluation of the crystal-electric-field parameters is given. The C(T) measurements of Sr-substituted compounds RBaSrCu$\text{}_{3}$O$\text{}_{7}$ revealed the λ-type of peak related to the antiferromagnetic order at 1.2 K and 0.6 K respectively for Dy- and Er-compounds. The magnetic singlet ground state in these compounds is produced by weak exchange interactions of -0.05 T/μ$\text{}_{B}$ and -0.035 T/μ$\text{}_{B}$, respectively. For Nd- and Sm-compounds, only a broad anomaly around 0.6 K was observed which is well fitted with a Schottky-type anomaly with an energy splitting of 1.4 K.
Źródło:
Acta Physica Polonica A; 1998, 93, 3; 513-522
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

    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