Autor: Popovic, M. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Optical Characterization of Graphene and Highly Oriented Pyrolytic Graphite
Autorzy:: Kostić, R.
Mirić, M.
Radić, T.
Radović, M.
Gajić, R.
Popović, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1795772.pdf
Data publikacji:: 2009-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 63.20.D-
78.67.Wj
81.05.U-
Opis:: We present a symmetry analysis of allowed infrared and Raman modes in graphene and highly oriented pyrolytic graphite. Surface structure for highly oriented pyrolytic graphite is examined using atomic force microscopy. As experimental tools, we used infrared spectroscopic ellipsometry in order to investigate the pseudodielectric function of highly oriented pyrolytic graphite in the mid-infrared range (500-7000 $cm^{-1}$) and Raman spectroscopy to investigate the influence of layers number decrease. As a result, we propose a method for an experimental verification of graphene.
Źródło:: Acta Physica Polonica A; 2009, 116, 4; 718-721
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Hydrothermal Synthesis of $CeO_{2}$ and $Ce_{0.9}Fe_{0.1}O_{2}$ Nanocrystals
Autorzy:: Radović, M.
Dohčević-Mitrović, Z.
Golubović, A.
Matović, B.
Šćepanović, M.
Popović, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1795617.pdf
Data publikacji:: 2009-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.16.Be
61.05.C-
78.30.-j
78.67.Bf
Opis:: Pure and 10 mol% $Fe^{3+}$ doped $CeO_2$ nanocrystals were synthesized by hydrothermal method using two different basic solutions ($NH_4OH$ and NaOH). All the samples were calcinated at 140°C and 200°C. The characterization of crystalline structure, vibrational and optical properties was performed using X-ray diffraction, Raman spectroscopy and spectroscopic ellipsometry. The obtained results showed that the Fe-doped samples are solid solutions with different size of nanocrystals, very dependent on the synthesis temperature and type of basic solution. The Raman measurements demonstrated electron molecular vibrational coupling and increase of oxygen vacancy concentration whereas doping provokes a small decrease of optical absorption edge in comparison with pure ceria.
Źródło:: Acta Physica Polonica A; 2009, 116, 4; 614-617
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Effect of $Fe^{2+} (Fe^{3+})$ Doping on Structural Properties οf $CeO_2$ Nanocrystals
Autorzy:: Radović, M.
Dohčević-Mitrović, Z.
Paunović, N.
Šćepanović, M.
Matović, B.
Popović, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1807838.pdf
Data publikacji:: 2009-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.72.uj
78.30.-j
75.50.Tt
Opis:: We have measured the Raman scattering and magnetization of pure and $Fe^{2+}(Fe^{3+})$ doped $CeO_2$ nanopowders at room temperature. The Raman scattering spectra revealed the existence of $CeO_2$ fluorite cubic structure for all investigated samples. The Raman active mode at about 600 $cm^{-1}$, seen in all samples, can be ascribed to the $CeO_2$ intrinsic oxygen vacancies. Additional Raman modes at 720 $cm^{-1}$, 1320 $cm^{-1}$ and 1600 $cm^{-1}$, which appear in the spectra of doped samples, can be assigned to maghemite $(γ-Fe_2O_3)$ cation deficient structure, to $2ω_{LO}$ IR-allowed overtone and two magnon structure, respectively. This implies that our powders are composed of mixed valence states and have defective structure. Presence of oxygen defect states and magnetic ions can be responsible for the observed ferromagnetism at room temperature in both pure and Fe doped samples.
Źródło:: Acta Physica Polonica A; 2009, 116, 1; 84-87
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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