Wszystkie pola: Phonons - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Infrared active phonons and optical band gap in multiferroic GdMnO₃ studied by infrared and UV-visible spectroscopy
Autorzy:: Bukhari, S.
Ahmad, J.
Powiązania:: https://bibliotekanauki.pl/articles/1075504.pdf
Data publikacji:: 2016-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 63.20.-e
78.20.-e
72.20.-i
73.20.Mf
Opis:: Optical properties of multiferroic GdMnO₃ synthesized by sol-gel method have been investigated by measuring the infrared reflectivity and UV-visible absorption spectra. The infrared reflectivity spectrum of polycrystalline GdMnO₃ in the frequency range 30-7500 cm^{-1} at room temperature contains several phonon modes. The resonant frequency of observed infrared active phonon modes is found comparable with theoretically predicted results. Mean Born effective charges are calculated and discussed in view of the origin of ferroelectricity in GdMnO₃. Three strong absorption peaks observed in the UV-visible spectrum are attributed to the Mn (3d)-electron transitions. The optical band gap ≈1.2 eV is estimated from UV-visible absorption spectrum using Tauc's relation. GdMnO₃ seems to behave like an indirect gap semiconductor.
Źródło:: Acta Physica Polonica A; 2016, 129, 1; 43-48
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Polar Phonons in Relaxor Ferroelectric 0.2PSN-0.4PMN-0.4PZN
Autorzy:: Macutkevič, J.
Kamba, S.
Pashkin, A.
Banys, J.
Bormanis, K.
Sternberg, A.
Powiązania:: https://bibliotekanauki.pl/articles/1813209.pdf
Data publikacji:: 2008-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.30.-j
63.20.-e
71.55.Jv
Opis:: Relaxor ferroelectrics $0.2PbSc_{1//2}Nb_{1//2}O_3-0.4PbMg_{1//3}Nb_{2//3}O_3-0.4PbZn_{1//3}Nb_{2//3}O_3$ ceramics were studied by means of the Fourier transform infrared reflection and THz transmission spectroscopy in the temperature range of 20-500 K. On heating from low temperatures, the $A_1$ component of the strongly split $TO_1$ mode softens towards the Burns temperature, but the softening ceases near 400 K, which could be a signature of polar cluster percolation temperature.
Źródło:: Acta Physica Polonica A; 2008, 113, 3; 879-882
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Raman Piezospectroscopy of Phonons in Bulk 6H-SiC
Autorzy:: Grodecki, K.
Wysmołek, A.
Stępniewski, R.
Baranowski, J.
Hofman, W.
Tymicki, E.
Grasza, K.
Powiązania:: https://bibliotekanauki.pl/articles/1791360.pdf
Data publikacji:: 2009-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 62.50.-p
42.65.Dr
63.20.-e
78.30.-j
Opis:: Raman piezospectroscopy of high quality 6H-SiC crystals is presented. The crystals used in experiments were grown by the seeded physical vapor transport method. Uniaxial stress up to 0.9 MPa, obtained using a spring apparatus, was applied along [11-20] and [10-10] directions. It was found that the application of uniaxial stress led to different energy shifts of the observed phonon excitations in the investigated 6H-SiC crystals. The obtained pressure coefficients vary in the range 0.98-5.5 $cm^{-1}$ $GPa^{-1}$ for different transverse optical phonon modes. For longitudinal optic phonon modes pressure coefficients in the range 1.6-3.6 $cm^{-1}$ $GPa^{-1}$ were found. The data obtained could be useful in evaluation of local strain fields in SiC based structures and devices including epitaxial graphene.
Źródło:: Acta Physica Polonica A; 2009, 116, 5; 947-949
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Raman Scattering by Phonons and Magnons in MBE-Grown Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Layers
Autorzy:: Szuszkiewicz, W.
Jouanne, M.
Dynowska, E.
Janik, E.
Karczewskl, G.
Wojtowicz, T.
Kossut, J.
Powiązania:: https://bibliotekanauki.pl/articles/1934042.pdf
Data publikacji:: 1995-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Ds
63.20.-e
78.30.Fs
Opis:: Collective excitations have been analyzed for Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te epilayers (0.66 ≤ x ≤ 1) by the Raman scattering studies performed at temperatures from 7 K to 295 K. Apart from the lattice optical modes magnetic excitations (magnons) were observed at sufficiently low temperatures.
Źródło:: Acta Physica Polonica A; 1995, 88, 5; 941-944
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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