Temat: 74.40.+k - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Noise Anisotropy in $YBa_2Cu_3O_{7-δ}$ Thin Films
Autorzy:: Jung, G.
Camerlingo, C.
Zilber, E.
Powiązania:: https://bibliotekanauki.pl/articles/1810289.pdf
Data publikacji:: 2009-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.40.+k
74.78.-w
Opis:: Anisotropy of voltage noise in $YBa_2Cu_3O_{7-δ}$ thin films was investigated using (103)/(013) oriented films. Normalized noise in the normal state does not depend on the direction of current flow, while in the superconducting state the noise is anisotropic. The difference stems from different origins of noise. Normal state noise is due to random motion of charge carriers while in the superconducting state it arises from fluctuations of density and/or velocity of flux vortices.
Źródło:: Acta Physica Polonica A; 2009, 115, 1; 69-72
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Scattering Processes of Normal and Fluctuating Carriers in ReBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ (Re = Y, Ho) Single Crystals with Unidirectional Twin Boundaries
Autorzy:: Vovk, R. V.
Obolenskii, M. A.
Bondarenko, A. V.
Goulatis, I. I.
Levy, M. R.
Chroneos, A.
Powiązania:: https://bibliotekanauki.pl/articles/2047234.pdf
Data publikacji:: 2007-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.20.Eh
72.10.-d
74.40.+k
74.72.-h
Opis:: The effect of twin boundaries on the normal and fluctuating conductivity of ReBaCuO (Re = Y, Ho) single crystals was investigated. The results indicate that the Lawrence-Doniach theoretical model describes adequately the temperature dependence of the excess conductivity. The twin boundaries are efficient scattering centers for normal and fluctuating carriers. The derived values of the coherence length perpendicular to the ab-planeξ$\text{}_{c}$(0) are in good agreement with those obtained from magnetic measurements for stoichiometric YBaCuO crystals.
Źródło:: Acta Physica Polonica A; 2007, 111, 1; 123-128
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Excess Conductivity of Y$\text{}_{0.95}$Pr$\text{}_{0.05}$Ba$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ Single Crystals
Autorzy:: Vovk, R. V.
Obolenskii, M. A.
Bondarenko, A. V.
Goulatis, I. L.
Chroneos, A.
Powiązania:: https://bibliotekanauki.pl/articles/2047236.pdf
Data publikacji:: 2007-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.20.Eh
72.10.-d
74.40.+k
74.72.-h
Opis:: In this work we investigate the conductivity in the basis plane of YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ and Y$\text{}_{1-z}$Pr$\text{}_{z}$Ba$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ single crystals with a system of one-direction twin boundaries. The Pr dopants behave as efficient scattering centers of normal and fluctuating carriers. For this a slight doping with praseodymium (till z≈0.05) results in a significant narrowing of the temperature interval in which the pseudo-gap regime is realized in the ab-plane of YBaCuO single crystals.
Źródło:: Acta Physica Polonica A; 2007, 111, 1; 129-133
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Localization Effects in GaN/AlGaN Quantum Well - Photoluminescence Studies
Autorzy:: Chwalisz, B.
Wysmołek, A.
Bożek, R.
Korona, K. P.
Stępniewski, R.
Knap, W.
Pakuła, K.
Baranowski, J. M.
Grandjean, N.
Massies, J.
Prystawko, P.
Grzegory, I.
Powiązania:: https://bibliotekanauki.pl/articles/2036024.pdf
Data publikacji:: 2003-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.55.Cr
73.20.-r
73.21.-b
74.40.+k
Opis:: Exciton localization in GaN/AlGaN quantum well structures is studied by photoluminescence. An anomalous temperature behavior of the photoluminescence from the quantum well is observed. With increasing temperature the energy position of the excitonic emission line first decreases up to 20 K, then increases, reaching a maximum around 90 K, and then decreases again in the higher temperature range. The observed behavior is discussed in terms of localization at the interface potential fluctuations. It is argued that the temperature activated migration and subsequent release of the excitons from traps that occurs between 20 K and 90 K are responsible for the observed S-like shape of the energy dependence. The obtained results allow a direct characterization of the energy fluctuations present in GaN/AlGaN quantum wells grown by different techniques.
Źródło:: Acta Physica Polonica A; 2003, 103, 6; 573-578
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Influence of Well-Width Fluctuations on the Electronic Structure of GaN/Al$\text{}_{x}$Ga$\text{}_{1-x}$N Multiquantum Wells with Graded Interfaces
Autorzy:: Valcheva, E.
Dimitrov, S.
Monemar, B.
Haratizadeh, H.
Persson, P.O.A.
Amano, H.
Akasaki, I.
Powiązania:: https://bibliotekanauki.pl/articles/2047708.pdf
Data publikacji:: 2007-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.55.Cr
73.20.-r
73.21.-b
74.40.+k
Opis:: Experimental and computation results based on chemical composition assessment of metal-organic chemical vapour deposition grown undoped GaN/Al$\text{}_{x}$Ga$\text{}_{1-x}$N multiquantum well structures in the low composition limit of x = 0.07 and wide wells demonstrate composition fluctuations in the barrier layers which lead to large-scale nonuniformities and inequivalence of the different wells. As a consequence the experimental photoluminescence spectra at low temperature show a double peak structure indicative of well-width fluctuations by one lattice parameter (2 monolayers).
Źródło:: Acta Physica Polonica A; 2007, 112, 2; 395-400
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: Influence of Pressure on the Magnetic Response of the Low-Dimensional Quantum Magnet Cu(H₂O)₂(C₂H₈N₂)SO₄
Autorzy:: Peprah, M.
VanGennep, D.
Blasiola, B.
Quintero, P.
Tarasenko, R.
Xia, J.
Hamlin, J.
Meisel, M.
Orendáčová, A.
Powiązania:: https://bibliotekanauki.pl/articles/1030267.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Cx
75.50.Ee
74.62.Fj
07.35.+k
Opis:: The influence of pressure on the low-dimensional molecular magnet Cu(H₂O)₂(en)SO₄ (en = ethylenediamine = C₂H₈N₂) has theoretically been shown to affect the exchange interactions of the material. Herein, the results of an experimental study of hydrostatic pressure effects on the temperature dependence of the magnetization are reported. Using two different pressure cells, the magnetization measurements were performed between 2 K and 9.6 K with pressures ranging from ambient to 5.0 GPa. The data preliminarily suggest the presence of a shift in the magnetization peak of the material at the lowest temperatures and at the highest applied pressures. These data serve as a guide for future experimental work employing pressure to study this intriguing system.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 901-903
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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