Informacja

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

Wyszukujesz frazę "Dietl, T." wg kryterium: Autor


Wyświetlanie 1-36 z 36
Tytuł:
Why Ferromagnetic Semiconductors?
Autorzy:
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2030392.pdf
Data publikacji:
2001-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
72.25.Dc
75.30.Hx
85.75.-d
Opis:
Rapid development of information technologies originates from the exponential increase in the density of information that can be processed, stored, and transferred by the unit area of relevant devices. There is, however, a growing amount of evidences that the progress achieved in this way approaches its limits. Various novel ideas put forward to circumvent barriers ahead are described. Particular attention is paid to those concepts which propose to exploit electron or nuclear spins as the information carriers. Here, ferromagnetic semiconductors of III-V or II-VI compounds containing a sizable concentration of transition metals appear as outstanding spintronic materials.
Źródło:
Acta Physica Polonica A; 2001, 100, Supplement; 139-151
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
From Magnetic Polarons to Ferromagnetism
Autorzy:
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/1968985.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
75.70.Cn
78.55.Et
78.66.Hf
Opis:
A brief overview is given on selected effects of the exchange coupling between effective mass electrons and localized spins in II-VI semiconductors containing Mn ions. In the case of a carrier or exciton trapped by an impurity or defect, the exchange interaction leads to zero-field spin-splitting. The current theory of such complexes, known as bound magnetic polarons, describes correctly their spectroscopic and thermodynamic properties as well as their formation dynamics. At the same time, a free magnetic polaron - a delocalized carrier accompanied by a traveling cloud of polarized spins - is not expected to exist for the actual values of the coupling constants. However, hole scattering by thermodynamic and static fluctuations is shown to affect significantly its energy. For a strong coupling, the corresponding renormalization has to be described by a non-perturbative approach. Finally, the influence of the carrier liquid upon the Mn spins is discussed. Here, either optical pumping or p-type doping may lead to a ferromagnetic order, both in bulk and layered structures. Because of a long-range character of the carrier mediated interactions, this ordering is not destroyed by the fluctuations, even in the reduced dimensionality systems.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 111-123
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Magnetic Impurities upon Universal conductance Fluctuations
Autorzy:
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/1953174.pdf
Data publikacji:
1997-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
72.15.Rn
73.61.Ga
73.20.Fz
Opis:
Mesoscopic phenomena in quantum structures which incorporate magnetic impurities with localized spins may exhibit a number of novel features driven by spin-disorder scattering, exchange spin-splitting of electron bands, and the formation of bound magnetic polarons. After brief information on these effects, their influence on universal conductance fluctuations as well as on low frequency noise and quantum localization is presented. Millikelvin investigations of diffusive charge transport, which have been carried out for submicron wires of n$\text{}^{+}$-Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te epilayers, are reviewed in some details. These studies have provided information on the significance of spin-disorder scattering in semiconductors and put into the evidence a new driving mechanism of the magnetoconductance fluctuations - the redistribution of the electrons between energy levels of the system, induced by the giant s-d exchange spin-splitting. Important implications of these findings for previous interpretations of spin effects in semiconductor and metal nanostructures are discussed.
Źródło:
Acta Physica Polonica A; 1997, 91, 1; 161-171
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Temperature Ferromagnetism and Nano-Scale Phase Separations in Diluted Magnetic Semiconductors and Oxides
Autorzy:
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2047208.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
Opis:
In this paper the present understanding of the origin of ferromagnetic response that has been detected in a number of diluted magnetic semiconductors and diluted magnetic oxides at room temperature is outlined. It is argued that in these systems, owing to a typically small solubility of magnetic ions, crystallographic or chemical phase separation into regions with a large and a small concentration of magnetic component takes place. The ferromagnetic signatures then come from the regions with a large concentration of magnetic ions, which show non-zero spontaneous magnetization up to the blocking temperature, whose magnitude is proportional to the nanocrystal volume and magnetic anisotropy. Novel methods enabling a control of nano-assembling of magnetic nanocrystals in non-conducting matrices as well as possible functionalities of these spatially modulated magnetic systems are described. We also discuss phase separations into paramagnetic and ferromagnetic regions, which are driven by the Anderson-Mott localization and/or competing ferromagnetic and antiferromagnetic interactions. Finally, the question whether the high temperature ferromagnetism is possible in materials without magnetic ions is addressed.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 27-46
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
s-p-d-f Exchange Interactions in Mn and Eu Based IV-VI Semimagnetic Semiconductors
Autorzy:
Dietl, T.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1921647.pdf
Data publikacji:
1992-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Gm
Opis:
We evaluated exchange integrals which describe the spin dependent coupling between effective mass electrons and localized spins in the IV-VI semi-magnetic semiconductors taking into account contributions from the direct Coulomb exchange as well as from the hybridization between band states and magnetic shells. The obtained constants compare favorably with the experimental values for both the Mn- and the Eu-based compounds. We also discuss some peculiarities of IV-VI semimagnetic semiconductors, which may render the virtual-crystal approximation invalid.
Źródło:
Acta Physica Polonica A; 1992, 82, 5; 729-732
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Ferromagnetic p-d Exchange in Diluted Magnetic Semiconductors
Autorzy:
Blinowski, J.
Dietl, T.
Kacman, P.
Powiązania:
https://bibliotekanauki.pl/articles/1921558.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.-m
71.70.-d
Opis:
The antiferromagnetic type of the interaction between the Γ$\text{}_{8}$-band electrons and the Mn$\text{}^{2+}$ ions in A$\text{}^{II}$B$\text{}^{IV}$ diluted magnetic semiconductors has been explained by invoking the p-d hybridization mechanism. In this paper it is shown that for particular electronic configurations of the magnetic ions in diluted magnetic semiconductors the p-d hybridization can lead to a ferromagnetic interaction between the valence-band electrons and the localized spins. This happens when all the one-electron d-orbitals which hybridize with p-band states are empty (e.g., as in Sc$\text{}^{2+}$ and Ti$\text{}^{2+}$ ions). The appropriate p-d Hamiltonian is derived and the ferromagnetic exchange constants are evaluated.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 641-644
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial Correlation of Impurity Charges Induced by Coulomb Interactions - Application to DX Centers in GaAs
Autorzy:
Kossut, J.
Wilamowski, Z.
Dietl, T.
Świątek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1877485.pdf
Data publikacji:
1991-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.80.Ey
72.20.Dp
71.55.Eq
Opis:
The electron mobility enhancement observed in heavily doped GaAs under hydrostatic pressure is interpreted in terms of spatial correlation between the donor charges within partially occupied system of impurities induced by strong inter-donor Coulomb interaction. A simple analytic theory is given for both DX$\text{}^{0}$ and DX$\text{}^{-}$ models of the impurity state. The mobility is shown to increase together with pressure in both models. Estimates of the energy of the DX level are strongly perturbed by the inter-donor Coulomb interactions.
Źródło:
Acta Physica Polonica A; 1991, 79, 1; 49-58
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation Time of Magnetic Polarons
Autorzy:
Dietl, T.
Peyla, P.
Grieshaber, W.
Merle d'Aubigné, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1872800.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.47.+p
78.55.Et
75.50.Rr
Opis:
It is shown that non-scalar spin-spin interactions rather than spin-lattice coupling or spin diffusion control the dynamics of the magnetization formation visible in time-resolved luminescence and SQUID magnetometry.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 361-364
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Light-Controlled Transport in Doped Diluted Magnetic Semiconductors near Localization Boundary
Autorzy:
Głód, P.
Dietl, T.
Wojtowicz, T.
Sawicki, M.
Miotkowski, I.
Powiązania:
https://bibliotekanauki.pl/articles/1929694.pdf
Data publikacji:
1993-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.30.+h
75.50.Pp
72.40.+w
Opis:
We report milikelvin studies of light induced metastable changes of the conductivity of the In doped Cd$\text{}_{0.95}$Mn$\text{}_{0.05}$Te$\text{}_{0.97}$Se$\text{}_{0.03}$ crystals in the vicinity of the metal-insulator transition.
Źródło:
Acta Physica Polonica A; 1993, 84, 4; 657-660
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductivity Near the Metal-to-Insulator Transition in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Se:Sc
Autorzy:
Głód, P.
Sawicki, M.
Lenard, A.
Dietl, T.
Plesiewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/1887158.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.30.+h
71.55.Jv
Opis:
Earlier studies of transition metal impurities in II-VI compounds suggest that Sc acts as a resonant donor. We performed Hall effect and conductivity measurements of CdSe:Sc and Cd$\text{}_{0.95}$Mn$\text{}_{0.05}$Se:Sc. The results, particularly the critical concentration of the metal-to-insulator transition, turned out to be similar to those obtained previously for Cd$\text{}_{1-x}$Mn$\text{}_{x}$Se doped with hydrogenic-like impurities, such as In and Ga. Therefore, if the ground state of Sc impurity is indeed located above the bottom of the conduction band, our data demonstrate that the metal-to-insulator transition is primarily driven by the scattering, i.e. it corresponds to the Anderson localization.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 389-392
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of Two-Dimensional Electron Gas in LPE-Grown GaInAs-InP Heterostructures
Autorzy:
Fronc, K.
Grabecki, G.
Wróbel, J.
Dietl, T.
Gajewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1891365.pdf
Data publikacji:
1991-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Df
73.20.Dx
73.60.Br
Opis:
A series of GaInAs/InP heterostructures was grown by liquid phase epitaxy. The heterostructures were characterized by magnetotransport measurements carried out down to 1.8 K and up 10 T. The results demonstrate the existence of the high-mobility two-dimensional electron gas in the narrow-gap GaInAs as well as the presence of residual conductance through the InP buffer layer.
Źródło:
Acta Physica Polonica A; 1991, 80, 3; 449-452
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for Dimensional Effects in Spin-Glass Transition in Thin Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Multilayers
Autorzy:
Sawicki, M.
Dietl, T.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1943818.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Rr
75.50.Lk
75.30.Kz
75.50.-y
Opis:
SQUID magnetic measurements of CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te, x ≃ 0.5, multi-layers with different CdMnTe layer thickness w reveal the persistence of the spin-glass irreversibilities down to ≃ 16 Å thin layers, i.e., well beyond the previously postulated 40 Å as a quasi-2D threshold. The freezing temperature T$\text{}_{f}$ is found to be a monotonic function of w, and it obeys a scaling law T$\text{}_{f}$ ∝ w$\text{}^{a}$, with a 0.8 similar to that for canonical spin-glasses. Magnetic properties of all studied structures are found to be independent of the orientation of the magnetic field.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1038-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Bound Magnetic Polarons on Magnetic and Electrical Properties in Metallic n-Cd$\text{}_{0.95}$Mn$\text{}_{0.05}$Se
Autorzy:
Głód, P.
Sawicki, M.
Dietl, T.
Skośkiewicz, T.
Lenard, A.
Plesiewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/1931936.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.30.+h
71.38.+i
75.20.Hr
Opis:
Doping-induced contribution to the millikelvin magnetic susceptibility of Cd$\text{}_{0.95}$Mn$\text{}_{0.05}$Se:In has been found to undergo a maximum at n ≈ 2n$\text{}_{c}$, and to vanish for n ≥ 8n$\text{}_{c}$, where n$\text{}_{c}$ is the electron concentration corresponding to the metal-insulator transition. This confirms the presence, also in the metallic phase, of bound magnetic polarons. Their slow dynamics may account for hysteresis visible in our magnetoresistance data.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 173-175
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ferromagnetism in II-VI Based Semiconductor Structures
Autorzy:
Cibert, J.
Ferrand, D.
Tatarenko, S.
Wasiela, A.
Kossacki, P.
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2027470.pdf
Data publikacji:
2001-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.80.Ey
75.50.Pp
75.30.Hx
75.50.Dd
Opis:
The experimental results on carrier-induced ferromagnetic interaction in II-VI diluted magnetic semiconductors are shortly reviewed and analyzed in the light of the mean field approximation. We particularly take the point of view of the experimentalist to emphasize (i) points which are easily understood within this simple model (as the role of the detailed structure of the valence band) and hence should be incorporated into more sophisticated models, and (ii) points which are not taken into account in the mean field model (e.g., disorder effects) and hence call for more elaborate descriptions. We particularly discuss the case of a low carrier density, and show that the situation appears as experimentally very different in the highly disordered 3D layers and in the modulation doped 2D quantum wells.
Źródło:
Acta Physica Polonica A; 2001, 100, 2; 227-236
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for Dimensionality Crossover of Spin-Glass Freezing in Superlattices of Cd$\text{}_{0.50}$Mn$\text{}_{0.50}$Te/CdTe
Autorzy:
Sawicki, M.
Dietl, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Skośkiewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1952078.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.50.Rr
75.50.Lk
Opis:
SQUID measurements of the time decay of the thermoremanent magnetization (field-cooled in 1000 Oe) at long time scale, 10$\text{}^{2}$ < t < 10$\text{}^{5}$ s, are presented for MBE grown Cd$\text{}_{0.50}$Mn$\text{}_{0.50}$Te. We found that for both thin (32 Å) and thick (2500 Å) layers the spin-glass dynamics is characterized by a similar value of k = -(1/T$\text{}_{f}$)(dT$\text{}_{f}$/dlogt) > 0.05, indicating the absence of the phase transition at nonzero temperature under the experimental conditions.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 919-922
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Megagauss Cyclotron Resonance and Quantum Hall Effect of 2D Electron Gas in HgCdMnTe
Autorzy:
Grabecki, G.
Takeyama, S.
Dietl, T.
Takamasu, T.
Shimamotο, Y.
Miura, N.
Powiązania:
https://bibliotekanauki.pl/articles/1933749.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.25.Hc
73.50.Fq
73.20.Dx
73.40.Lq
Opis:
Two-dimensional electron gas adjacent to a grain boundary in bicrystal of narrow-gap semiconductor p- Hg$\text{}_{0.79}$Cd$\text{}_{0.19}$Mn$\text{}_{0.02}$Te has been studied under ultra strong impulse magnetic fields (up to 140 T). Both cyclotron resonance and quantum Hall effect are measured for the same samples. The values of the resonance fields point to strong nonparabolicity. A broadening of the line is interpreted in terms of an intersubband mixing that occurs for the upper Landau level. A steep increase in the linewidth in the field range 20-30 T, which coincides with a strong decrease in the Hall resistance is assigned to the field-induced metal-insulator transition in our system.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 731-734
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Ballistic Transport in Wires of n-PbTe
Autorzy:
Grabecki, G.
Wróbel, J.
Dietl, T.
Papis, E.
Kamińska, E.
Piotrowska, A.
Ueta, Y.
Sprinholtz, G.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1968110.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.-r
73.23.Ad
73.50.Dn
Opis:
We present results of magnetotransport studies on quantum wires of submicron PbTe epilayers, fabricated by means of electron beam lithography and dry etching. When the wire width is reduced down to 1 μm, the transition from diffusive to ballistic regime is observed. Effects associated with collimation and boundary scattering are found in the Hall, longitudinal, and van der Pauw magnetoresistance for wires and junctions in the shape of a cross.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 789-792
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron Localization in Sb-Doped Si/SiGe Superlattices
Autorzy:
Dietl, T.
Jaroszyński, J.
Sawicki, M.
Głód, P.
Wróbel, J.
Stöger, G.
Brunthaler, G.
Bauer, G.
Schäffler, F.
Powiązania:
https://bibliotekanauki.pl/articles/1933732.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.61.Cw
72.15.Rn
73.20.Fz
Opis:
Millikelvin studies of in-plane magnetoconductance in short period Si/Ge:Sb superlattices have been carried out in order to examine the effect of anisotropy on quantum localization. The field-induced metal-to-insulator transition has been observed, indicating the existence of extended states. This suggests that despite anisotropy as large as D $\text{}_{∥}$/D$\text{}_{⊥}$ ≈ 10$\text{}^{3}$ the system behaves as 3D in respect of localization by disorder.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 699-702
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precision of the Hall Quantization in Naturally Occurring Two-Dimensional System - HgCdMnTe Bicrystals
Autorzy:
Grabecki, G.
Wittlin, A.
Dietl, T.
Teunissen, P. A. A.
Wiegers, S. A. J.
Perenboom, J. A. A. J
Powiązania:
https://bibliotekanauki.pl/articles/1921658.pdf
Data publikacji:
1992-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.My
72.80.Ey
73.40.Lq
Opis:
New magnetoresistance measurements on naturally occurring inversion layers adjacent to grain boundaries in narrow gap diluted magnetic semiconductor HgCdMnTe (Eg ≤ 200 meV) have been performed. The magnetic fields up to 20 T simultaneously with millikelvine temperatures have been applied. Possible experimental factors affecting the quantum Hall effect in our system are discussed in detail.
Źródło:
Acta Physica Polonica A; 1992, 82, 5; 733-736
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductance Fluctuations in Microstructures of HgCdMnTe Bicrystals
Autorzy:
Grabecki, G.
Lenard, A.
Plesiewicz, W.
Jaroszyński, J.
Cieplak, Marek
Skośkiewicz, T.
Dietl, T.
Kamińska, E.
Piotrowska, A.
Bulka, B.
Powiązania:
https://bibliotekanauki.pl/articles/1890700.pdf
Data publikacji:
1991-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Lq
Opis:
Microscopic four-contact probes to semimagnetic HgCdMnTe grain-boundary inversion layers have been photolithographically patterned. Magnetoresistance measurements performed on these samples revealed aperiodic conductance fluctuations of the magnitude of the order of e$\text{}^{2}$/h. Quantitative analysis of both fluctuation amplitude and their mean period indicate that we have approached the mesoscopic regime in our system. This opens new possibilities in studies of spin-subsystem dynamics in semimagnetic semiconductors.
Źródło:
Acta Physica Polonica A; 1991, 80, 2; 307-310
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mesoscopic Phenomena in Microstructures of IV-VI Epilayers
Autorzy:
Grabecki, G.
Dietl, T.
Plesiewicz, W.
Lenard, A.
Skośkiewicz, T.
Kamińska, E.
Piotrowska, A.
Papis, E.
Frank, N.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1877113.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
Opis:
Magnetoresistance measurements of photolithographically patterned PbSe and Pb$\text{}_{1-y}$Mn$\text{}_{x}$Se microstructures were performed. Reproducible magnetoconductance fluctuations with the amplitude increasing with decreasing temperature were observed. Unexpectedly, these fluctuations contain a component periodic in the magnetic field, and their magnitude is greater than that expected from the current theory of the universal conductance fluctuations. Possible explanations are discussed.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 551-554
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductance Fluctuations in PbSe: Manifestation of Ballistic Transport in Macroscale?
Autorzy:
Grabecki, G.
Takeyama, S.
Adachi, S.
Takagi, Y.
Dietl, T.
Kamińska, E.
Piotrowska, A.
Papis, E.
Frank, N.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1933748.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
Opis:
Precise magnetoresistance measurements on microstructures of photolithographically patterned PbSe epilayers have been performed in the magnetic field range up to 17 Τ. Unusually large, reproducible magnetoconductance fluctuations have been observed. The fluctuation amplitude decreases exponentially with the magnetic field. A correlation magnetic field of the fluctuations corresponds to the Aharonov-Bohm effect which involves electron trajectories much smaller than the electron mean free path. This points strongly to the ballistic, not diffusive, origin of the observed phenomenon.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 727-730
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Hall Ferromagnet in Magnetically-Doped Quantum Wells
Autorzy:
Andrearczyk, T.
Jaroszyński, J.
Wróbel, J.
Karczewski, G.
Wojtowicz, T.
Papis, E.
Kamińska, E.
Piotrowska, A.
Popović, D.
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2036881.pdf
Data publikacji:
2003-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.43.Nq
72.25.Dc
73.61.Ga
75.50.Pp
Opis:
The article reviews our recent studies on quantum Hall ferromagnetism in diluted magnetic semiconductors. We carried out magnetoresistance studies on modulation-doped, gated heterostructures of (Cd,Mn)Te/(Cd,Mg)Te:I. We put into evidence the formation of Ising quantum Hall ferromagnet with Curie temperature T$\text{}_{C}$ as high as 2 K. Quantum Hall ferromagnetism is manifested by anomalous magnetoresistance maxima. Moreover, magnitude of these spikes depends dramatically on the history of the sample, shows hysteresis when either magnetic field or gate voltage are swept, stretched-exponential time evolution characteristic of glassy systems, and strong Barkhausen noise. Our study suggests that these metastabilities stem from the slow dynamics of ferromagnetic domains.
Źródło:
Acta Physica Polonica A; 2003, 104, 2; 93-102
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Characterization of Molecular Beam Epitaxy Grown $Cd_{1-x}$Mn$\text{}_{x}$Te Structures
Autorzy:
Sawicki, M.
Kolesnik, S.
Wojtowicz, T.
Karczewski, G.
Janik, E.
Kutrowski, M.
Żakrzewski, A.
Dynowska, E.
Dietl, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1931934.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.50.Rr
75.50.Ee
Opis:
The paper reports on the application of SQUID magnetometry to probe magnetic ion distribution in epilayers and at interfaces of diluted magnetic semiconductors. We present also new results on the possible influence of the magnetic confinement on the formation of the spin-glass phase, and on antiferromagnetic phase transition in zinc-blende MnTe.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 169-172
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties and Characterization of ALD Grown Dielectric Oxides for MIS Structures
Autorzy:
Gierałtowska, S.
Sztenkiel, D.
Guziewicz, E.
Godlewski, M.
Łuka, G.
Witkowski, B. S.
Wachnicki, Ł.
Łusakowska, E.
Dietl, T.
Sawicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/2048118.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Gh
77.55.-g
77.84.Bw
81.05.Ea
Opis:
We report on an extensive structural and electrical characterization of undergate dielectric oxide insulators Al$\text{}_{2}$O$\text{}_{3}$ and HfO$\text{}_{2}$ grown by atomic layer deposition. We elaborate the atomic layer deposition growth window for these oxides, finding that the 40-100 nm thick layers of both oxides exhibit fine surface flatness and required amorphous structure. These layers constitute a base for further metallic gate evaporation to complete the metal-insulator-semiconductor structure. Our best devices survive energizing up to ≈ 3 MV/cm at 77 K with the leakage current staying below the state-of-the-art level of 1 nA. At these conditions the displaced charge corresponds to a change of the sheet carrier density of 3 × 10$\text{}^{13}$ cm$\text{}^{-2}$, which promises an effective modulation of the micromagnetic properties in diluted ferromagnetic semiconductors.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 692-695
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of Ferromagnetism in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Based Quantum Wells
Autorzy:
Bertolini, M.
Boukari, H.
Ferrand, D.
Cibert, J.
Tatarenko, S.
Gilles, B.
Maślana, W.
Gaj, J. A.
Kossacki, P.
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2035587.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Hx
75.50.Dd
75.50.Pp
78.55.Et
Opis:
New structures aiming at controlling the ferromagnetic properties of diluted magnetic semiconductor quantum wells are presented. The carrier density is controlled by applying a voltage across a p-i-n diode. A new method, creating a 2D hole gas by adjusting the distance between the quantum well and surface, offers opportunities for a broader range of structures.
Źródło:
Acta Physica Polonica A; 2002, 102, 4-5; 603-608
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Second Harmonic Generation in Spin-Glass Microstructures and Fabrication of Microstructures in IV-VI Epilayers
Autorzy:
Grabecki, G.
Dietl, T.
Cieplak, Marek
Plesiewicz, W.
Lenard, A.
Skośkiewicz, T.
Kamińska, E.
Piotrowska, A.
Żarecka, R.
Springholz, G.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1929753.pdf
Data publikacji:
1993-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
Opis:
We studied magnetoconductance of two different mesoscopic systems: microregions containing two-dimensional electron gas adjacent to a grain-boundary plane in bicrystals of Hg$\text{}_{0.79}$Cd$\text{}_{0.19}$Mn$\text{}_{0.02}$Te and photolithographically patterned microstructures of Pb$\text{}_{1-x}$Mn$\text{}_{x}$Se. In both systems universal conductance fluctuations and generation of the second-harmonic voltage were observed at T ≤ 1 K. Moreover, in the former system the second harmonic signal exhibited distinct rise when the sample was cooled below the spin-glass freezing temperature (100 mK).
Źródło:
Acta Physica Polonica A; 1993, 84, 4; 781-784
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetization Steps in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Observed in Coherent Transport
Autorzy:
Jaroszyński, J.
Dietl, T.
Wróbel, J.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Maude, D. K.
van der Linden, P.
Portal, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/1968114.pdf
Data publikacji:
1997-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Rn
73.61.Ga
73.20.Fz
Opis:
Magnetoconductance measurements on submicron wires of n$\text{}^{+}$-Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te were carried out up to 27 T and down to 100 mK. The inverse correlation field of the universal conductance fluctuations is found to increase abruptly in the vicinity of the magnetization steps due to Mn pairs in CdMnTe. No such effect is observed in similar wires of CdTe. These findings support a recent model, according to which the correlation field of the universal conductance fluctuations in magnetic systems is inversely proportional to the magnetic susceptibility of the localized spins.
Źródło:
Acta Physica Polonica A; 1997, 92, 4; 797-800
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductance Fluctuations in Quantum Wires of n-CdTe and n-Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te
Autorzy:
Jaroszyński, J.
Wróbel, J.
Sawicki, M.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Dietl, T.
Kamińska, E.
Papis, E.
Barcz, A.
Piotrowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1934061.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Rn
73.61.Ga
73.20.Fz
Opis:
We present millikelvin studies of magnetoconductance in submicron wires of In-doped n$\text{}^{+}$-CdTe and n$\text{}^{+}$-Cd$\text{}_{0.99}$Mn$\text{}_{0.01}$Te epilayers. Weak-field magnetoresistance which arises from quantum localization as well as universal conductance fluctuations have been observed. The exchange coupling to magnetic impurities is shown to decrease the correlation field of the fluctuations. This novel effect is interpreted by invoking a new driving mechanism of the magnetoconductance fluctuations - the redistribution of the electrons between energy levels of the system, induced by the giant s-d spin-splitting of the electronic states.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1000-1004
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductance Anomalies in Strained Quantum Wires: the Case of PbSe and PbTe
Autorzy:
Grabecki, G.
Wróbel, J.
Dietl, T.
Sawicki, M.
Skośkiewicz, T.
Papis, E.
Kamińska, E.
Piotrowska, A.
Frank, N.
Ueta, Y.
Sprinholtz, G.
Bauer, G.
Powiązania:
https://bibliotekanauki.pl/articles/1950800.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
Opis:
We show that conducting edge channels are formed in free standing wires of PbSe/BaF$\text{}_{2}$ and PbTe/BaF$\text{}_{2}$ as temperature is lowered. The effect results from spatially inhomogeneous strain caused by a difference between the thermal expansion coefficients of the epilayer and the substrate. The presence of the edge channels can explain anomalous mesoscopic effects observed previously in these wires.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 797-800
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-Probe Measurements of Electron Transport in GaN:Si/(Ga,Mn)N/GaN:Si Spin Filter Structures
Autorzy:
Kalbarczyk, K.
Foltyn, M.
Grzybowski, M.
Stefanowicz, W.
Adhikari, R.
Li, Tian
Kruszka, R.
Kamińska, E.
Piotrowska, A.
Bonanni, A.
Dietl, T.
Sawicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/1398574.pdf
Data publikacji:
2016-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Dc
73.40.Cg
73.43.Qt
78.55.Cr
Opis:
Results of two-probe magnetoresistance studies in GaN:Si/(Ga,Mn)N/GaN:Si prospective spin filter structures are reported. It is postulated that transport characteristics are strongly influenced by highly conductive threading dislocations and that shrinking of the device size partially mitigates the issue. Simultaneously, maxima at ≈1500 Oe on overall weak, up to 2%, negative magnetoresistance are seen at low temperature, whose origin has been tentatively assigned to effects taking place at the contacts areas.
Źródło:
Acta Physica Polonica A; 2016, 130, 5; 1196-1198
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic, Structural, and Optical Properties of Low Temperature ZnMnO Grown by Atomic Layer Epitaxy
Autorzy:
Wójcik, A.
Kiecana, M.
Kopalko, K.
Godlewski, M.
Guziewicz, E.
Yatsunenko, S.
Łusakowska, E.
Minikayev, R.
Paszkowicz, W.
Świątek, K.
Wilamowski, Z.
Sawicki, M.
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2044552.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.Jk
68.55.Ln
68.55.Nq
78.66.Hf
81.15.Kk
Opis:
Magnetic, structural, and optical properties of ZnMnO films grown with atomic layer epitaxy are discussed. Atomic layer epitaxy films were grown at low temperature using organic zinc and manganese precursors. From magnetometry and electron spin resonance investigations we conclude that lowering of a growth temperature significantly limits formation of Mn precipitates and inclusions of different foreign phases of manganese oxides to ZnMnO host.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 915-921
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dimensional Crossovers in Magnetoresistance of Submicron Films and Wires of CdTe:In
Autorzy:
Jaroszyński, J.
Wróbel, J.
Sawicki, M.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Dietl, T.
Kamińska, E.
Papis, E.
Piotrowska, A.
Duś, R.
Nowakowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1952536.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
Opis:
We present millikelvin studies of magnetoresistance for epitaxial films and wires of CdTe:In. In comparison to the data with theoretical predictions for the weakly localized regime we put into the evidence the presence of the temperature-induced dimensional crossovers in the studied systems. Our measurements probe the electron phase-breaking rate and indicate that the main dephasing mechanism arises from electron scattering from thermal fluctuations of three- or two-dimensional electron liquid.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 1027-1031
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical and Structural Properties of Ohmic Contacts to n-Type and High Resistivity CdTe
Autorzy:
Kamińska, E.
Piotrowska, A.
Guziewicz, M.
Gierlotka, S.
Papis, E.
Łusakowski, J.
Szadkowski, K.
Kwiatkowski, S.
Dietl, T.
Grabecki, G.
Jaroszyński, J.
Karczewski, G.
Zakrzewski, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/1873052.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Ns
Opis:
The interaction between CdTe and In during the formation of an ohmic contact has been investigated. Emphasis is placed on the study of the effect of thermally induced sublimation of cadmium on electrical properties of contacts. Presented results prove the effectiveness of cap annealing and rapid thermal processing in fabrication of improved ohmic contacts with limited Cd losses during the contacting procedure.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 411-414
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetooptical Properties of (Ga,Fe)N Layers
Autorzy:
Papierska, J.
Rousset, J.
Pacuski, W.
Kossacki, P.
Golnik, A.
Nawrocki, M.
Gaj, J.
Suffczyński, J.
Kowalik, I.
Stefanowicz, W.
Sawicki, M.
Dietl, T.
Navarro-Quezada, A.
Faina, B.
Li, T.
Bonanni, A.
Powiązania:
https://bibliotekanauki.pl/articles/1492954.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Hx
78.20.Ls
71.35.Ji
Opis:
Magnetooptical properties of (Ga,Fe)N layers containing various concentrations of Fe-rich nanocrystals embedded in paramagnetic (Ga,Fe)N layers are reported. Previous studies of such samples demonstrated that magnetization consists of a paramagnetic contribution due to substitutional diluted Fe ions as well as of ferromagnetic and antiferromagnetic components originating from Fe-rich nanocrystals, whose relative abundance can be controlled by the growth conditions. The nanocrystals are found to broaden and to reduce the magnitude of the excitonic features. However, the ferromagnetic contribution, clearly seen in SQUID magnetometry, is not revealed by magnetic circular dichroism. Possible reasons for differences in magnetic response determined by magnetic circular dichroism and SQUID measurements are discussed.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 921-923
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wysiłku fizycznego na zapasy akseroftolu w wątrobie i nerkach szczura
The effect of exercise on the reserves of axerophtol in the liver and kidneys of rats
Autorzy:
Dietl, B.
Opuszynska, T.
Powiązania:
https://bibliotekanauki.pl/articles/874680.pdf
Data publikacji:
1961
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Źródło:
Roczniki Państwowego Zakładu Higieny; 1961, 12, 5
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-36 z 36

    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