Temat: 61.72.Lk - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Anomalous Behavior of the Hall Effect in III-V Heterostructures
Autorzy:: Dziuba, Z.
Górska, M.
Marczewski, J.
Przesławski, T.
Regiński, K.
Tematy:: 61.72.Lk
72.80.Ey; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2012953.pdf Link otwiera się w nowym oknie
Opis:: The Hall effect and magnetoresistance were measured in the InAs/GaAs heterostructure at temperatures from 300 K down to 3 K, in a magnetic field range from 0.01 to 1.5 T. The anomalous magnetic field dependence of the Hall coefficient in the InAs/GaAs heterostructure in magnetic fields below 0.1 T was explained as due to an extraordinary Hall effect caused by skew scattering on dislocations.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Si_{1-x}Ge_{x} Single Crystals Grown by the Czochralski Method: Defects and Electrical Properties
Autorzy:: Argunova, T.
Je, J.
Kostina, L.
Rozhkov, A.
Grekhov, I.
Tematy:: 61.72.Ff
61.72.Lk
72.15.Eb; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1399444.pdf Link otwiera się w nowym oknie
Opis:: Defects in $Si_{1-x}Ge_{x}$ single crystals (2-8.5 at.% Ge) grown by the Czochralski method are investigated by synchrotron white beam topography and phase contrast imaging techniques. As the Ge concentration increases, dislocation structure evolves from individual dislocations to slip bands and sub-grain boundaries. We discuss the effect of dislocations on the electrical characteristics such as resistivity $\rho_{v}$, the Hall hole mobility $\mu_{p}$ and carrier lifetime τ_{e}. Diodes are fabricated by bonding $p-Si_{1-x}Ge_{x}$ to n-Si wafers to investigate I-V characteristics and reverse recovery process. I-V characteristics are not deteriorated in spite of a five times decrease in $\tau_{e}$ with Ge concentration. A small reverse recovery time (determined by the accumulated charge) can be achieved for an optimised preset Ge concentration.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: 3D Discrete Dislocation Dynamics: Influence of Segment Mobility on Critical Shear Stress
Autorzy:: Záležák, T.
Dlouhý, A.
Tematy:: 61.72.Hh
61.72.Lk
62.20.Hg; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402114.pdf Link otwiera się w nowym oknie
Opis:: We use 3D discrete dislocation dynamics technique to study a low-angle tilt boundary migration subjected to applied shear stress at high temperatures, where diffusion significantly contributes to the dislocation motion. The model considers Peach-Koehler forces due to interactions between individual straight dislocation segments. The model also addresses dislocation plasticity in a field of impenetrable incoherent spherical precipitates. Velocities of the individual dislocation segments are calculated in relation to the crystallography of the material. Several calculation series have been carried out for different velocity and driving force relations. The results show that there exists a critical applied shear stress, below which the low angle dislocation boundary cannot surpass the rigid precipitates and remains in an equilibrium configuration. This agrees with experimental results obtained in creep tests of dispersion strengthened alloys. The critical stresses have been calculated also for situations where the applied stress was decreased during the interaction between the low-angle tilt boundary and the precipitates.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Phason Contribution to the Dislocation Loop Bias in Quasicrystals
Autorzy:: Lavrova, G.
Turkin, A.
Bakai, A.
Tematy:: 61.44.Br
61.72.Lk
61.80.Az; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1203098.pdf Link otwiera się w nowym oknie
Opis:: We develop a model of the absorption of vacancies and self-interstitial atoms by dislocation loops and associated phason defects in quasicrystals under irradiation. The capture efficiency and the bias of the loop for radiation point defects are evaluated for variable loop sizes. Numerical calculation of these quantities is performed for comparison. It is shown that phason defects decrease the total bias of the dislocation loop in a quasicrystal.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Numerical Simulations of Glide Dislocations in Persistent Slip Band
Autorzy:: Kolář, M.
Beneš, M.
Kratochvíl, J.
Pauš, P.
Tematy:: 02.70.Bf
61.72.Lk
02.30.Jr; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402064.pdf Link otwiera się w nowym oknie
Opis:: For the purpose of estimation of possible inaccuracy in standard discrete dislocation dynamics simulations, we study the motion of interacting dislocations in two regimes: the standard stress control and the total strain control. For demonstration of the difference, we consider two dislocations of opposite signs, gliding in parallel slip planes in a channel of a persistent slip band. Exposed to the applied stress, the dislocations move, bow out, and form a dipole. We investigate the passing stress needed for the dislocations to escape each from other, considering the stress controlled regime and the total strain controlled regime. The motion is described by the mean curvature flow and treated by means of the direct (parametric) method. The results of numerical experiments indicate that the stress control and the total strain control provide upper and lower estimate of the passing stress, respectively, and that these two estimates differ by approximately 10%.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Numerical Simulation of Dislocation Cross-Slip with Annihilation in Non-Symmetric Configuration
Autorzy:: Pauš, P.
Beneš, M.
Kratochvíl, J.
Tematy:: 02.70.Bf
61.72.Lk
02.30.Jr; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1402142.pdf Link otwiera się w nowym oknie
Opis:: The interpretation of the experimentally determined critical distance of the screw dislocation annihilation in persistent slip bands is still an open question. We attempt to analyze this problem using the discrete dislocation dynamics simulations. Dislocations are represented by parametrically described curves. The model is based on the numerical solution of the dislocation motion law belonging to the class of curvature driven curve dynamics. We focus on the simulation of the cross-slip of one edge dislocation curve bowing out of the wall of a persistent slip band channel and one screw dislocation gliding through the channel. The dislocations move under their mutual interaction, the line tension and the applied stress. A cross-slip leads to annihilation of the dipolar parts. In the changed topology each dislocation evolves in two slip planes and the plane where cross-slip occurred. The goal of our work is to develop and test suitable mathematical and physical model of the situation. The results are subject to comparison with symmetric configuration of two screw dislocations studied in papers by Pauš et al. The simulation of the dislocation evolution and merging is performed by the improved parametric approach. Numerical stability is enhanced by the tangential redistribution of the discretization points.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Simulation of Dislocation Annihilation by Cross-Slip
Autorzy:: Pauš, P.
Beneš, M.
Kratochvíl, J.
Tematy:: 02.70.Bf
61.72.Lk
02.30.Jr; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1418510.pdf Link otwiera się w nowym oknie
Opis:: This contribution deals with the numerical simulation of dislocation dynamics, their interaction, merging and changes in the dislocation topology. The glide dislocations are represented by parametrically described curves moving in slip planes. The simulation model is based on the numerical solution of the dislocation motion law belonging to the class of curvature driven curve dynamics. We focus on the simulation of the cross-slip of two dislocation curves where each curve evolves in a different slip plane. The dislocations evolve, under their mutual interaction and under some external force, towards each other and at a certain time their evolution continues outside slip planes. During this evolution the dislocations merge by the cross-slip occurs. As a result, there will be two dislocations evolving in three planes, two planes, and one plane where cross-slip occurred. The goal of our work is to simulate the motion of the dislocations and to determine the conditions under which the cross-slip occurs. The simulation of the dislocation evolution and merging is performed by improved parametric approach and numerical stability is enhanced by the tangential redistribution of the discretization points.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Deep-Level Defects at Lattice-Mismatched GaAsSb/GaAs Interface
Autorzy:: Wosiński, T.
Mąkosa, A.
Raczyńska, J.
Tematy:: 73.20.Hb
61.72.Lk
71.55.Eq; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1872887.pdf Link otwiera się w nowym oknie
Opis:: Lattice-mismatch-induced defects were studied by means of deep-level transient spectroscopy in high-purity GaAs$\text{}_{1-x}$Sb$\text{}_{x}$ layers (x = O to 3%) grown by liquid phase epitaxy on GaAs substrates. Microscopic nature and formation mechanism of two electron traps and two hole traps, which appeared in the layers as a result of Sb incorporation into the crystal lattice, are briefly discussed.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Conventional and Synchrotron X-Ray Topography of Defects in the Core Region of $SrLaGaO_4$
Autorzy:: Malinowska, A.
Lefeld-Sosnowska, M.
Wieteska, K.
Wierzchowski, W.
Pajączkowska, A.
Graeff, W.
Tematy:: 61.72.Ff
61.72.Nn
61.72.Lk
61.72.Qq; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1812255.pdf Link otwiera się w nowym oknie
Opis:: $SrLaGaO_4$ single crystals are perspective substrate materials for high temperature superconductors thin films, elements of thermal radiation receivers and other electronic devices. The defect structure of the Czochralski grown $SrLaGaO_4$ crystal was investigated by means of X-ray topography exploring both conventional and synchrotron sources. The crystal lattice defects in the core region of the crystal were investigated. The regular network of defects arranged in rows only in ⟨100⟩ direction was observed. Owing to high resolution of synchrotron radiation white beam back reflection topographs one can distinguish individual spots forming the lines of the rows. It can be supposed that these elongated rod-like volume defects are located in 100 lattice planes forming a kind of walls. They are built approximately of the same phase as crystal but crystallize at a different moment than a rest of the crystal due to the constitutional supercooling.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Electric-Elastic Field Induced by a Straight Dislocation in One-Dimensional Quasicrystals
Autorzy:: Yang, L.
Gao, Y.
Pan, E.
Waksmanski, N.
Tematy:: 61.44.Br
61.72.Lk
62.20.D-; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1202982.pdf Link otwiera się w nowym oknie
Opis:: By using the generalized Stroh formalism, the electric-elastic field induced by a straight dislocation parallel to a periodic axis of a one-dimensional quasicrystal is obtained. The derivation is concise and the solution is in an exact closed form. As an illustration, the electric-elastic fields around a straight dislocation in a one-dimensional hexagonal quasicrystal are studied. Besides the interesting numerical results presented, the generalized Stroh formalism can be applied to more complicated dislocation problems in quasicrystals.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "61.72.Lk" wg kryterium: Temat