Autor: Onyszkiewicz, Z. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Ising Model of Thin Film with Random Surface Field
Autorzy:: Onyszkiewicz, Z.
Tematy:: 75.70.-i; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1891842.pdf Link otwiera się w nowym oknie
Opis:: Thermodynamical properties of an Ising model of a ferromagnetic thin film deposited onto a ferromagnetic substrate of rough surface contacting the thin film were studied. The influence of the interaction between the substrate and the film as well as the effect of the substrate surface roughness were found to be describable in this model by a temperature dependent random surface field. Magnetization of the thin film was calculated for various temperatures at different assumed values of the substrate Curie temperature as well as for various surface roughness grades of the substrate and various couplings between the film and the substrate.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Nonequilibrium Reduced-Density Operator for Nanoscopic Systems
Autorzy:: Jacyna-Onyszkiewicz, Z.
Tematy:: 05.30.-d
05.70.Ln; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2035619.pdf Link otwiera się w nowym oknie
Opis:: Retarded forms of the nonequilibrium reduced-density operator are derived from the generalized Schrödinger variational principle of a system with both mechanical and thermal perturbations, taking into account the additional condition that the values of generalized thermodynamic coordinates are fixed at infinitely remote past. This reduced density operator may be useful in describing nonequilibrium properties of nanoscopic and mesoscopic systems, as well as ultrathin films. With the help of this reduced-density operator the generalized Green-Kubo formulae are obtained.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Generalised Equilibrium Reduced-Density Operator
Autorzy:: Jacyna-Onyszkiewicz, Z.
Tematy:: 03.65.Ca
05.30.-d; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1030814.pdf Link otwiera się w nowym oknie
Opis:: Equilibrium reduced-density operators for subsystems of the universe are derived from the generalised Schrödinger variational principle, additionally assuming that the values of von Neumann entropy for the subsystems are fixed and higher than zero. The obtained reduced-density operator may be useful for description of the properties of an arbitrary system (macroscopic, mesoscopic, nanoscopic, or microscopic) in the equilibrium mixed state.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: The Influence of Non-Magnetic Substrate on Spatial Distribution of Gaussian Fluctuations of Molecular Field in Magnetic Nanoparticles and Ultrathin Films
Autorzy:: Łosiński, R.
Onyszkiewicz, Z.
Tematy:: 75.10.Hk
75.70.-i; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2013980.pdf Link otwiera się w nowym oknie
Opis:: An Ising (s=1) model of ferromagnetic nanoparticles and ultrathin films of the sc structure deposited on a non-magnetic substrate is considered. The substrate was assumed to affect the crystal field around the atoms lying closest to it. Consequently, the one-ion anisotropy constant of spin moments of these atoms becomes dependent on the appropriate component of the tensor of the magnetic structure deformation. This dependence was assumed to be linear. To obtain approximations of the Gaussian fluctuations of molecular field, the generalised equilibrium reduced density operator, along with the Feynman diagram technique were used. As a result, temperature dependences of the spatial distributions of mean fluctuations of the magnetic field versus the changes in the one-ion anisotropy constant induced by the non-magnetic substrate were obtained.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Theoretical Investigation of the Complete Phase Diagram of the SmMn$\text{}_{2}$Ge$\text{}_{2}$ Metamagnet
Autorzy:: Polaszek, P.
Onyszkiewicz, Z.
Tematy:: 75.30.Kz; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1929828.pdf Link otwiera się w nowym oknie
Opis:: A two-sublattice Ising model with spatial four-spin and six-spin anisotropy added in order to describe SmMn$\text{}_{2}$Ge$\text{}_{2}$ metamagnet is discussed. The complete phase diagrams for this metamagnet as a function of hydrostatic pressure are obtained.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Gaussian Fluctuations of Molecular Field in Quasi-One-Dimensional Ising Model
Autorzy:: Onyszkiewicz, Z.
Wierzbicki, A.
Tematy:: 75.10.Hk
75.70.Ak; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2007877.pdf Link otwiera się w nowym oknie
Opis:: Quasi-one-dimensional spin systems described by an Ising-like Hamiltonian with a strong space anisotropy (s=1/2) are investigated. Magnetic properties of this model are examined in the approximation including Gaussian fluctuations of molecular field. This paper reports an attempt at obtaining more accurate results for Gaussian fluctuation of molecular field by an exact formula for mean fluctuations of a spin.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Collective Excitations in Heisenberg Ultrathin Films with Inhomogeneous Spatial Distribution of Magnetisation
Autorzy:: Łosiński, R.
Onyszkiewicz, Z.
Tematy:: 75.70.-i
75.10.Jm; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2014320.pdf Link otwiera się w nowym oknie
Opis:: The influence of non-magnetic substrate on the collective excitation of the Heisenberg (s=1/2) ferromagnetic ultrathin films with homogeneous and inhomogeneous spatial distribution of magnetization is investigated. It has been proved that the collective excitation spectrum of ultrathin film may, to a significant degree, depend on the value of the coefficient characterizing the film coupling with its substrate.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Spatial Dependence of Magnetization and Gaussian Fluctuations of Molecular Field in an Ising Nanopyramid Interacting with the Substrate
Autorzy:: Borkowski, L.
Jacyna-Onyszkiewicz, Z.
Tematy:: 75.75.+a; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1810597.pdf Link otwiera się w nowym oknie
Opis:: We study thermodynamic properties of an Ising model of a ferromagnetic nanoscopic pyramid deposited on a ferromagnetic bulk substrate. The influence of the interaction between the pyramid and the substrate is calculated in terms of the reduced-state (density) operator used for description of thermodynamic properties of nanoscopic systems. The spatial distribution of magnetization in the nanopyramid is obtained in the Gaussian fluctuations approximation.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Gaussian Fluctuations of Two Molecular Fields in the Blume-Emery-Griffiths Model
Autorzy:: Jaworski, W.
Jacyna-Onyszkiewicz, Z.
Tematy:: 75.10.Dg
75.10.Hk
75.10.Jm; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1505093.pdf Link otwiera się w nowym oknie
Opis:: The Blume-Emery-Griffiths model for spins S=1 in a bilayer with z=5 nearest neighbours is studied with the use of Gaussian fluctuations approximation. The fluctuations of two molecular fields, connected with two order parameters, are introduced. Their influence on phase diagrams for non-negative values of the biquadratic coupling constant is taken under consideration. The results are compared with those obtained by the mean-field approximation and discussed.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Spatial Distribution of Magnetization in the Pyramid-Like Ising Nanoscopic System Interacting with the Substrate
Autorzy:: Borkowski, L.
Jacyna-Onyszkiewicz, Z.
Tematy:: 75.75.+a; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1814026.pdf Link otwiera się w nowym oknie
Opis:: We study thermodynamic properties of an Ising model of a ferromagnetic nanoscopic pyramid deposited onto a ferromagnetic bulk substrate. The influence of the interaction between the pyramid and the substrateis calculated in terms of the reduced-state (density) operator used for description of thermodynamic properties of nanoscopic systems. The spatial distribution of the magnetization in the nanoscopic pyramid is obtained in the molecular field approximation.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "Onyszkiewicz, Z." wg kryterium: Autor