Autor: Strecka, J - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Magnetization Process and Adiabatic Demagnetization of the Antiferromagnetic Spin-1/2 Heisenberg Cubic Cluster
Autorzy:: Strečka, J.
Čisárová, J.
Powiązania:: https://bibliotekanauki.pl/articles/1366469.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.10.Jm
75.30.Sg
75.40.Cx
75.50.Ee
75.60.Ej
Opis:: A full energy spectrum of the spin-1/2 Heisenberg cubic cluster is used to investigate a low-temperature magnetization process and adiabatic demagnetization of this zero-dimensional 2×2×2 quantum spin system. It is shown that the antiferromagnetic spin-1/2 Heisenberg cube exhibits at low enough temperatures a stepwise magnetization curve with four intermediate plateaux at zero, one quarter, one half, and three quarters of the saturation magnetization. We have also found the enhanced magnetocaloric effect close to level-crossing fields that determine transitions between the intermediate plateaux.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 26-27
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Anomalous Magnetocaloric Properties of the Spin-1/2 Ising Model on a Decorated Square Lattice in a Vicinity of Second-Order Phase Transition
Autorzy:: Karľová, K.
Strečka, J.
Powiązania:: https://bibliotekanauki.pl/articles/1032487.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.10.Hk
75.30.Sg
75.40.-s
75.50.Cc
Opis:: Magnetocaloric properties of the spin-1/2 Ising model on a decorated square lattice in a transverse magnetic field are investigated by the use of a generalized decoration-iteration transformation, which establishes a rigorous mapping correspondence with the zero-field spin-1/2 Ising model on a square lattice. The temperature dependence of the entropy, the isothermal entropy change and the adiabatic temperature change display anomalous singular behavior in a vicinity of a second-order phase transition. The large inverse magnetocaloric effect can be found in the isothermal entropy change within the temperature interval, which is delimited by the critical temperatures at zero and non-zero transverse fields.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 170-172
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Inverse magnetocaloric effect in spin-1/2 Fishers super-exchange antiferromagnet
Autorzy:: Gálisová, L.
Strečka, J.
Powiązania:: https://bibliotekanauki.pl/articles/1052954.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.50.+q
75.30.Et
75.30.Sg
75.30.Kz
Opis:: The isothermal entropy change and the adiabatic temperature change are rigorously calculated for the exactly solved spin-1/2 Fisher's super-exchange antiferromagnet in order to examine magnetocaloric properties of the model in a vicinity of the second-order phase transition. It is shown that the large inverse magnetocaloric effect occurs around the temperature interval T_c(h≠0) < T < T_c(h=0) for any magnetic-field change Δh:0 → h. The most pronounced inverse magnetocaloric effect can be found for the magnetic-field change, which coincides with the critical field of a zero-temperature phase transition from the antiferromagnetically ordered ground state to the paramagnetic one.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 627-629
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Ground State, Magnetization Process, and Magnetocaloric Effect of the Exactly Tractable Spin-Electron Tetrahedral Chain
Autorzy:: Gálisová, L.
Strečka, J.
Powiązania:: https://bibliotekanauki.pl/articles/1384829.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.10.Pq
75.60.Ej
75.30.Sg
05.50.+q
Opis:: A hybrid spin-electron system on one-dimensional tetrahedral chain, in which the localized Ising spin regularly alternates with the mobile electron delocalized over three lattice sites, is exactly investigated using the generalized decoration-iteration transformation. The system exhibits either the ferromagnetic or antiferromagnetic ground state depending on whether the ferromagnetic or antiferromagnetic interaction between the Ising spins and mobile electrons is considered. The enhanced magnetocaloric effect during the adiabatic demagnetization suggests a potential use of the investigated system for low-temperature magnetic refrigeration.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 216-218
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Isothermal Entropy Change and Adiabatic Change of Temperature of the Antiferromagnetic Spin-1/2 Ising Octahedron and Dodecahedron
Autorzy:: Karľová, K.
Strečka, J.
Madaras, T.
Powiązania:: https://bibliotekanauki.pl/articles/1032208.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Sg
75.10.Hk
75.50.Ee
75.50.Xx
Opis:: The spin-1/2 Ising octahedron and dodecahedron with a unique antiferromagnetic interaction display an outstanding magnetization jump at zero magnetic field, which consequently leads to a giant magnetocaloric effect during the adiabatic demagnetization. In the present work we report temperature dependences of two basic magnetocaloric response functions: the isothermal entropy change and the adiabatic change of temperature. It is shown that the Ising octahedron and dodecahedron generally exhibit a large negative isothermal entropy change upon increase of the magnetic field, which serves in evidence of their cooling performance.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 630-632
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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