Autor: Ropka, Z. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Three localized f electrons in UPd₂Al₃ and in UGe₂ intermetallics
Autorzy:: Radwanski, R.
Nalecz, D.
Ropka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1062036.pdf
Data publikacji:: 2016-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.70.Ej
75.10.Dg
75.30.Gw
Opis:: We have calculated the strength of the excitations between the crystal-field states which are in agreement with inelastic-neutron-scattering results. This agreement confirms the existence in the heavy-fermion superconductor UPd₂Al₃ the crystal-field electronic structure being the finger-print of the U^{3+} ions with three localized f electrons forming strongly-correlated atomic-like quantum system 5f³. The ionic integrity and the low-energy crystal-field electronic structure is preserved in this metallic system in the meV scale as has been postulated in the Quantum Atomistic Solid State theory (QUASST). We provide preliminary results with the U^{3+} ion in UGe₂ showing the ground-state eigenfunction which reproduces the ordered magnetic-moment value of 1.48 μ_{B}. This moment is composed from the dominant orbital contribution (2.6 μ_{B}) and the opposite spin moment (1.12 μ_{B}).
Źródło:: Acta Physica Polonica A; 2016, 130, 2; 545-550
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Crystal-Field Interactions in $RPd_2Al_3$ Intermetallics (R = Pr, Nd, Sm, and U)
Autorzy:: Radwanski, R.
Nalecz, D.
Ropka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1374347.pdf
Data publikacji:: 2014-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.70.Ej
75.10.Dg
Opis:: Magnetic and electronic properties of $NdPd_2Al_3$ have been nicely described with the $Nd^{3+}$ ions within the crystal-field theory revealing that all Nd atoms equally contribute to the temperature dependence of the paramagnetic susceptibility and of the heat capacity with the λ-peak. We consistently described paramagnetic and magnetically-ordered state. The fine electronic structure of the $Nd^{3+}$ ion nicely correlates with the electronic structure of the $U^{3+}$ ion in $UPd_2Al_3$ giving strong evidence for the trivalent uranium state in the isostructural heavy-fermion superconductor $UPd_2Al_3$.
Źródło:: Acta Physica Polonica A; 2014, 126, 4a; A-32-A-35
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Localized f electron aspect in heavy-germion intermetallic YbRh₂Si₂
Autorzy:: Radwanski, R.
Nalecz, D.
Fedyk, S.
Ropka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1048149.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: Heavy fermion
crystal field
Kondo resonance
YbRh₂Si₂
Opis:: We point out that there is more and more experiments showing the almost perfect localization of thirteen f-electrons in the canonical heavy-fermion system: YbRh₂Si₂. The revealing of the Yb³⁺ crystal-field (CEF) states confirms the Quantum Atomistic Solid State Theory. QUASST was the only theory, which has claimed from 1992 the existence of the discrete CEF electronic structure and the Kramers doublet ground state in heavy-fermion intermetallics. The removal of the on-site Kramers degeneracy via spin-dependent interactions is origin of the large specific heat at low temperatures (a hallmark of the heavy-fermion phenomena) and of low-energy neutral spin-like excitations. The Kondo resonance is related to the slight splitting of the Kramers doublet ground state of the Yb³⁺ ion.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 387-390
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Really First Principles Calculations for CoF₃
Autorzy:: Radwanski, R.
Nalecz, D.
Krupska, M.
Piwowarczyk, T.
Ropka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1385724.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.30.Fc
75.10.Dg
Opis:: We have derived the low-energy electronic structure of CoF₃, originating from the strongly-correlated 3d⁶ system of the Co³⁺ ion, taking into account the crystal-field interactions, with a relatively weak trigonal distortion, and the relativistic spin-orbit interaction. We have calculated from really first-principles the relevant crystal-field interactions. With the discrete electronic structure for 3d electrons we have described the magnetic properties (the value of the magnetic moment and its direction). The moment direction is determined by the local off-octahedral trigonal distortion proving the single-ion origin of the magnetocrystalline anisotropy. We evaluated the orbital moment and the strength of spin interactions responsible for the formation of the magnetic state. Our studies indicate that calculations of the electronic structure of a 3d compound for the physically-adequate description of the magnetic properties has to be performed at the meV scale.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 391-393
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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