Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Implications of Invalid Conversions between Crystal-Field Parameters and Zero-Field Splitting Ones Used in Superposition Model

100%
Rudowicz C., Karbowiak M.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 5
1215-1219
EN
The methodology used in recent study of the zero-field splitting parameters of Cr^{3+} ions at various orthorhombic symmetry sites in LiKSO_4 by Pandey and Kripal is critically commented on. We argue that the crystal field parameters, B_{kq}, in the Wybourne notation, which were calculated using the superposition model for Cr^{3+} ions in LiKSO_4, may only be converted into the crystal field parameters in the Stevens notation. Regrettably, the authors have also converted the latter parameters supposedly into the zero-field splitting parameters D and E in the conventional notation. Such direct conversions are fundamentally incorrect and constitute factual invalid usage of the conversion relations between the crystal field (ligand field) parameters and the zero-field splitting ones. The cases of an implied usage of the invalid conversion relations between the crystal field parameters and the zero-field splitting parameters occurring in recent literature are also outlined. Pandey and Kripal have found the zero-field splitting parameters theoretically evaluated in this way to be in good agreement with the experimental values. However, the faulty methodology renders the conclusion that Cr^{3+} ions enter into the LiKSO_4 lattice at the substitutional K^{+} sites unjustified. Several other conceptual problems arising from misinterpretations of the crucial notions identified therein are also discussed and clarified.
2
Content available remote

Comparative Analysis of Experimental and Theoretical Zero-Field Splitting and Zeeman Electronic Parameters for Fe²⁺ Ions in FeX₂·4H₂O (X = F, Cl, Br, I) and [Fe(H₂O)₆](NH₄)₂(SO₄)₂

100%
Zając M., Rudowicz C.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 1
19-23
EN
Spectroscopic and magnetic properties of Fe²⁺ (3d⁶; S=2) ions at orthorhombic sites in FeX₂·4H₂O (X = F, Cl, Br, I) crystals are compared with those in [Fe(H₂O)₆](NH₄)₂(SO₄)₂ (FASH). The microscopic spin Hamiltonian modeling utilizing the package MSH/VBA enables prediction of the zero-field splitting parameters and the Zeeman electronic ones. Wide ranges of values of the microscopic parameters, i.e. the spin-orbit (λ), spin-spin (ρ) coupling constants, and the crystal-field (ligand-field) energy levels (Δp_{i}) within the ⁵D multiplet are considered to establish the dependence of the zero-field splitting parameters b_{k}^{q} (in the Stevens notation) and the Zeeman factors g_{i} on λ, ρ, and Δp_{i}. By matching the theoretical spin Hamiltonian parameters and the experimental ones measured by EMR, the suitable values of λ, ρ, and Δp_{i} are determined. The novel aspect is prediction of the fourth-rank zero-field splitting parameters and the ρ (spin-spin)-related contributions, not considered in previous studies. The MSH predictions provide guidance for high-magnetic field and high-frequency EMR measurements.
3
Content available remote

EMR Data on Mn(III; S=2) Ions in MnTPPCl Complex Modelled by Microscopic Spin Hamiltonian Approach

100%
Tadyszak K., Rudowicz C.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 1
15-19
EN
The electron magnetic resonance data on high-spin (S =2) manganese(III) 3d⁴ ion in tetraphenylporphyrinato chloride complex (MnTPPCl) obtained by high-frequency techniques are reanalysed. Preliminary results of semiempirical modeling of the spin Hamiltonian parameters for Mn(III) in MnTPPCl are presented. The microscopic spin Hamiltonian approach is utilized to predict the zero-field splitting and the Zeeman electronic parameters. It is found that for Mn(III) ions in MnTPPCl matching the experimental spin Hamiltonian parameters and the theoretical ones based on the ligand-field energy levels (Δ_{i}) within the ⁵D multiplet only may not be suitable for this system. Contributions due to the levels arising from the higher-lying ³H multiplet need to be taken into account in order to determine the reasonable values of microscopic parameters describing Mn(III) ions in MnTPPCl.
4
Content available remote

Conversions of the Second-Rank Zero Field Splitting Parameters Measured Assuming the Fictitious Spin S'=1 to those for the Effective Spin S̃=2

100%
Kozanecki M., Rudowicz C.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 1
11-14
EN
We investigate feasibility of comparison between the zero field splitting parameters obtained experimentally based on the spin Hamiltonian with the fictitious spin S'=1 and those with the effective spin S̃=2. The former zero field splitting parameters have recently been measured for Fe²⁺ ions in forsterite Mg₂SiO₄, whereas the latter zero field splitting parameters are available in literature, e.g. for Fe²⁺ and Cr²⁺ (S̃=2) ions. It turns out that no unique direct comparison is feasible and hence appropriate conversion relations need to be derived. Methodology for such conversions is outlined. Various combinations of the possible energy level schemes for the spin S̃=2 and S'=1 are briefly described. Illustrative preliminary results concerning appropriate conversions of the second-rank zero field splitting parameters measured by high-frequency EMR for Fe²⁺ in natural and synthetic forsterite are presented. Detailed results and full analysis will be given elsewhere.
5
Content available remote

Spin Hamiltonian Parameters for Co²⁺ Ions in PbMoO₄ Crystal - Interplay between the Fictitious Spin S'=1/2 and the Effective Spin S̃ =3/2

81%
Piwowarska D., Kaczmarek S., Gnutek P., Rudowicz C.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 1
73-76
EN
The interplay between the fictitious spin S' = 1/2 and the effective spin S̃=3/2 for Co²⁺(3d⁷) ions is considered. The available experimental data on the Ze g_{i}' factors for the two Co²⁺ complexes in PbMoO₄ obtained using the fictitious "spin" S'=1/2 description serve for determination of the Zeeman g_{i} factors corresponding to the effective spin S̃ =3/2. The second-rank zero-field splitting parameters D and E (S̃ = 3/2) are also indirectly determined from the experimental EMR data by employing the formulas arising from projection of the g_{i}(S̃=3/2) factors onto the g_{i}'(S' = 1/2) factors. The so-determined second-rank zero-field splitting parameters and g_{i}(S̃ = 3/2) factors will enable comparison with the respective quantities obtained in a subsequent paper using a combined modeling approach.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.