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: 7

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
Publication available in full text mode
Content available

Competing Magnetic Interactions in Zn_3Fe_4V_6O_{24} Studied by Electron Paramagnetic Resonance

100%
Zolnierkiewicz G., Guskos N., Typek J., Blonska-Tabero A.
Acta Physica Polonica A
|
2006
|
vol. 109
|
issue 4-5
675-679
EN
A multicomponent vanadate M_3Fe_4V_6O_{24} sample with non-magnetic M = Zn(II) ions was synthesized by the solid state reaction method using stoichiometric mixtures of the 80mol% FeVO_4 and 20mol% Zn_3(VO_4)_2. The temperature dependence of the EPR spectra was performed in the 90-280 K temperature range. The resonance field and the integrated intensity of the EPR line showed minimum value of both parameters at≈200 K. It is suggested that a part of the sample is displaying tendency to form an antiferromagnetic ordered state (or the magnetic clusters) above this temperature while below the ferromagnetic interaction of the main part of material is dominating. This behaviour is attributed to the inherent magnetic inhomogeneity of the system due to the presence of the ferromagnetic or antiferromagnetic spin clusters.
2
Content available remote

Parametrization of the Vibronic Contributions to the b^{0}_{4} Spin-Hamiltonian Parameters for ^{8}S_{7/2} Ground State Ions in Fluoroperovskites

100%
Rewaj T., Kuriata J., Typek J., Buzare J.
Acta Physica Polonica A
|
1993
|
vol. 84
|
issue 6
1143-1149
EN
Parametrization of phonon induced contributions to the experimentally determined temperature dependence of the b_{0}^{4} spin-Hamiltonian parameter for Gd_{3+} doped RbCaF_{3}, CsCaF_{3}, RbCdF_{3} and TlCdF_{3} single crystals is discussed. Three physically different parametrization schemes are considered, i.e. that of Einstein, Debye and Huang. It is found that the model of Huang, which predicts that the phonon induced contributions should be proportional to the Debye-Waller factor, describes best the experimental data. The method allowing determination of the Debye temperature from EPR data is also suggested.
3
Content available remote

Magnetic Study of Phases in FeVO₄-Co₃V₂O₈ System

76%
Guskos N., Zolnierkiewicz G., Pilarska M., Typek J., Blonska-Tabero A., Aidinis C.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 1
24-30
EN
Magnetic properties of four nFeVO₄/(1-n)Co₃V₂O₈ samples obtained in reactions between FeVO₄ and Co₃V₂O₈ (n = 0.96, 0.86, 0.84 and 0.83, samples designated S1, S3, S4, S5, respectively) have been investigated by DC magnetisation in field cooling and zero-field-cooling modes and EPR. DC magnetic susceptibility showed paramagnetic behavior of all samples in high-temperature range (T > 20 K) and transition to antiferromagnetic state at 16-18 K (depending on sample iron content). Additional magnetic freezing at 8 K was registered for S3-S5 samples containing larger amount of cobalt. The Curie-Weiss law in 100-300 K temperature range indicates that Co²⁺ is in the high-spin state (S = 3/2). From the parameters of the hysteresis loop observed for the samples it was calculated that 0.58% of all magnetic (Fe³⁺, Co²⁺) ions were involved in the ferromagnetic states. EPR spectra of the samples were recorded in high temperature range (T > 90 K). The temperature dependence of the spectral parameters (resonance field, linewidth, integrated intensity) suggested the Fe³⁺ high-spin ions coupled by antiferromagnetic interaction and clusters of ions play major role in EPR spectra.
4
Content available remote

Magnetic Resonance Study of MnO/ZnO Nanopowders

76%
Guskos N., Zolnierkiewicz G., Typek J., Sibera D., Narkiewicz U., Łojkowski W.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 6
1074-1079
EN
Fine particles n(MnO)/-(1-n)ZnO (n = 0.05 to 0.95) were prepared by wet chemistry method. According to X-ray diffraction analysis the obtained samples with n = 0.95, 0.90, 0.80, 0.70, 0.60 contained Mn_3O_4 and ZnMn_2O_4 phases, while samples with n = 0.05, 0.10, 0.20, 0.30, 0.40 and 0.50 contained ZnMnO_3 and ZnO phases. The mean crystalline size of ZnMnO_3 varied from 8 to 13 nm. The magnetic resonance investigations have been carried out at room temperature. Slightly asymmetric, broad and intense magnetic resonance line is recorded for all samples. The magnetic resonance spectra parameters showed marked differences depending on the composition index n. This could be explained by the variation of the magnetic susceptibility and a much slower evolution of spin relaxation, associated with the interaction of crystal field and superexchange interactions. Taking into account the values of magnetic resonance parameters, the investigated samples could be divided into two groups: these with the composition index n<0.50 and those with n>0.50. A detailed discussion of the magnetic properties of different phases in the n(MnO)/-(1-n)ZnO system is presented.
5
Content available remote

FMR Study of Temperature Dependence of Magnetic Properties of Nanocrystalline 0.90(Fe_2O_3)/0.10ZnO

76%
Guskos N., Glenis S., Zolnierkiewicz G., Typek J., Sibera D., Narkiewicz U.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 6
1070-1073
EN
The nanocrystalline mixed system 0.90(Fe_2O_3)/-0.10ZnO has been prepared by coprecipitation and calcination processes. The phase composition of samples was determined by X-ray diffraction. The studied nanocrystalline sample is dominated by phase Fe_2O_3 but very small amounts of ZnO and ZnFe_2O_4 phases were also identified. The ferromagnetic resonance investigations of the obtained sample have been carried out in the temperature range from liquid helium to room temperature. The asymmetrical and very intense magnetic resonance line was recorded at all temperatures. A significant shift of spectra towards lower magnetic fields with decreasing temperature was observed. A very good fitting by two Lorentzian functions has been obtained which suggested the existence of a strong anisotropic magnetic interaction. Some similarities in behaviour of ferromagnetic resonance parameters of the present sample and the 0.95Fe_2O_3Fe2O3/0.05ZnO sample were noticed but the parameters values were essentially different. The gradients Δ H_{r}/Δ T (where H_{r} is the resonance field), the broadening processes of the resonance lines as well as the line amplitudes were changing more intensely changing with temperature in comparison to sample 0.95Fe_2O_3Fe2O3/0.05ZnO. The following values Δ H_{r}/Δ T are obtained: 16.7(1) Gs/K and 20.7(1) Gs/K over the 60 K temperatures where below 40 K is 41.5(1) Gs/K and 56.0(1) Gs/K. The reorientation processes were more active at low temperatures for smaller concentrations of magnetic nanoparticles.
6
Publication available in full text mode
Content available

Charge Transfer and f-f Transitions Studied by Photoacoustic Spectroscopy of [R(NO_3)_2(PicBH)_2]NO_3 and [R(NO_3)_3(PicBH)_2] Complexes (R - Rare Earth Ion)

64%
Guskos N., Papadopoulos G., Majszczyk J., Typek J., Wabia M., Likodimos V., Paschalidis D., Tossidis I., Aidinis k.
Acta Physica Polonica A
|
2003
|
vol. 103
|
issue 2-3
301-313
EN
High-resolution photoacoustic spectra of trinitrato-bis[N-(2-pyridyl-methylene)-N'-benzoyl-hydrazine]R (III), (R = La, Ce, Pr), and binitrato-bis[N-(2-pyridylmethylene)-N'-benzoyl-hydrazine]R(III) nitrate (R=Y, Nd, Eu, Yb, Tb, Gd, Ho, Dy, Er) complexes, in the visual region, were studied for powder samples. Very intense photoacoustic spectra of various shapes were attributed to the intraligand transitions of the π → π* type located mainly on the C=N group and the n → π* transitions located on the carbonyl group. The intensity of these transitions essentially depends on the type of rare earth ions. The existence of f-f electron transitions could influence the relaxation processes, which play an important role in intensity determination of the above transitions. For many investigated samples the energy levels of excited states of rare earth ions were identified (f-f electron transitions). The radiation energy for some of the rare earth ions were compared with the d-d electron transitions of certain copper(II) organometallic complexes, which are very important in biogenic systems. The correlation between ions with localized and extended wave functions is suggested.
7
Publication available in full text mode
Content available

Magnetic Resonance and Dielectric Studies of a Nonlinear La_3Ga_{5.5}Ta_{0.5}O_{14} Single Crystal Doped with Erbium

64%
Bodziony T., Typek J., Orlowski M., Majszczyk J., Wabia M., Berkowski M., Ryba-Romanowski W., Guskos N., Likodimos V., Anagnostakis E.
Acta Physica Polonica A
|
2003
|
vol. 103
|
issue 2-3
315-322
EN
Single crystal of erbium doped La_3Ga_{5.5}Ta_{0.5}O_{14} grown by the Czochralski method have been investigated by electron paramagnetic resonance and dielectric spectroscopy methods. Dielectric permittivity ε measurements performed in 90-440 K temperature range have shown negligible dispersion for 1 kHz - 1 MHz frequencies and a Curie-Weiss type behaviour with C=47700 K andθ=-340 K. Electron paramagnetic resonance studies have revealed the presence of two different paramagnetic, monoclinic centres. The calculated g factor values are: g_1=1.449, g_2=11. 534, g_3=4.24 for the main M_1 centre and g_1=1.98, g_2=4.169, g_3=4.25 for the weaker M_2 centre. The temperature dependence of EPR line intensity for centre M_1 and M_2 is quite different - while lines attributed to M_1 could only be observed at low temperatures, below 20 K, lines of M_2 centre persisted up to 200 K. The M_1 centre is connected with Er^{3+} ion entering substitutionally into La^{3+} site, while M_2 is probably connected with 3d ions at the same site, unintentionally introduced into the material as an admixture.
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.