Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Refine search results

Journals help

  1. 90 Acta Physica Polonica A

  2. 1 Open Physics

Years help

  1. 2 2018

  2. 6 2017

  3. 2 2016

  4. 8 2015

  5. 15 2014

More...
Authors help

  1. 10 Nabiałek M.

  2. 7 Błoch K.

  3. 6 Bidulská J.

  4. 6 Bidulský R.

  5. 5 Actis Grande M.

More...
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 91

Number of results on page
first rewind previous Page / 5 next fast forward last

Search results

Search:
in the keywords:  75.50.-y
help Sort By:

help Limit search:
first rewind previous Page / 5 next fast forward last
1
Content available remote

Resistivity and Temperature Coefficient of Resistivity of the Fe/Zr Multilayer Films

100%
Luciński T., Stobiecki F.
Acta Physica Polonica A
|
1994
|
vol. 85
|
issue 2
443-447
EN
The resistivity (ρ) and temperature coefficient of resistivity (TCR) dependencies on modulation wavelength (λ) were examined in Fe/Zr multi-layer thin films. It was shown that the ρ(λ) and TCR(λ) behaviours can be explained on the basis of the assumption that the amorphous phase can be spontaneously formed during the deposition process. We found that the effective thickness of the amorphous phase was ≈2 nm per single interface.
2
Content available remote

Application of the Coupling Model to Magnetic After Effects in the Fe_{72}Co_{10}Nb_{6}B_{12} Amorphous Alloy

63%
Haneczok G., Kubik P., Madej Ł.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 1
396-398
EN
It was shown that magnetic reluctivity measured versus time after demagnetization for pre-annealed samples of the Fe_{72}Co_{10}Nb_6B_{12} amorphous alloy exhibits highly non-exponential behavior which can be described by the coupling model. The relaxation intensity and the coupling parameter describing correlation effects in free volume diffusion decrease with increasing 1 h annealing temperature indicating annealing out of free volume and formation of iron clusters in amorphous matrix.
3
Content available remote

Ultra-Fast Spin Dynamics in Diluted Magnetic Semiconductors

63%
Wilamowski Z., Buczko R., Karczewski G., Jantsch W.
Acta Physica Polonica A
|
1996
|
vol. 90
|
issue 5
969-972
EN
In nano-size antiferromagnetic systems a spatially inhomogeneous field leads to the formation of a staggered magnetization. Thereby the total magnetic moment does not change but the formation of a net magnetic moment at the border of the cluster leads to an energy gain. This type of magnetism is characterised by an ultra-fast dynamics. We suggest it is also responsible for the formation of the exciton magnetic polaron.
4
Publication available in full text mode
Content available

Design Rules for Manganites with Novel Magnetic and Electronic Properties

63%
Dabrowski B., Chmaissem O., Mais J., Kolesnik S.
Acta Physica Polonica A
|
2004
|
vol. 105
|
issue 1-2
45-56
EN
We have been systematically developing strategies for making new perovskite manganites with novel magnetic and electronic properties. This effort requires a two-fold approach: understanding the dependence of properties on chemical and structural factors and development of the ability to synthesize desired compounds. We show that, similar to other single valent 3d systems, the magnetic superexchange interactions in AMnO_3 manganites (A = rare or alkaline earth's) are dependent on the Mn-O-Mn bond angle which is a function of interatomic distances A-O and Mn-O. The local structural disorder on the A-site suppresses magnetic interactions. Recently, by comparing disordered (randomly mixed La/Ba) and ordered (forming Ba/La/Ba layers along the c-axes) perovskites we have demonstrated much more conspicuous effects of structural and charge disorder for mixed-valent manganites. We show that by stabilizing the ordered structure; i.e., by suppressing local structural and charge disorder on the A-site, a substantial increase in T_C from 340 to 365~K can be achieved. A similar control of order on the Mn-site was achieved for SrMn_{1-y}Ga_y O_{3-y/2} compounds near y=0.5, while SrMn_{1-y}Fe_yO_3 compounds are always randomly mixed. To achieve these compounds, we have been systematically developing special synthesis techniques for extending chemical composition ranges far beyond those previously achieved, developing rules for predicting which compositions should be possible to produce by these special techniques, and establishing methods for selectively ordering or disordering mixtures of metal atoms on the A- or Mn-sites.
5
Content available remote

Data Collapse of Energy Loss in Soft Magnetic Materials as a Way for Testing Measurement Set

63%
Sokalski K., Szczygłowski J.
|
|
issue 3
497-499
EN
Basing on the data collapse of the energy loss in soft magnetic materials, we propose a dimensionless measure of measurement set's uncertainty. The derived measure enables to compare uncertainty of different measurement sets and comparison of measurement data.
6
Content available remote

Quantum Phenomena in Small Antiferromagnets

63%
Wilamowski Z., Buczko R., Jantsch W.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
379-382
EN
We show that the most characteristic properties of mesoscopic antiferromagnets can be explained in terms of the response on a spatially inhomogeneous perturbation. This concept allows to explain the dynamic properties (quantum resonance, coherence and tunnelling rates) as well as static perturbations which, for increasing size of an antiferromagnet, leads to a transition from the quantum mechanical oscillating system to a classical antiferromagnet with well defined Néel vectors.
7
Content available remote

Local Structure and Magnetic Characteristics of FINEMET Alloys Substituted by Vanadium

63%
Brzózka K., Szumiata T., Gawroński M., Górka B., Sovák P., Pavlík G., Kolesár V.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
51-54
EN
Amorphous and nanocrystalline FINEMET-type alloys with vanadium addition up to 7 at% were investigated by the MÖssbauer spectroscopy and magnetic methods. The outcomes evidence alterations in grain structure, although the main effect is related to the changes in intergranular phase. This induces diminution of mean hyperfine field, saturation induction and Curie temperature as well as the increase in coercivity.
8
Content available remote

Magnetic Properties in Mn Pure Powder

63%
Szlaferek A., Baszyński J., Waplak S., Jóźwiak K.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
311-314
EN
The structural and magnetic properties of deformed powder of Mn obtained by mechanical grinding have been investigated using X-ray diffraction and magnetic measurements. The small values of ferromagnetic moment of Mn after grinding are attributed to the formation of a deformed phase at the surface of grains with enlargement of the interatomic spacings at the grains boundaries.
9
Content available remote

Influence of Biogenic Magnetic Nanoparticles on the Vesicular Transport

63%
Mikeshyna H., Darmenko Y., Gorobets O., Gorobets S., Sharay I., Lazarenko O.
Acta Physica Polonica A
|
2018
|
vol. 133
|
issue 3
731-733
EN
In this paper, the interaction forces are calculated between chains of BMNs on the cell membrane and vesicles (granules) inside the cell to identify the role of BMNs in vesicular transport in cell. For the first time, the forces arising between the vesicle and BMNs inside the cell were calculated, with vesicles being considered as effectively paramagnetic, paramagnetic and vesicles containing magnetic nanoparticles. The comparison was carried out of the forces arising between the vesicle and BMNs with the forces of the antigen-antibody, with the force necessary for the functioning of the magnetic tweezers and with the forces that molecular motors develop. It was determined that the forces of magnetic-dipole interaction of BMN with vesicles can significantly affect vesicular transport in cells.
10
Publication available in full text mode
Content available

Optimization of Soft Magnetic Properties in Fe-B and Fe-B-Si Amorphous Alloys Obtained by Melt Spinning Method

63%
Kwapuliński P., Stokłosa Z., Chrobak A., Rasek J., Haneczok G.
Acta Physica Polonica A
|
2002
|
vol. 102
|
issue 2
309-316
EN
In the present paper the process of optimization of soft magnetic properties have been studied by applying different experimental techniques (magnetic measurements, electric measurements, X-ray analysis, and high-resolution electron microscopy observations). It has been shown that an increase in magnetic permeability after optimization annealing can be mainly attributed to annealing out of microvoids.
11
Publication available in full text mode
Content available

Structural Relaxation and Crystallisation in Fe-Cr-Si-B and Fe-Cu-Cr-Si-B Amorphous Alloys

63%
Stokłosa Z., Rasek J., Kwapuliński P., Haneczok G., Pająk L.
Acta Physica Polonica A
|
2002
|
vol. 102
|
issue 2
273-281
EN
Structural relaxation, crystallisation and optimisation processes in soft magnetic amorphous alloys based on iron are examined by applying different experimental techniques: X-ray diffraction analysis, high-resolution electron microscopy, measurements of magnetic and electric properties (permeability, after-effect, resistivity). The presented results are discussed in terms of annealing out of microvoids, formation of a nanocrystalline phase and changes of effective magnetostriction constant.
12
Content available remote

Formula for Energy Loss in Soft Magnetic Materials and Scaling

63%
Sokalski K., Szczygłowski J.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 5
920-924
EN
Basing on scale invariance of considered system an improvement of the Bertotti formula for energy loss in soft magnetic materials has been achieved. Assumptions of the Bertotti theory were discussed and criticized. As an alternative to this theory a new approach basing on the scale invariance of complex systems has been presented. The generalized description of energy loss has been recently postulated by us in the form of the homogeneous function in a general sense which leads to a series expansion for the energy loss. On the basis of measurement data it has been proved that only two first terms of the series are relevant. New measurements of the energy loss in soft magnetic materials have been performed which confirms the scaling theory. The obtained formula enables very simple description of the energy loss in soft magnetic materials, taking into considerations wide ranges of frequency and magnetic induction. The revealed data collapse of energy loss enables comparison of energy losses data taken by different methods. This phenomenon also supplies new criterion for correctness of empirical data.
13
Content available remote

Specific Heat Study of PrNi_4Si

63%
Procházková K., Daniš S., Svoboda P.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
299-302
EN
Here we present the results of pilot polycrystalline study of PrNi_4Si. The X-ray study did not confirm the expected CaCu_5-type structure. Instead of this, the orthorhombic structure with the space group Cmmm was found. The zero-field specific heat was measured in the temperature range 2-300 K. The data were analyzed using the sum of the phonon, electronic, and magnetic contributions to specific heat, respectively. The magnetic part of the specific heat can be well described using the Schottky formula for the 9 crystal-field singlet levels of the pz3 H4 ground-state multiplet of the Pr^{3+} ion.
14
Content available remote

Analysis of the Nanocrystalline Phase Formation Process in Amorphous Fe-X-Si-B Alloys

63%
Stokłosa Z., Kwapuliński P., Rasek J., Ilczuk J., Lelątko J.
Acta Physica Polonica A
|
1996
|
vol. 89
|
issue 3
437-442
EN
The process of nanocrystalline phase formation, affecting magnetic properties, in amorphous Fe_{78}Si_{8}B_{14}, Fe_{76}Al_{2}Si_{8}B_{14}, Fe_{76}Cr_{2}Si_{8}B_{14} and Fe_{76}Mo_{2}Si_{8}B_{14} alloys has been studied in the paper. Investigations have been carried out using the electrical resistivity method, magnetic methods, transmission electron microscopy and X-ray diffraction. A nanocrystalline phase in the amorphous matrix has been obtained by isochronous or isothermal vacuum annealing. Phase composition of samples has been determined directly after manufacturing and after crystallization annealing on the basis of X-ray diffraction and electron diffraction. Transmission electron microscopy was used to determine phase morphology, dimensions of formed nanocrystalline phase and transition phase. Alloying elements have been found to affect changes of magnetic properties in amorphous and nanocrystalline states. For Fe_{76}Mo_{2}Si_{8}B_{14} alloys a significant increase in crystallization temperature, making difficult nanocrystalline phase growth and increase in thermal stability of magnetic permeability have been observed.
15
Content available remote

Measurement of Complex Permeability Using Short Coaxial Line Reflection Method

63%
Radonić V., Blaž N., Živanov L.
|
|
issue 5
820-824
EN
This paper describes realization of complex permeability determination for ferrite materials using short coaxial sample holder and vector network analyzer E5071B in frequency range between 300 kHz and 1 GHz. The design of coaxial high frequency sample holder is presented, the principle of measurement and calibration is shown. The extracting of complex permeability from S-parameters is managed based on accomplished formulas, user-friendly program for computer control has been written, and obtained results are explained in detail. In order to verify proposed method, the results of the measurement of NiZn ferrite samples, manufactured by MMG NeoSid, are compared with catalog characteristics.
16
Content available remote

Spontaneous Magnetostriction of Lu_2Fe_{17-x}Si_x

63%
Andreev A., Daniš S.
|
EN
Thermal expansion of Lu_2 Fe_{17-x}Si_x solid solutions was measured by X-ray powder diffraction. The magnetic ordering in all compounds within the homogeneity range (x≤3. 4) is accompanied by a large spontaneous volume magnetostriction distributed anisotropically over the principal axes of the hexagonal crystal structure. The volume effect ω_s in the ground state reaches 14.7×10^{-3} in Lu_2Fe_{17} and decreases monotonously to 8.9×10^{-3} at x = 3.4 following the reduction of magnetic moment. Despite still large ω_s, the Invar behavior observed in Lu_2Fe_{17} changes to a positive thermal expansion for x >1 due to increasing Curie temperature.
17
Publication available in full text mode
Content available

On Magnetization Reversal in Hard Magnetic Sm-Fe-N Permanent Magnets

63%
Pawlik P., Wysłocki J., Baran M.
|
EN
The investigations were carried out on Sm-Fe-N permanent magnets produced by reactive diffusion method. The magnets consist of hard magnetic phases: Sm_2Fe_{17}N_{0.86} and SmFe_5 and soft magneticα-Fe phase. From the comparison of experimentally determined angular dependence of coercive field with appropriate theoretical predictions and from the dependence of coercive field on the external magnetic field determined from the minor hysteresis loops, it was stated that magnetization reversal process in Sm-Fe-N magnets is controlled by the nucleation of reversed domains process.
18
Content available remote

Localized Spin Relaxation Due To Coupling To Effective Mass States

63%
Wilamowski Z., Dmochowski J., Jantsch W.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 5
1055-1058
EN
The EPR of residual Mn in CdF_{2} doped with Y, In and Ga is investigated. Although these donors are barely seen in EPR, they manifest themselves by a new effect: a drastic resonant reduction in the longitudinal relaxation rate of Mn which occurs only if the Zeeman splitting of the two subsystems coincide. In this situation, the saturation of those of the six Mn hyperfine lines is weakened which coincide with the shallow donor resonance.
19
Content available remote

Magnetic Properties and Giant Magnetoimpedance in Amorphous and Nanocrystalline Microwires

51%
Talaat A., Zhukova V., Ipatov M., Blanco J., Churyukanova M., Kaloshkin S., Kostitcyna E., Shuvaeva E., Gonzalez-Legarreta L., Hernando B., Zhukov A.
|
|
vol. 126
|
issue 1
146-147
EN
We studied magnetic properties and GMI effect of Finemet-type FeCuNbSiB microwires. We observed that GMI effect and magnetic softness of microwires produced by the Taylor-Ulitovski technique, can be tailored by either controlling magnetoelastic anisotropy of as-prepared FeCuNbSiB microwires or controlling their structure by heat treatment or changing the fabrication conditions. GMI effect has been observed in as-prepared Fe-rich microwires with nanocrystalline structure.
20
Publication available in full text mode
Content available

Magnetic Resonance Imaging at Low Magnetic Field Using Hyperpolarized ^3He Gas

51%
Suchanek M., Cieślar K., Pałasz T., Suchanek K., Dohnalik T., Olejniczak Z.
Acta Physica Polonica A
|
2005
|
vol. 107
|
issue 3
491-506
EN
A low magnetic field magnetic resonance imaging system for small animal lung imaging using hyperpolarized ^3He gas is presented. The hyperpolarized ^3He gas at 1 mbar pressure and 30% polarization is obtained by the metastability exchange optical pumping technique. The magnetic resonance imaging unit is based on a permanent magnet of open geometry, built from a new generation Nd-B-Fe magnetic material. It produces the magnetic field of 88 mT with homogeneity better than 50 ppm in the 10 cm diameter sphere, after application of passive shimming. The magnetic field gradients of 30 mT/m are generated by a set of biplanar, actively shielded gradient coils. The first ^1H images of various biological objects, as well as ^3He images of the rat lung in vivo obtained in the described system are shown. In terms of sensitivity and resolution, the technique is superior to conventional ^1H magnetic resonance imaging, and offers great possibilities in early diagnosis of lung diseases.
first rewind previous Page / 5 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.