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1
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Microstructure and Magnetic Properties of the Nanocrystalline Fe-Co-Zr-Ti-Pr-B Alloys

100%
Pawlik P.
Acta Physica Polonica A
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2008
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vol. 113
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issue 1
315-318
EN
Investigation of the Fe_{60}Co_{13}Zr_1Ti_3Pr_9B_{14} alloy 1 mm diameter rods and 3 mm outer diameter tubes showed a possibility of processing nanocrystalline magnets by direct quenching. It was revealed that the low temperature annealing of the tube samples at 573 K/10 min resulted in an improvement of the intrinsic coercivity that reaches≈1260 kA/m, which was a similar value to that measured for thin ribbon annealed at 973 K/10 min. The X-ray diffraction analysis revealed that the hard magnetic Pr_2(Fe, Co)_{14}B was the single crystalline phase that precipitated during rapid solidification process of the tube and rod samples and during devitrification annealing of the ribbons.
2
Content available remote

Uncertainty Evaluation in Modelling of Acoustic Phenomena with Uncertain Parameters Using Interval Arithmetic

64%
Batko W., Pawlik P.
Acta Physica Polonica A
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2012
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vol. 121
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issue 1A
A-152-A-155
EN
Uncertainty assessment in modelling of acoustic phenomena with uncertain parameters using interval arithmetic on the example of the reverberation time estimation, are presented in the paper. The application of the classical interval analysis formalism as well as its expansions are shown. Statistical methods of estimation of the reverberation time are based on parameters, which are related, among others, to the geometry of the analysed room, characteristics of sound absorption, and interior transmission. Values of these parameters are usually difficult to determine, which has a significant influence on the modelling result. The interval analysis allows to determine the variability interval of the parameter being estimated. The authors determined the influence of the input parameters uncertainty on the estimated reverberation time, calculated according to the Sabine, Eyring-Norris and Millington-Sette formulae. The uncertainty analysis was performed for the literature data, related to the reverberation time calculations of the room of a certified acoustics.
3
Content available remote

New Method of Uncertainty Evaluation of the Sound Insulation of Partitions

64%
Batko W., Pawlik P.
Acta Physica Polonica A
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2013
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vol. 123
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issue 6
1012-1015
EN
The analysis of uncertainty related to evaluation of sound insulation of partitions performed according to standard solutions recommended in The Guide to the Expression of Uncertainty in Measurement (GUM) by ISO/IEC-1998 and according to the new method based on the interval analysis - is presented in the paper. Both methods are compared and their application advantages presented. Limitations of the current solutions based on the law of propagation of uncertainty are shown. The method of the estimate derivation for the sound insulation based on interval arithmetic related to the measurement data is presented. The influence of the input parameters uncertainty on the calculation results of the sound insulation of partitions is determined. The considerations are illustrated by numerical examples.
4
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Content available

Dependence Of The Structure And Magnetic Properties Of Cast Plate-Shaped Nd60Fe30Al10 Samples On Their Thickness

52%
Kaszuwara W., Michalski B., Latuch J., Pawlik P.
Archives of Metallurgy and Materials
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2015
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issue 3
5
Publication available in full text mode
Content available

Mechanism of Rotational Hysteresis Energy in Sm-Fe-N Permanent Magnets

52%
Pawlik P., Wysłocki J., Dziliński K.
Acta Physica Polonica A
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2002
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vol. 101
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issue 2
267-277
EN
Investigations were carried out on Sm-Fe-N permanent magnet produced by the reactive diffusion method with different grain sizes (from 8.6 to 0.97μm). The rotational hysteresis energy has been measured as a function of the applied field. The proposed model of rotational hysteresis energy is in good agreement with the experimental results. It is shown that the magnetization reversal process in Sm-Fe-N magnet is controlled by the nucleation of reversed domains.
6
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Magnetization Reversal Processes in Pr-Fe-B-type Nanocrystalline Magnets

52%
Pawlik K., Pawlik P., Kaszuwara W., Wysłocki J.
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vol. 126
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issue 1
186-187
EN
The magnetization reversal processes in magnets derived from rapidly solidified Pr_{9}Fe_{52}Co_{13}Zr_{1}Nb_{4}B_{21} alloy samples were studied by analysis of minor hysteresis loops and recoil curves. The studies were carried out on suction-cast 1 mm diameter rod, 1 mm thick plate, 3 mm outer diameter (o.d.) tube and melt-spun ribbon samples subjected to annealing at 983 K for 5 min. The X-ray diffraction analysis has shown multiphase constitution of the samples. Structural and magnetic studies indicated that the initial state of microstructure and phase composition affects the magnetization reversal processes in annealed samples due to a variation of microstructure in samples of various shapes. Magnetic studies allowed estimation of the mean values of nucleation and pinning fields that control the magnetization reversal processes.
7
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Glass Forming Abilities and Crystallization Process in Amorphous Pr-Fe-Co-Zr-Nb-B Alloys of Various B Content

52%
Pawlik K., Pawlik P., Kaszuwara W., Wysłocki J.
Acta Physica Polonica A
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2017
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vol. 131
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issue 4
979-981
EN
The influence of boron contents on the glass forming abilities and magnetic properties of melt-spun ribbon samples produced from Pr₉Fe_{50+x}Co₁₃Zr₁Nb₄B_{23-x} (x=0, 2, 5, 8) alloys, were investigated. For all compositions, the rapidly solidified samples were fully amorphous, which was confirmed by X-ray diffractometry and the Mössbauer spectroscopy. Differential scanning calorimetry and differential thermal analysis studies revealed good glass forming abilities for all investigated specimens and allowed to determine thermal stability parameters of the amorphous phase. For all alloy ribbons, very large supercooled liquid region before crystallization ΔT_x reaching 100 K was measured. The Kissinger plots were constructed to determine the activation energies for crystallization. Annealing of specimens at temperatures ranging from 923 K to 1033 K for 5 min resulted in significant change of the phase constitution. The X-ray diffractometry studies have shown presence of hard magnetic Pr₂(Fe,Co)₁₄B and paramagnetic Pr_{1+x}Fe₄B₄ phases. Furthermore, with the increase of B contents in the alloy composition crystallization of α-Fe phase occurs at wider range of the annealing temperature. Anomaly of both thermal and magnetic properties was observed for the Pr₉Fe₅₂Co₁₃Zr₁Nb₄B₂₁ alloy ribbons.
8
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The Bulk Glass Forming Ability and Magnetic Properties of Pr_9Fe_{50 + x}Co_{13}Zr_1Nb_4B_{23 - x} (x = 0, 2, 5, 8) Alloys

52%
Pawlik K., Pawlik P., Wysłocki J.
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issue 5
900-902
EN
In the present study the rapidly quenched Pr_9Fe_{50 + x}Co_{13}Zr_1Nb_4B_{23 - x} (x = 0, 2, 5, 8) alloy samples produced in a form of 100 mm^2 plate of various thicknesses were investigated. The X-ray diffraction revealed changes in the phase constitution of as-cast samples depending on the alloy composition and plate thickness. The presence of hard magnetic Pr_2(Fe,Co)_{14}B phase was observed in 0.5 mm thick plates of the x = 8 alloy, while fully glassy structure was shown in 0.5 mm thick plates of the x = 0 alloy. It was shown in the present paper that magnetic properties of annealed samples originated from different microstructure of as-cast samples.
9
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Determining the Distribution of Stochastic Impulses Acting on a High Frequency System through an Analysis of Its Vibrations

52%
Jabłoński M., Ozga A., Korbiel T., Pawlik P.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
977-980
EN
The motion of an oscillator with damping excited by impulses has the form $ξ_t = \frac{1}{\sqrt{a^2 - b^2}} \sum_{0
10
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Magnetization Reversal Processes in the Nanocrystalline Fe-Co-Zr-Ti-Pr-B Magnets

52%
Pawlik K., Pawlik P., Wysłocki J., Kaszuwara W.
Acta Physica Polonica A
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2008
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vol. 113
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issue 1
39-42
EN
Magnetization reversal processes in the magnets derived from the Fe_{60}Co_{13}Zr_1Ti_3Pr_9B_{14} alloy were investigated. It was shown that the processing technique affects the magnetization reversal processes. For the nanocrystalline ribbon samples pinning of the domain walls arises at low external magnetic fields while nucleation of reversed domains occurs at higher fields. However, the nucleation fields are lower than the pinning fields for the nanocrystalline rod and tube samples produced by suction-casting technique.
11
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Influence of Annealing Conditions on Magnetic Properties and Phase Constitution of the Rapidly Solidified Fe₆₅Pr₉B₁₈W₈ Alloy Ribbons

52%
Filipecka K., Pawlik P., Kozdraś A., Filipecki J.
Acta Physica Polonica A
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2016
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vol. 129
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issue 2
185-187
EN
In the present work, the influence of annealing conditions on magnetic properties and phase constitution of the rapidly solidified Fe₆₅Pr₉B₁₈W₈ alloy ribbons, were investigate. Samples were prepared by arc-melting of high purity constituent elements under the Ar atmosphere. Ribbons were obtained by melt-spinning technique under low pressure of Ar. The ribbons in as-cast state had amorphous structure and soft magnetic properties. Heat treatment, carried out at various temperatures (from 923 K to 1023 K) for 5 min, resulted in an evolution of the phase constitution that caused changes in magnetic properties of the alloy. The crystallization behavior was studied using differential scanning calorimetry and X-ray diffractometry. The room temperature magnetic properties were determined from hysteresis loops measured by VSM magnetometer in the external magnetic field up to 2 T.
12
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Content available

Magnetic Properties of the Nanocrystalline Nd9.6Fe64.32Nb4B22.08 Alloy Ribbons

52%
Szwaja M., Pawlik P., Wysłocki J., Gębara P.
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issue 1
13
Publication available in full text mode
Content available

Influence of Heat Treatment on Magnetic Properties of Nanocrystalline Nd9Fe84Zr1B6 Ribbons Received by Rapid Solidification Method

52%
Dośpiał M., Ceglarek A., Płusa D., Pawlik P.
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issue 1
14
Content available remote

Measurements of Magnetocaloric Effect in LaFe_{11.14}Co_{0.66}Si_{1.2-x}Al_{x} (x=0.1, 0.2, 0.3) Alloys

52%
Gębara P., Pawlik P., Michalski B., Wysłocki J.
Acta Physica Polonica A
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2015
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vol. 127
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issue 2
576-578
EN
In the present work, phase constitution and thermomagnetic properties of LaFe_{11.14}Co_{0.66}Si_{1.2-x}Al_{x} (where x = 0.1, 0.2, 0.3) alloys were investigated. Ingot samples were obtained by arc-melting under the low pressure of Ar atmosphere. Subsequently samples were annealed at 1323 K for 15 days. X-ray diffraction of all samples revealed coexistence of two crystalline phases dominant La(Fe,Si)_{13}-type and minor bcc α -Fe. Furthermore, the magnetic measurements at various temperatures allowed to study the Curie temperature, magnetic entropy changes and relative cooling power.
15
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Content available

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

52%
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.
16
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Phase Structure and Heat Generation in the Co-Precipitated Magnetite Nanoparticles

52%
Pawlik P., Pruba M., Pawlik K., Kotynia K.
Acta Physica Polonica A
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2017
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vol. 131
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issue 5
1217-1221
EN
In the present studies the phase structure and magnetic ordering of magnetite nanoparticles were investigated. The powder samples were obtained by co-precipitation from Fe(III) and Fe(II) salts. SiO₂ coating was performed using the modified Stöber process. X-ray diffraction studies revealed presence of the only one Fe₃O₄ crystalline phase both for the non-coated and SiO₂-coated samples. The Mössbauer studies have shown differences in shapes of measured spectral lines for Fe₃O₄ particles subjected to the Stöber process and non-coated particles. The heating efficiency was measured for glycerol dispersed nanoparticles. The analysis have shown changes in specific loss power depending on the concentration of the nanoparticles and amplitude of alternating magnetic field.
17
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The Structural Stability of Soft Magnetic Fe-Co-Zr-W-B Metallic Glasses Investigated by the in-situ X-ray Diffraction

46%
Michalik S., Bednarcik J., Pawlik P., Matija R., Sovak P.
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vol. 126
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issue 1
66-67
EN
The atomic structure of as-prepared Fe_{61}Co_{(14-x)}Zr_{5}W_{x}B_{20} (x=1, 2 and 4) ribbon samples and their thermal stability were investigated by in-situ high-energy X-ray diffraction experiments. It was observed that higher W concentration causes the tiny shift of the main peak of the reduced atomic pair distribution function to higher values of interatomic distances and increases the coefficient of volume thermal expansion. The crystallization process occurs in two steps and is qualitatively the same for all studied specimens. Firstly the Fe_{23}B_{6} phase is created and later is transformed to other types of borides together with the creation of a Fe-based phase.
18
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Influence of Nb Addition on Magnetic Properties of the Nanocrystalline (Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ (where x = 1, 2, 4) Alloy Ribbons

46%
Szwaja M., Pawlik K., Pawlik P., Gębara P., Michalski B.
Acta Physica Polonica A
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2015
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vol. 127
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issue 2
623-625
EN
In the present work the magnetic properties and phase constitution of (Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ (where x = 1, 2, 4) alloys in the form of ribbons were investigated. The base alloys were prepared by arc-melting the high purity elements with pre-alloyed Fe-B under an Ar atmosphere. The ribbon samples were obtained by controlled atmosphere melt-spinning technique. In order to generate the nanocrystalline microstructure and hard magnetic properties, samples were annealed at various temperatures (from 923 K to 1023 K) for 5 min. The aim of the present work was to determine the influence of Nb admixture and annealing conditions on the phase constitution and magnetic properties.
19
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Effect of Ga Addition on Structure and Magnetic Properties of the LaFe_{11.14}Co_{0.66}Si_{1.2-x}Ga_{x} (x=0.1, 0.2, 0.3) Alloys

46%
Gębara P., Pawlik P., Michalski B., Wysłocki J., Kotynia K.
Acta Physica Polonica A
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2015
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vol. 128
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issue 1
87-90
EN
In the present work, the phase constitution and magnetic properties of the LaFe_{11.14}Co_{0.66}Si_{1.2-x}Ga_{x} (where x=0.1, 0.2, 0.3) alloys, were investigated. It was revealed that increase of Ga content in the alloy composition causes the rise of lattice parameter of the La(Fe,Si)_{13}-type phase, which causes increase of the Curie temperature. However, the increase of Ga addition leads to decrease of magnetocaloric effect.
20
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Structural and Magnetocaloric Study οf the LaFe_{11.0}Co_{0.8}(Si_{0.4}Al_{0.6})_{1.2} Alloy

46%
Gębara P., Pawlik P., Škorvánek I., Marcin J., Wysłocki J.
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issue 5
910-912
EN
In this study, we have investigated the microstructure and magnetic entropy change of annealed LaFe_{11.0}Co_{0.8}(Si_{0.4}Al_{0.6})_{1.2} alloy in a form of bulk samples and melt-spun ribbons. The bulk samples were annealed at 1323 K for 20 and 49 days and the maximum values of the magnetic entropy change | ΔS_M | obtained after the change of external magnetic field from 0 to 5 T reached 7.5 J kg^{-1} K^{-1} and 7.7 J kg^{-1} K^{-1}, respectively. For the melt-spun ribbon annealed at the same temperature for 1 h, the maximum value of | ΔS_M | reaches 4.5 J kg^{-1} K^{-1}. The temperature corresponding to the maximum entropy change increased from 292 K for bulk samples to 295 K for melt-spun ribbons. The lower values of the magnetic entropy change in the melt-spun LaFe_{11.0}Co_{0.8}(Si_{0.4}Al_{0.6})_{1.2} are attributed to the presence of higher volume fraction of the secondary bcc-Fe phase in the ribbon samples.
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