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: 20

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

Magnetism in NdMnO_{3+δ} Studied by the Single Crystal Neutron Diffraction

100%
Mihalik M., Mihalik M., Maťaš S., Vavra M.
|
|
vol. 126
|
issue 1
284-285
EN
We present the single crystal neutron diffraction experiment performed on the NdMnO_{3+δ} compound. The aim of the experiment was to study/revisit the magnetic structure of the compound. We have confirmed the ordering of Mn sublattice below T_{N}=85.5 K and confirmed that the Nd sublattice orders below T_{1} ≈ 20 K with Nd moments aligned parallel to the b-axis.
2
Content available remote

Magnetic Properties of La_{0.8}K_{0.2}MnO_{3} Nanoparticles

76%
Mihalik M., Zentková M., Briančin J., Fitta M., Mihalik M., Lazúrová J., Vavra M.
|
|
vol. 126
|
issue 1
312-313
EN
Magnetic properties of La_{0.8}K_{0.2}MnO_{3} have been studied on nanoparticles prepared by glycine-nitrate method. Crystal structure and particles size were modified by heat treatment. Crystal structure changes from orthorhombic (space group Pbma) to rhombohedral (space group R-3c) after annealing at 600°C/2 hours. The average size of particle varies with annealing from about 30 nm to 135 nm. The Curie temperature T_{C} and the saturated magnetization μ_{s} increase with annealing. The exchange bias effect was observed on samples with particles size smaller than 60 nm.
3
Content available remote

Magnetic Properties of (Cu_{x}Mn_{1-x})_3[Cr(CN)_6]_2·zH_2O Complexes

76%
Vavra M., Antoňák M., Jagličić Z., Mihalik M., Mihalik M., Csach K., Zentková M.
|
|
issue 5
998-999
EN
Magnetization measurements were performed on the (Cu_{x}Mn_{1-x})_3[Cr(CN)_6]_2·zH_2O molecule-based magnets where x=0.0, 0.2, 0.25, 0.3, 0.35 0.4, 0.6, 0.8 and 1.0. Both the Curie temperature and saturated magnetization at first decrease with increasing value of x reaching the minimal value of T_{C} = 49.7 K and 0.17 μ_{B} for x=0.2 and then increase with substitution. The pronounced hysteretic behavior between zero-field cooled and field cooled regimes was observed for all samples. Magnetization changes the sign of magnetic polarization in zero-field cooled magnetization curve at the compensation temperature T_{comp} = 16 K for sample with x = 0.4. Our results indicate that the system behaves as mixed-ferri-ferromagnetic system.
4
Content available remote

Characterization of New U-Ni-X₂ Splats and Study of their Physical Properties

64%
Molčanová Z., Mihalik M., Mihalik M., Reiffers M., Džubinská A., Huráková M., Kavečanský V., Paukov M., Havela L.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 4
994-996
EN
We explored the crystal structure, magnetic, and transport properties of UNiX₂ (X = Ge, Si) materials, which were prepared by a conventional metallurgical technique and by rapid solidification - splat cooling. The UNiSi₂ splat is mostly single phase, containing only small traces of a minority phase. Magnetic and electrical properties of the splat resemble properties of samples, which were prepared by conventional methods, exhibiting a ferromagnetic transition at about 91 K and similar temperature dependence of resistivity. The coercive field of μ₀H_c=4.25 T is much enhanced due to the magnetic anisotropy introduced by the sample preparation technique. The Barkhausen jumps were observed on the hysteresis loop. Magnetization of the sample does not saturate in fields up to μ₀H=9 T. The phase structure of UNiGe₂ splat is not completely solved and will be subject of our study in future. Our preliminary results indicate the presence of completely new phase with tetragonal crystal structure and antiferromagnetic ordering below 54 K.
5
Content available remote

Magnetic Properties of NdFe_{0.9}Mn_{0.1}O_{3}

64%
Zentková M., Lazúrová J., Kováč J., Mihalik M., Mihalik M., Briančin J., Fitta M., Kusigerski V.
|
|
vol. 126
|
issue 1
306-307
EN
In our paper we study effect of Mn for Fe substitution on magnetic properties of NdFe_{x-1}Mn_{x}O_{3} compounds for x=0 and 0.1, which have been grown by the OFZ technique. The Néel temperature decreases from T_{N1}=691 K to T_{N1}=621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x=0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at T_{sh} to higher temperatures. Another anomaly is generated by doping at T_{max}=11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.
6
Content available remote

Magnetic Properties of La_{0.85}Ag_{0.15}MnO_{3} Nano-Powders Under Pressure

64%
Antoňák M., Mihalik M., Zentková M., Mihalik M., Vavra M., Lazúrová J., Fitta M., Balanda M.
|
|
vol. 126
|
issue 1
296-297
EN
In our paper we present effect of pressure on magnetic properties of La_{0.85}Ag_{0.15}MnO_{3} nanopowders prepared by glycine-nitrate method. The particle size and crystal structure were modified by heat treatment. The average size of particle varies from about 25 nm for as prepared sample to 60 nm for annealed sample. Crystal structure changes from orthorhombic to rhombohedral after annealing at 600 °C/2 hours. The Curie temperature increases with annealing and is more than doubled after annealing at 600 °C/2 hours. The exchange bias phenomenon was observed in samples with orthorhombic crystal structure with average particle size of about 25 nm. Pressure effect on the Curie temperature T_{C}, saturated magnetization μ_{s} and exchange bias field H_{E} is negligible in this case. In the case of the samples with rhombohedral structure, T_{C}, μ_{s} and remnant magnetization μ_{r} increase with pressure; the coercive field decreases with pressure.
7
Content available remote

Anisotropy of Susceptibility and Optical investigation of the Antiferromagnetic phase Transition in U_{1-x}Ce_{x}Ru_{2}Si_{2}

63%
Mihalik M., Maťaš S., Macko D., Timko M., Menovsky A. A.
Acta Physica Polonica A
|
1997
|
vol. 91
|
issue 2
351-354
EN
Temperature dependence of magnetic susceptibility of U_{1-x}Ce_{x}Ru _{2}Si_{2} single crystals (x=0, 0.025, 0.05, 0.075) has been studied at temperatures from 4.2 K up to room temperature and in magnetic fields applied along and perpendicular to the c-axis. The attention was paid to anomalies connected with the antiferromagnetic phase transition, which are present in crystals with x≤0.05. Far-infrared measurements of U_{0.99}Ce_{0.01} Ru_{2}Si_{2} single crystal have been studied for the first time. The measurements support the assumption that the origin of magnetic ordering in U_{0.99}Ce_{0.01}Ru_{2}Si_{2} is the same as in heavy-fermion superconductor URu_{2}Si_{2} and can be interpreted as being due to a spin-density-wave gap.
8
Content available remote

Valence Band and Core Levels of Ce_5Ni_2Si_3 Crystal Studied by X-ray Photoemission Spectroscopy

63%
Toliński T., Kowalczyk A., Chełkowska G., Mihalik M., Timko M.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
327-330
EN
The crystal of Ce_5Ni_2Si_3 was prepared by the Czochralski method. The X-ray photoemission spectroscopy was measured for the valence band and the core levels. Based on the Ce(3d) doublet and its satellites a small value of the hybridization parameter of the f-states with the conduction electrons Δ=4 meV and the f-occupancy n_f close to 1 were found. X-ray photoemission spectroscopy shows that the region between 0 and 3 eV is predominated by the Ni(3d) and Ce(4f) peaks. Some features of the multiplet structure of the Ce(4f) states are also visible close to the Fermi level.
9
Content available remote

Magnetic and Transport Properties of La_{0.67}Pb_{0.33}(Mn_{1-x}Co_x)O_3

55%
Mihalik M., Kavečanský V., Maťaš S., Zentková M., Ammer J., Kellner K., Gritzner G.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
251-254
EN
Detailed studies of temperature dependences of magnetization, AC susceptibility and electrical resistance were performed on La_{0.67}Pb_{0.33}(Mn_{1-x}Co_x)O_3 ceramics with x = 0.01 and 0.1. Typical features of both compounds are the hysteretic behavior between the zero-field-cooled magnetization regime and the field-cooled magnetization regime, a very weak field dependence of a maximum in zero-field-cooled magnetization and practically no frequency dependence of the peak in AC susceptibility χ"(T). Anomalies in the electrical resistance connected with the ferromagnetic transition at T_C, the insulator-metal transitions at T_p and the re-entrant metal-isolator transition at T* are field dependent pointing to magnetic origin of these transitions. Colossal magnetoresistance was observed in both compounds.
10
Content available remote

Effect of Pressure on Magnetic Properties of Hexacyanochromates

55%
Mitróvá Z., Maťaš S., Mihalik M., Zentková M., Arnold Z., Kamarád J.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
469-472
EN
We present the study of pressure effect on magnetic properties of TM^{2+}_3[Cr^{III}(CN)_6]_2·nH_2O ferrimagnets and ferromagnets (TM = Cr and Co) under pressures up to 0.9 GPa. Applied pressure strengthens super-exchange interaction in Cr^{2+}-prussian blue analogues with dominant antiferromagnetic interaction J_{AF} leading to increase in the Curie temperature T_C (ΔT_c/Δp = 29.0 K/GPa) and reduces T_C of Co^{2+}-prussian blue analogues with dominant ferromagnetic interaction J_F (ΔT_c/Δp = -1.8 K/GPa). The rise of J_{AF} interaction is attributed to the enhanced value of the single electron overlapping integral S. On the other hand, the applied pressure slightly affects bonding angles between magnetic ions mediated by the cyano-bridge and reduces the strength of magnetic coupling. Changes of the magnetization curve with pressure can be attributed to changes of magnetic anisotropy. The reduction of magnetization with pressure observed on Cr^{2+}-prussian blue analogues can be explained by pressure induced transition from Cr^{2+} high spin state to Cr^{2+} low spin state. All pressure induced changes are reversible.
11
Content available remote

Magnetism of Nanoparticle La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3 under Applied Hydrostatic Pressure

55%
Kusigerski V., Perovic M., Mrakovic A., Blanusa J., Mihalik M., Zentkova M., Spasojevic V.
|
|
issue 5
811-812
EN
Nanoparticle La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3 with the average particle size of 10 nm was mechanochemically synthesized in the single-step procedure. Temperature and field dependences of magnetization were recorded under both ambient and applied hydrostatic pressure up to 0.47 GPa. At ambient pressure, two magnetic transition points were observed: one of the spin-glass like type at the temperature T_{f} ≈ 34 K, and ferro-to-paramagnet transition at T_{C} ≈ 51 K. Under the applied pressure magnetic parameters gradually changed: (i) both T_{C} and T_{f} were lowered with the increase in pressure; (ii) both high field magnetization M_{5T} and remanent magnetization M_{Rem} decreased with pressure; (iii) coercivity H_{C} increased with pressure. The obtained results show that magnetism of a nanoparticle system with high degree of intrinsic disorder diminishes with the applied pressure that is in compliance with the effect of the increased cationic disorder ("internal pressure") in bulk manganites.
12
Content available remote

Magnetic Properties of Milled and Thermal Relaxed YBa_{2} (Cu_{1-x}Fe_{x})_{3}O_{y}

55%
Timko M., Kováč J., Sargánková I., Zentková M., Mihalik M., Maťaš S., Čiasnohová A.
Acta Physica Polonica A
|
1997
|
vol. 91
|
issue 2
355-358
EN
The influence of the mechanical milling and subsequent thermal relaxation on magnetic and superconducting behaviour of YBa_{2}(Cu_{1-x}Fe _{x})_{3}O_{y} system has been studied. Two methods of heat treatment were used: Set I - slow cooling from 980°C in flowing O_{2} and Set II - reducing at 770°C in flowing Ar_{2} followed by reoxidation in flowing O_{2} below 400°C. The transition to superconductivity, diamagnetic response, critical current density and the effective magnetic moment in the normal state have been estimated. Our measurements indicate that the reducing atmosphere preparation is less detrimental on superconducting properties. The results are discussed in terms of occupancy Cu sites by Fe and redistribution of oxygen atoms.
13
Content available remote

Electronic States of UNi_2 from Photoemission Spectroscopy

55%
Zalecki R., Kołodziejczyk A., Kim-Ngan N., Adamska A., Kowalczyk A., Toliński T., Mihalik M.
|
EN
We measured the angle-resolved ultraviolet and X-ray photoemission spectra of UNi_2 single crystal. The valence band angle-resolved ultraviolet photoemission spectra were compared to the accessible band structure calculations. For UNi_2 the lowest binding energy strong emission at about -0.1 eV comes from U 5f states and overlaps with the Fermi edge. A small feature at -0.6 eV was ascribed also to U 5f electrons with more localised character. The higher-energy two-peak structure at about -1.2 eV and -2.1 eV comes from Ni 3d states. X-ray photoemission spectroscopy shows the standard two-line spin-orbit splitting of the Ni 2p states and of the U 4f states. Some hybridisation of the Ni 3d and U 5f state was observed in the spectra. The pronounced satellites to the Ni 2p and 3p states, associated with the on-site Coulomb repulsion and other electron correlation energies, were observed.
14
Content available remote

Exchange Bias Effect in NdFeO₃ System of Nanoparticles

46%
Vavra M., Zentková M., Mihalik M., Mihalik Jr. M., Lazúrová J., Girman V., Perovic M., Kusigerski V., Roupcova P., Jaglicic Z.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 4
869-871
EN
We study the effect of nanometric size on the crystal structure, magnetic environment of iron and magnetization in NdFeO₃ system of nanoparticles. The average particle size of NdFeO₃ nanoparticles increases with annealing at 600°C from about 15 nm to 40 nm. The smallest particles on annealed sample have size approximately 30 nm and typically have character of single crystalline samples. All samples adopt orthorhombic crystal structure, space group Pnma with lattice parameters a =5.5817 Å, b=7.7663 Å and c =5.456 Å for as prepared sample. The presence of superparamagnetic particles was indicated by the Mössbauer measurements. The reduction of dimensionality induces a decrease of T_{N1} from 691 K to 544 K. The shift of magnetic hysteresis loop in vertical and horizontal direction was observed at low temperatures after cooling in magnetic field. We attribute such behaviour to exchange bias effect and discuss in the frame of core-shell model.
15
Content available remote

Effect of the Jahn-Teller Distortion on Double Exchange Interaction in La_{0.8}K_{0.2}MnO₃ Nanoparticles

46%
Mihalik M., Zentková M., Vavra M., Mihalik Jr. M., Lazúrová J., Girman V., Konieczny P., Fitta M., Il'kovič S.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 4
875-877
EN
Electric resistance and effect of hydrostatic pressure on magnetic properties has been studied on the La_{0.8}K_{0.2}MnO₃ nanoparticles. Magnetic phase transition is affected by pressure only slightly, the Curie temperature T_{C} decreases with the rate of -1.02 K/GPa, on samples with orthorhombic structure where the Jahn-Teller distortion of lattice is large. On the other hand, T_{C} increases with the rate of 20.1 K/GPa on samples with rhombohedral structure, where the Jahn-Teller distortion of lattice is absent. Insulator type of electrical resistance is characteristic feature of sample with large Jahn-Teller distortion of lattice and insulator-metal transition was observed on samples where the Jahn-Teller distortion is negligible. Our results are in line with theoretical calculation predicting that double exchange interaction is suppressed by the Jahn-Teller distortion.
16
Content available remote

Magnetic Relaxation and Memory Effect in Nickel-Chromium Cyanide Nanoparticles

46%
Zentko A., Kavečanský V., Mihalik M., Maťaš S., Mitróová Z., Zentková M., Maryško M., Jagličić Z.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
511-514
EN
The low temperature dynamics of a magnetic nanoparticle system Ni_3[Cr(CN)_6]_2 with an average nanoparticles size of 4 nm was studied. Using different temperature and field protocols memory phenomena were studied by the DC magnetization and magnetic relaxation measurements of the system at temperatures below T_m = 19 K. Aging experiments show an absence of any waiting time dependence in the magnetization relaxation due to a field change after zero field and field cooling. This observation discriminates the dynamics of the system from the behaviour of a classical spin-glass.
17
Content available remote

Effect of Pressure on Magnetic Properties of TM_3[Cr(CN)_6]_2 · nH_2O Nanoparticles

46%
Zentko A., Zentková M., Kavečanský V., Mihalik M., Mitróová Z., Arnold Z., Kamarád J., Cieslar M., Zeleňák V.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
489-493
EN
Effect of pressure on magnetic properties of magnetic nanoparticles, based on Prussian blue analogues, were studied in pressures up to 1.2 GPa. The Mn_3[Cr(CN)_6]_2·nH_2O and Ni_3[Cr(CN)_6]_2·nH_2O nanoparticles were prepared by reverse micelle technique. Transmission electron microscopy images show nanoparticles with average diameter of about 3.5 nm embedded in an organic matrix. The characteristic X-ray peaks of nanoparticles are more diffused and broader. Systems of nanoparticles behave as systems of interacting magnetic particles. The Curie temperature T_C is reduced from T_C = 56 K for Ni-Prussian blue analogues to T_C = 21 K for Ni-nanoparticles system and from T_C = 65 K for Mn-Prussian blue analogues to T_C = 38 K for Mn-nanoparticles system. One can explain this reduction of the Curie temperature and of the saturated magnetizationμ_s by dispersion of nanoparticles in an organic matrix i.e. by a dilution effect. Applied pressure leads to a remarkable increase in T_C for system of Mn-nanoparticles (ΔT_C/Δp = +13 K/GPa) and to only slight decrease in T_C for system of Ni-nanoparticles (ΔT_C/Δp = -3 K/GPa). The pressure effect follows behavior of the mother Prussian blue analogues under pressure. The increase in saturated magnetization, attributed to compression of the organic matrix, is very small.
18
Content available remote

^1H NMR on (Ni_xMn_{1-x})_3[Cr(CN)_6]_2 · nH_2O

46%
Bokor M., Tompa K., Kiss L., Zentková M., Zentko A., Mihalik M., Maťaš S., Mitróová Z.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
485-488
EN
We report on ^1H NMR of (Ni_xMn_{1-x})3[Cr(CN)_6]_2·15H_2O hexacyanochromates, where x changes from 0 to 1. The decay time constants of the free induction decay signals described by an effective spin-spin relaxation time T_{2eff} obtained from M(t) = M_0 exp(t/T_{2eff}) decrease as the local magnetic moments increase produced by the magnetic transition metal ions at the sites of the resonant ^1H nuclei. The recovery of the magnetization in the spin-lattice relaxation time (T_1) experiments was single-exponential.
19
Content available remote

Effect of Pressure on Magnetic Properties of (NH_3OH)_2CoF_4 Fluoro-Metal Complex

46%
Jagličić Z., Zentková M., Mihalik M., Drofenik M., Kristl M., Dojer B., Kasunič M., Golobič A., Jagodič M., Arnold Z.
|
|
issue 5
1074-1075
EN
Effect of pressure on magnetic properties of a bulk fluoro-metal complex (NH_3OH)_2MF_4 was studied. Magnetization measurements suggest that a ferromagnetic transition at T_{C1} = 47 K is followed by a ferrimagnetic one at T_{C2} = 3 K. Both transition temperatures are pressure dependent with the pressure coefficients dT_{C1}/ dp = - 2.6 K/GPa and dT_{C2}/ dp = 0.26 K/GPa. The opposite sign of the coefficients is an additional indication of a different nature (ferromagnetic/antiferromagnetic) of these two transitions. The effect of pressure on low field magnetization and exchange bias phenomena is small but still visible.
20
Content available remote

The Electronic Structure and Specific Heat of YNi_4Si

46%
Pugaczowa-Michalska M., Falkowski M., Kowalczyk A., Timko M., Reiffers M., Mihalik M., Šebek J., Šantava E.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
323-326
EN
The studies of the electronic structure and the specific heat of YNi_4Si are reported. Below the Fermi energy (E_F) the density of states contains mainly the 3d states of Ni, which hybridized with 4d states of Y and 3p states of Si. The theoretical electronic specific heat coefficient (12.32 mJ/(mol K^2)) obtained for equilibrium lattice parameters and the experimental value (13 mJ/(mol K^2)) are in a reasonable agreement.
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.