Search results

1

On the Possible Origin of Large Value of Magnetic Anisotropy Constant in PbSnMnTe Mixed Crystals

100%

Łusakowski A., Story T., Gałązka R.

Acta Physica Polonica A

|

1993

|

vol. 84

|

issue 4

829-831

EN

In PbSnMnTe crystals with the concentration of conducting holes of the order of 10^{21} cm^{-3}, the magnetic anisotropy constant K measured in ferromagnetic resonance experiments is nearly one order of magnitude larger than expected. In the present paper we investigate a contribution ΔK to the anisotropy constant, origin of which is the s-d interaction and the spin-orbit coupling.

2

Single-Crystal Growth of f-Electron Intermetallics in a Tetra-Arc Czochralski Furnace

63%

Szlawska M., Kaczorowski D.

Acta Physica Polonica A

|

2013

|

vol. 124

|

issue 2

336-339

EN

The Czochralski technique has induced technological revolution in the electronic industry. It has also been widely used in the fundamental research area, as it allows obtaining high-quality single crystals of large variety of binary, ternary and multinary compounds. The unique tetra-arc Czochralski furnace installed at the Institute of Low Temperature and Structure Research, Polish Academy of Sciences in Wrocław, described in detail in the article, has been used to prepare a large number of single crystals of various Ce- and U-based intermetallic phases. Their excellent quality has facilitated advanced investigations of their anisotropic, often highly unusual physical properties.

3

Thickness Dependent Magnetic Properties of Polycrystalline Nickel Thin Films

63%

Parlak U., Aköz M., Tokdemir Öztürk S., Erkovan M.

Acta Physica Polonica A

|

2015

|

vol. 127

|

issue 4

995-997

EN

Magnetization directions of ferromagnetic ultra-thin films can be altered by increasing the thickness. The transition between in-plane and out-of-plane axes is induced by the competition among the magnetostatic, magnetocrystalline and magnetoelastic anisotropy energies. Such an effect has attracted more interest recently, due to the applications in magneto-optical recording technologies. In this study, we have investigated by magneto-optical Kerr effect the magnetization properties of magnetron sputtered nickel thin films.

4

Phase Transitions in ErFe_{1-x}Al_{x}O_{3} System (x ≤ 0.1)

63%

Bombik A., Pacyna A., Witek W.

Acta Physica Polonica A

|

1994

|

vol. 85

|

issue 2

263-266

EN

The magnetic measurements for some representatives of ErFe_{1-x}Al_{x}O_{3} system were performed. The obtained results indicate an essential influence of nonmagnetic substitution on physical behaviour of examined compounds.

5

Spin Reorientation and Exchange Coupling in the Dy_{1-x}Er_{x}Fe_{10}Si_{2} Compounds

63%

Stefański P., Kowalczyk A., Skoryna D., Szlaferek A., Wrzeciono A.

Acta Physica Polonica A

|

1994

|

vol. 85

|

issue 2

259-262

EN

The structural and magnetic properties of Dy_{1_{x}}Er_{x}Fe_{10}Si_{2} are investigated. X-ray analysis reveals that these compounds are of the tetragonal ThMn_{12} structure. In this structure the rare earth atoms occupy one crystallographic position 2(a). The unit cell contains 26 atoms. The spin reorientation temperature, T_{SR}, was measured from the temperature dependence of the initial susceptibility using an ac bridge of mutual inductance of the Harsthorn type. Dy^{+3} and Er^{+3} have opposite contributions to the entire magnetic anisotropy. The spin reorientation temperature is found to be about 271 K in DyFe_{10}Si_{2} and 48 K in ErFe_{10}Si_{2}. The values are discussed applying the crystal field model. The value of the rare earth-transition metal exchange coupling constant J_{RFe}/k_{B} derived from the mean-field model analysis of the Curie temperature is about -13 K. The Fe-Fe exchange integral is much higher and is equal to about 75 K.

6

Structural and Magnetic Characterization of NiMnSb Half-Heusler Alloy Prepared by Rapid Quenching

63%

Ryba T., Vargova Z., Varga R., Ilkovic S., Reiffers M., Haskova V., Szabo P., Kravcak J., Gyepes R.

|

vol. 126

|

issue 1

206-207

EN

NiMnSb half-Heusler alloy in the form of a rod has been prepared by rapid quenching (suction-casting) method. The rod is characterized by single phase C1_b crystalline structure with lattice parameter a=5.982 Å. Magnetic measurements reveal an isotropic character of bulk NiMnSb alloy. Our study shows relatively high spin polarization of bulk NiMnSb in the range 35-50%.

7

Magnetic Anisotropy and Exchange Interactions in R_{n+1}Co_{3n+5}B_{2}n Compounds

63%

Kowalczyk A.

Acta Physica Polonica A

|

1994

|

vol. 85

|

issue 3

623-626

EN

The individual Co site contributions to the magnetocrystalline anisotropy in RCo_{5}, RCo_{4}B and R_{3}Co_{11}B_{4} compounds have been studied. An analysis is given of the room temperature anisotropy constants of these compounds by using a model of Streever. The values of the rare earth-transition metal exchange coupling J_{RCo}/k_{B} derived by mean field analysis of the Curie temperatures are -11.2 K, -15 K and -20.9 K, respectively. In general, a decrease in J_{RCo}/k_{B} with increasing Co concentration is observed.

8

Single-Ion Rare Earth Anisotropy in ThMn_{12}-Type Compounds

63%

Stefański P.

Acta Physica Polonica A

|

1994

|

vol. 85

|

issue 3

615-621

EN

The single-ion rare earth anisotropy was investigated in ThMn_{12}-type compounds. For this purpose the crystal electric field parameter values were studied. In these compounds, described by formula RFe_{12-x}T_{x}, R = rare earth, T = Ti, V, Cr, Mo, W and Si, the T atoms have strong crystallographic site preference changing the local crystal electric field potential which "sees" the rare earth ion. The crystal electric field potentials A^{0}_{2} were calculated considering this site preference. The summations were performed taking into account the nearest neighborhood of the rare earth ion according to the recent results of band structure calculations. The charges of the surrounding Fe and T atoms were established applying the chemical bond model proposed by Pauling. The absolute value of A^{0}_{2} decreases when the content of vanadium increases in 8(i) position, which is in agreement with experimental data. Localization of Si atoms in 8(j) and 8(f) causes a decrease in A^{0}_{2}. The ^{155}Gd Mössbauer spectroscopy data confirm this fact. Miedema's "macroscopic" atom model of cohesion in alloys was applied for interpretation of the role of T atoms in the isomer shift and volume effects.

9

Magnetic Characterization of Co_2MnSi Heusler Microwires

63%

Ryba T., Vargova Z., Varga R., Kováč J., Zhukova V., Zhukov A.

|

vol. 126

|

issue 1

196-197

EN

We report on the basic magnetic properties of glass-coated Co_2MnSi Heusler microwires. Measurements of hysteresis loops in different directions show that easy magnetization axis coincides with the wire's axis. The frequency dependence of the coercive field has been measured at room temperature in the frequency range from 10 Hz to 10 kHz. The coercivity decreases with the frequency up to 100 Hz and then increases linearly up to 1 kHz.

10

Anomalous Reversible Torque in Layered Superconducting Bi_{2}Sr_{2}CaCu_{2}O_{x} Single Crystal

63%

Drzazga Z., Borgieł W., Szymczak R., Szymczak H.

Acta Physica Polonica A

|

1996

|

vol. 89

|

issue 1

91-98

EN

Magnetic anisotropy of layered superconducting Bi_{2}Sr_{2}CaCu_{2}O_{x} single crystal was investigated by the torque method in the reversible regime. The torque was analyzed in the model taking into account 2D layered structure. Considered model gives the better fit to the data when the magnetic field is applied near (a, b) plane. Obtained results establish to 6×10_{3} value of the superconducting effective mass anisotropy coefficient ε.

11

Ground State Properties of Tb^{3+} Ion in TbNi_{10}Si_{2}

63%

Stefański P., Suski W., Wochowski K., Mydlarz T.

Acta Physica Polonica A

|

1997

|

vol. 92

|

issue 2

281-284

EN

Ground state properties of Tb^{3+} ion were investigated in the tetragonal ThΜn_{12}-type TbNi_{10}Si_{2} compound on the basis of temperature dependence of the paramagnetic susceptibility and magnetization measurements. The rare earth temperature dependence of the susceptibility was calculated using the Van Vleck equation. The Γ_{t5}^{(1)} doublet is suggested to be a ground state separated by 9 K from the first excited singlet Γ_{t1}^{(2)}. The magnetic moment associated with the ground state doublet agrees with saturation magnetization data at 4.2 K. The overall crystal field splitting is estimated to be 105 K.

12

Role of Boron in Nd(Co_{1-x}B_{x})_{5} System

63%

Kowalczyk A., Smardz L.

Acta Physica Polonica A

|

1997

|

vol. 92

|

issue 2

285-289

EN

The influence of boron atoms on the magnetic properties of Νd(Co_{1-x}B_{x})_{5} (i.e. ΝdCo_{5}, NdCo_{4}B, Νd_{3}Co_{11}Β_{4} and Νd_{2}Co_{7}Β_{3}) compounds has been studied. These structures are based on the well-known CaCu_{5} structure. They all have the hexagonal symmetry and belong to the space group of P6/mmm. The experimental values of the Curie temperatures (T_{c}) of Nd(Co_{1-x}B_{x})_{5} are used to calculate the effective intersublattice exchange interactions (J_{NdCO}) between Nd and Co sublattices. As the Β content increases, a tendency to decrease in J_{NdCO} and T_{c} is found. This variation is compared with that observed for the Co magnetic moment.

13

Origin of Magnetic Anisotropy of Gd_{5}Si_{2}Ge_{2} Compound

63%

Szymczak R., Kolano R., Kolano-Burian A., Hawelek L., Krzymanska B., Aleshkevich P., Dyakonov V., Szymczak H.

Acta Physica Polonica A

|

2012

|

vol. 121

|

issue 5-6

1261-1262

EN

The second-order anisotropy constant K_2 in polycrystalline Gd_5Si_2Ge_2 giant magnetocaloric material was measured as a function of temperature by the modified singular point detection technique. Although the structural, electrical, thermal, magnetic and magnetocaloric properties of the Gd_5Si_2Ge_2 have been rather well investigated experimentally, magnetic anisotropy of this system is almost unknown. The singularity indicating the anisotropy field was determined analyzing ac susceptibility data taking into account several features of the magnetization curve. The temperature dependence of the anisotropy fields was measured from 4.2 K up to the Curie temperature. The observed relationship between K_2 (T)/K_2 (0) and magnetization M (T)/M (0) was explained assuming dipolar origin of magnetic anisotropy of Gd_5Si_2Ge_2 compound.

14

Magnetic and Structural Characterization of Nickel and Iron Based Heusler Ribbons Ni₂FeZ (Z = In, Sn, Sb)

63%

Frol'ová L., Ryba T., Vargová Z., Komanický V., Kováč J., Gyepes R., Varga R.

Acta Physica Polonica A

|

2017

|

vol. 131

|

issue 4

735-737

EN

Comparison of structural, chemical, and magnetic properties of Ni₂FeZ (Z = In, Sn, Sb) Heusler ribbons produced by melt-spinning method is presented. The aim of work was to prepare the Heusler alloys with the appropriate chemical composition in a single step without additional thermal treatment. Scanning electron microscopy analysis revealed polycrystalline structure of all samples. It is shown that correct L2₁ structure of Ni₂FeSb can be obtained in a single production step. On the other hand, no Heusler L2₁ phase (nor its variants) occur in Ni₂FeSn alloy. Additionally, magnetic characterization revealed high Curie temperatures of the Heusler phases (above 600 K for Ni₂FeSb and 800 K for Ni₂FeIn).

15

Neutron and EPR Study of Cu(tn)Cl_{2} - a~Two-Dimensional Spatially Anisotropic Triangular-Lattice Antiferromagnet

63%

Tarasenko R., Orendáčová A., Čižmár E., Maťaš S., Orendáč M., Zeleňák V., Pavlík V., Siemensmeyer K., Zvyagin S., Wosnitza J., Feher A.

|

vol. 126

|

issue 1

232-233

EN

We have studied the temperature dependence of the lattice parameters and the influence of spin anisotropy on the electron paramagnetic spectra of Cu(tn)Cl_2, an S=1/2 quasi-two-dimensional spatially-anisotropic triangular-lattice Heisenberg antiferromagnet. The variation of the resonance fields with temperature reflects the presence of an easy-plane exchange anisotropy with J_{z}/J_{x,y}<1 and g-factor anisotropy, g_{z}/g_{x,y}>1.

16

Dependence of Exchange Bias Field on Thickness of Antiferromagnetic Layer in NiFe/IrMn Structures

63%

Dzhun I., Chechenin N., Chichay K., Rodionova V.

Acta Physica Polonica A

|

2015

|

vol. 127

|

issue 2

555-557

EN

Magnetic properties of ferromagnetic/antiferromagnetic thin-films structures for spin-valve applications have been studied. Multilayer structures of Ta/Co/IrMn/Ta and Ta/FeNi/IrMn/Ta were deposited on Si substrate at room temperature by DC magnetron sputtering. Thickness of the antiferromagnetic layer changed from 10 to 50 nm. The coercive force was found to be non-monotonic function of the antiferromagnetic layer thickness. The exchange bias for 30-50 nm antiferromagnetic layers (73 Oe) is about 10 Oe larger than for 10-20 nm antiferromagnetic layers. Moreover, it was demonstrated that the alternative sequence of the deposition (antiferromagnetic layer on the top or below the ferromagnetic layer) leads to dramatic changes of structures magnetic properties.

17

Magnetic Properties of Magnetoplasmonic Crystals Based on Commercial Digital Discs

63%

Belyaev V., Grunin A., Chichay K., Shevyrtalov S., Fedyanin A., Rodionova V.

Acta Physica Polonica A

|

2015

|

vol. 127

|

issue 2

546-548

EN

Several topics of photonics are targeted at the enhancement of magneto-optical response in the nanostructures. One of the approaches is creating of the magnetoplasmonic crystals based on the substrates made of the digital discs (CD, DVD, BD) with ferromagnetic film. It is necessary to investigate in-plane anisotropy of magnetoplasmonic crystals and influence of the ferromagnetic layer thickness on increase of the mean free path of edge magnetoplasmons. Ni-based magnetoplasmonic crystals were investigated using the vibrating sample magnetometer by LakeShore. All samples had anisotropic in-plane magnetic properties because of the induced anisotropy caused by the stripe-like periodic structure of the substrates. A step-like behaviour of the hysteresis loops in case of the transverse plasmon propagation way was observed for Ni-based magnetoplasmonic crystals. Measurements along the plasmon propagation way showed near-rectangular hysteresis loops typical for the Ni-based thin films for certain samples. Step-like behaviour of the hysteresis loops for the Ni-based magnetoplasmonic crystals can be explained as a result of interaction between Ni films that covered the top and the lateral sides of the substrate stripes.

18

Magnetic Anisotropy in GeMnTe - ab initio Calculations

63%

Łusakowski A., Bogusławski P.

|

vol. 126

|

issue 5

1177-1179

EN

Density functional theory calculations of the energy of magnetic anisotropy in GeMnTe were performed using OpenMX package with fully relativistic pseudopotentials. The discussion of microscopic origin of magnetic anisotropy was conducted. The main conclusion is that the magnetic anisotropy is caused by interplaty between spin-orbit and Coulomb interactions. The discussion includes also the influence of the free carriers concentration on the amplitude of energy of magnetic anisotropy. The important role of the chemical disorder is also pointed out.

19

The Influence of the Temperature, External Magnetic Field, and the Thickness of Pt Sublayer on the Magnetocrystalline Anisotropy Constants in Co/Pt Multilayers

63%

Louail L., Azizi A., Moula B., Maouche D.

Acta Physica Polonica A

|

2000

|

vol. 98

|

issue 6

705-713

EN

In this paper we present the behaviour of the magnetocrystalline anisotropy constants of [Co_{32Å}Pt_{xÅ}]_{6} multilayers as a function of temperature, external magnetic field, and non-magnetic layer thickness, observed by means of a torque magnetometer in an in-plane configuration. We have determined the magnetocrystalline anisotropy constants from the magnetic torque curves for different temperatures and in different magnetic fields, taking into account the angle difference between the directions of the external field and the magnetization. Among the results of this paper there are the determination of the critical thickness of Pt and the need to introduce the third order anisotropy constant in the analysis.

20

Magnetic Anisotropy of Lu_2Co_{17-x}Si_x Single Crystals

63%

Tereshina E., Andreev A., Šantavá E., Daniš S.

|

EN

Magnetic anisotropy of Lu_2Co_{17-x}Si_x single crystals grown by the Czochralski method was investigated. The homogeneity range of Si substitution for Co extends up to x = 3.4 in Lu_2Co_{17-x}Si_x solid solutions. The unit cell volume, Curie temperature, and spontaneous magnetic moment decrease monotonously with increasing Si content. Lu_2Co_{17} has the easy-plane type of magnetic anisotropy in the ground state, which changes into the easy-axis type by two spin-reorientation transitions of the second-order, the easy-plane-easy-cone at T_{SR1}~680 K and the easy-cone - easy-axis at T_{SR2}~730 K. Upon Si substitution, the observed spin-reorientations shift towards the lower temperatures for Lu_2Co_{17-x}Si_x (T_{SR1}~75 K and T_{SR2}~130 K in Lu_2Co_{16}Si) and vanish for compounds with 1

Refine search results

On the Possible Origin of Large Value of Magnetic Anisotropy Constant in PbSnMnTe Mixed Crystals

Single-Crystal Growth of f-Electron Intermetallics in a Tetra-Arc Czochralski Furnace

Thickness Dependent Magnetic Properties of Polycrystalline Nickel Thin Films

Phase Transitions in ErFe_{1-x}Al_{x}O_{3} System (x ≤ 0.1)

Spin Reorientation and Exchange Coupling in the Dy_{1-x}Er_{x}Fe_{10}Si_{2} Compounds

Structural and Magnetic Characterization of NiMnSb Half-Heusler Alloy Prepared by Rapid Quenching

Magnetic Anisotropy and Exchange Interactions in R_{n+1}Co_{3n+5}B_{2}n Compounds

Single-Ion Rare Earth Anisotropy in ThMn_{12}-Type Compounds

Magnetic Characterization of Co_2MnSi Heusler Microwires

Anomalous Reversible Torque in Layered Superconducting Bi_{2}Sr_{2}CaCu_{2}O_{x} Single Crystal

Ground State Properties of Tb^{3+} Ion in TbNi_{10}Si_{2}

Role of Boron in Nd(Co_{1-x}B_{x})_{5} System

Origin of Magnetic Anisotropy of Gd_{5}Si_{2}Ge_{2} Compound

Magnetic and Structural Characterization of Nickel and Iron Based Heusler Ribbons Ni₂FeZ (Z = In, Sn, Sb)

Neutron and EPR Study of Cu(tn)Cl_{2} - a~Two-Dimensional Spatially Anisotropic Triangular-Lattice Antiferromagnet

Dependence of Exchange Bias Field on Thickness of Antiferromagnetic Layer in NiFe/IrMn Structures

Magnetic Properties of Magnetoplasmonic Crystals Based on Commercial Digital Discs

Magnetic Anisotropy in GeMnTe - ab initio Calculations

The Influence of the Temperature, External Magnetic Field, and the Thickness of Pt Sublayer on the Magnetocrystalline Anisotropy Constants in Co/Pt Multilayers

Magnetic Anisotropy of Lu_2Co_{17-x}Si_x Single Crystals