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. 35 Acta Physica Polonica A

Years help

  1. 1 2015

  2. 2 2014

  3. 1 2012

  4. 2 2010

  5. 4 2009

More...
Authors help

  1. 35 Szymczak R.

  2. 22 Szymczak H.

  3. 19 Baran M.

  4. 6 Aleshkevych P.

  5. 6 Babonas G.

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

Results found: 35

Number of results on page
first rewind previous Page / 2 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 2 next fast forward last
1
Content available remote

Experimental Studies of Electronic Phase Separation in High Temperature Superconductors

100%
Szymczak H., Szymczak R.
Acta Physica Polonica A
|
1994
|
vol. 85
|
issue 1
79-88
EN
Experimental research on macroscopic phase separation in La_{2}CuO_{4+δ} superconductor and photo-doped cuprates is reviewed. It is shown that the properties of the mixed-phase state strongly depend on the shape and size of the phase domains formed during the phase separation process. The interplay of magnetic and superconducting properties in the mixed-phase state is considered in details. The mechanisms driving the phase separation in La_{2}CuO_{4} and photo-doped materials are discussed in connection with presented experimental results.
2
Content available remote

Phase Transitions Induced in HoCo_{3}Ni_{2} Single Crystals

81%
Zawadzki J., Ballou R., Gorges B., Szymczak R.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 2
209-218
EN
The magnetic studies of temperature and field induced phase transitions were performed on single crystals of HoCo_{3}Ni_{2} compound. The rotational-type spin reorientation was found between T_{SR1} = 160 K and T_{SR2} = 200 K. In the vicinity of T_{SR1} two different field induced transitions were observed: the first order moment reorientation type transition in the basal plane and the spin reorientation from the easy plane to the c-axis with simultaneous increase in spontaneous magnetization. The intersublattice molecular field coefficient as well as the magnetization anisotropy of Ho sublattice were determined. The observed magnetic behaviour was analysed within the framework of the spin-reorientation model, taking into account the change of the intrinsic states of rare-earth ions caused by their huge anisotropy energy. The thermal variation of the anisotropy constants of the studied compound is also presented.
3
Content available remote

H-T Phase Diagram of Magnetic Semiconductor Thin Films - Experiment

81%
Lubecka M., Maksymowicz L. J., Szymczak R., Powroźnik W.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
433-436
EN
We used the irreversibilities between the field cooled and zero field cooled dc magnetization to determine the field and composition dependence of the spin-glass freezing temperature in CdCr_{2}Se_{4} : In (REE) and CdCr_{2-2x}In_{2x}Se_{4} (0.15 ≤ x ≤ 0.35) (SG) thin films. The H-T phase diagram of samples with REE has two instability lines: the Gabay-Toulouse-type (G-T) and the De Almeida-Thouless-type (A-T) while samples in SG state are characterized by the A-T line. The A-T line of thin films was used for calculation the normalised internal magnetic field h_{m} of infinite spin clusters with long range ordering.
4
Content available remote

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

81%
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.
5
Content available remote

Electronic and Magnetic Properties of Co_{3}V_{2}O_{8} Compound

81%
Jezierski A., Szymczak R., Szymczak H., Kaczkowski J.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 1
238-240
EN
The band structures and the magnetic properties of Co_{3}V_{2}O_{8} compound have been calculated by ab initio scalar-relativistic full potential local orbital method within the local spin density approximation. The band calculations were performed for para-, ferro-, and antiferromagnetic Co_{3}V_{2}O_{8} compounds. The main contribution to the density of states at the Fermi energy comes from minority 3d states of cobalt atoms.
6
Content available remote

Raman Scattering Study of (Sr,Ca)_{10}Cu_{17}O_{29} Single Crystals

81%
Strzeszewski J., Szymczak H., Leonyuk L., Szymczak R.
Acta Physica Polonica A
|
2000
|
vol. 98
|
issue 4
429-439
EN
Polarized Raman spectra of high temperature superconducting single crystals of A_{10}Cu_{17}O_{29} (A_{10}=Ca_{4.7}Sr_{4.1}Bi_{0.3}) were studied in various scattering configurations in the range of 40-700cm^{-1}. In very distinctive spectra there were found over 20 peaks. It was observed that the flat continuum of electronic excitations in the normal state was redistributed below the critical temperature. The frequency dependent redistribution is consistent with the value of energy gap estimated using tunnelling spectroscopy techniques.
7
Content available remote

Giant Magnetocaloric Effect in Manganites

71%
Szymczak R., Kolano R., Kolano-Burian A., Dyakonov V., Szymczak H.
|
|
issue 1
203-206
EN
In this review we briefly discuss the magnetocaloric properties of the manganites. It is evidenced that the maximum entropy change observed in manganites exceeds that of gadolinium (the prototype material for room temperature refrigerators). For the manganites characterized by second-order magnetic phase transitions the scaling hypothesis is discussed. It is shown that simple phenomenological model with only one fitting parameter, presented in this paper, satisfactorily describes experimental observations.
8
Content available remote

Magnetocaloric Effect in La_{0.8}Sr_{0.2}MnO_{3} Film

71%
Szymczak R., Dyakonov K., Radelytskyi I., Dyakonov V., Szymczak H.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 1
56-58
EN
Thin epitaxial film of La_{0.8}Sr_{0.2}MnO_{3} has been deposited on yz-cut LiNbO_{3} by pulsed laser ablation. The film was characterized by X-ray diffraction and magnetic measurements as a single phase. The magnetic properties and the magnetocaloric effect have been measured as a function of magnetic field and temperature. A reasonably high magnetocaloric effect indicates that this film might provide an efficient material for micro magnetic refrigerators.
9
Content available remote

Magnetoresistance and Electroluminescence near the Curie-Weiss Temperature in the Zn_{1-x}Mn_{x}Te Light Emitting Devices

71%
Van Khoi L., Avdonin A., Szymczak R., Gałązka R., Potemski M.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 5
941-943
EN
The light emitting devices based on the p-Zn_{1-x}Mn_{x}Te bicrystals have been fabricated. The Zn_{1-x}Mn_{x}Te devices produce red and green emission originating from the internal d-shell transitions in the Mn^{2+} ions and the donor-acceptor pairs recombination, respectively. A critical behavior of the magnetic field dependence of the green emission intensity and a positive magnetoresistance near the Curie-Weiss temperature in the Zn_{1-x}Mn_{x}Te devices was observed.
10
Content available remote

Magnetic Phase Transitions in Intermetallic GdNi_{5-x}Sn_{1+x} and TbNi_{5-x}Sn_{1+x} Compounds

71%
Baran M., Szymczak H., Szymczak R., Romaka L., Skolozdra R.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
295-299
EN
Magnetization measurements were performed for intermetallic compounds GdNi_{5-x}Sn_{1+x} and TbNi_{5-x}Sn_{1+x} in the temperature range from 4.5 K to 280 K and in magnetic field up to 50 kOe. Complex magnetic phase diagram was revealed for both compounds. The results are discussed assuming three-sublattice magnetic structure and partial disordering of the structure.
11
Publication available in full text mode
Content available

Ferromagnetic Resonance Studies of La_{0.67}Ca_{0.33}MnO_3 Film under Stress

71%
Kundys B., Dyakonov V., Baran M., Gierłowski P., Szymczak R.
|
EN
Ferromagnetic resonance spectra of the La_{0.67}Ca_{0.33}MnO_3 ferromagnetic film deposited onto the x-cut LiNbO_3 substrate were investigated in a wide temperature range. The strain was mechanically introduced into the film using a special holder configuration. This leads to a shift of resonance field with respect to that of the as-grown sample. Analysis of the magnetic resonance shift, induced by a mechanical stress, allowed us to determine the magnetostriction constant λ_{100}. The magnetostriction determined in this way versus saturation magnetization could be well described by the Callen and Callen theory suggesting the domination of the single ion crystal field interaction in the sample being in the ferromagnetic state.
12
Publication available in full text mode
Content available

Magnetic and Transport Properties of R_3Cu_3Sb_4 Compounds (R = La, Ce, Pr, Nd, and Sm)

62%
Skolozdra R., Baran M., Horyn A., Szewczyk A., Gorelenko Y., Szymczak H., Szymczak R.
Acta Physica Polonica A
|
2002
|
vol. 102
|
issue 3
429-435
EN
Magnetic susceptibility, electrical resistivity, and thermopower of the series of the R_3Cu_3Sb_4 compounds (R=La-Sm) were measured over the temperature ranges 1.9-300 K (susceptibility and resistivity) and 80-370 K (thermopower). Below 25 K, resistivity of these compounds grows exponentially with decreasing temperature. For some compounds, R = Ce, Sm, a maximum on temperature dependence of resistivity is observed. Ce_3Cu_3Sb_4 compound undergoes a magnetic transition at 12 K.
13
Publication available in full text mode
Content available

Physical Properties of (M_2Cu_2O_3)_m(CuO_2)_n (M = Ca, Sr, Bi) Single Crystals with Bi-2212 Phase on their Surface

62%
Babonas G., Leonyuk L., Maltsev V., Szymczak R., Reza A., Baran M., Dapkus L.
Acta Physica Polonica A
|
2001
|
vol. 100
|
issue 4
553-563
EN
The structural, optical, and magnetic properties are studied in the (M_2Cu_2O_3)_m(CuO_2)_n-type single crystals with the surface on which the Bi-2212-type phase was indicated. The physical properties of such samples were interpreted to some extent by the contributions of two phases. When the secondary phases on the surface of the samples were removed by mechanical polishing or etching by Ar^{+}-ion plasma, the physical properties were typical of the (M_2Cu_2O_3)_m(CuO_2)_n-type crystals. The optical method was shown to be effective for indication of secondary Bi-rich phases on the surface of (M_2Cu_2O_3)_m(CuO_2)_n samples.
14
Publication available in full text mode
Content available

Ellipsometric Studies of NdMnO_3 Single Crystals

62%
Babonas G., Reza A., Szymczak R., Baran M., Shiryaev S., Fink-Finowicki J., Szymczak H.
Acta Physica Polonica A
|
2004
|
vol. 105
|
issue 1-2
197-208
EN
Ellipsometric studies of NdMnO_3 single crystals of orthorhombic symmetry were carried out in the spectral range 0.5-5.0 eV. Experimental data, which were obtained on the (001)_{pc}-type planes of pseudo-cubic system, were analyzed in the model of biaxial crystal. For the first time, three componentsε_x,ε_y,ε_z of the effective dielectric function for manganites of orthorhombic symmetry were determined. From ellipsometric data, the spectra of optical conductivity and loss function were also calculated and considered. The fine structure of the spectra and optical anisotropy was the basis for discussion of the microscopic origin of the optical transitions responsible for the optical features. The electronic excitations due to dipole-forbidden spin-allowed transitions of the d-d-type in Mn-ions, f-f-type in Nd-ions and charge-transfer 2p(O)-3d(Mn) transitions were taken into account. The data for NdMnO_3 were compared with those obtained for other related undoped and doped single crystals of perovskite-type structure, LaMnO_3, (LaBa)(MnCo)O_3 and (LaCa)CoO_3.
15
Publication available in full text mode
Content available

Optical Response of La_{1-x}MnO_3/Al_2O_3 Films

62%
Babonas G., Reza A., Szymczak R., Baran M., Fröhlich K., Jasutis V., Diduszko R.
Acta Physica Polonica A
|
2003
|
vol. 103
|
issue 1
77-83
EN
La_{1-x}MnO_3 films grown by metal organic chemical vapor deposition technique on r-plane cut Al_2O_3 substrates were investigated. The change of the optical response over the La_{1-x}MnO_3/Al_2O_3 sample surface was investigated along with the temperature dependence of magnetization. The mostly pronounced difference in the spectra of dielectric function occurred in the region of the d-d transitions of Mn-ions. The changes in the optical spectra and magnetic properties were correlated to the structural features of thin film.
16
Publication available in full text mode
Content available

Magnetic Phase Transitions in Pure and Cobalt-Doped Geometrically Frustrated Ni_3V_2O_8 Single Crystals

62%
Szymczak H., Baran M., Szymczak R., Barilo S., Bychkov G., Shiryaev S.
Acta Physica Polonica A
|
2007
|
vol. 111
|
issue 1
71-77
EN
The results of magnetic measurements performed on geometrically frustrated Ni_3V_2O_8 and Ni_{3(1-x)}Co_{3x}V_2O_8 single crystals with x=0.03 are presented. It was found that Co doping did not change considerably the magnetic H-T phase diagram. Although no spin-glass effects were observed, nevertheless, a strong effect of 3 at% cobalt doping was evidenced. The main effect of Co-doping concerns the direction of the antiferromagnetic vector, which for Ni_3V_2O_8 appears along the $a$ axis, while for only slightly Co doped crystals - along the $c$ axis. This switching of direction results from distinct changes of the magnetocrystalline anisotropy due to the presence of Co^{2+} ions strongly coupled to the kagome lattice. The disorder introduced by doping has practically no effect on the magnitude of the isotropic exchange interactions. At the same time the doping suppresses the Dzyaloshinskii-Moriya exchange interactions due to the change of direction of the antiferromagnetic vector.
17
Content available remote

Spin-Glass Transition in the RCoGaO_{4} (R=Lu, Yb) Layered Cobaltites

62%
Radelytskyi I., Szymczak R., Dabkowska H., Noad H., Aleshkevych P., Szymczak H.
|
|
vol. 126
|
issue 1
230-231
EN
The frequency, temperature, and the dc and ac dependences of the magnetic susceptibility of the YbCoGaO_{4} and LuCoGaO_{4} single crystals are investigated. The YbCoGaO_{4} behaves like an Ising spin glass with a strong uniaxial anisotropy. In contrast LuCoGaO_{4} is Heisenberg-like spin glass. Dynamical scaling reveals a three dimensional phase transition near Tg and yields critical exponent values between those of Heisenberg- andIsing-like systems.
18
Content available remote

Field-Induced Magnetic Order in Frustrated TbBaCo_4O_7 Single Crystals

62%
Szymczak R., Bludov A., Gnatchenko S., Barilo S., Jezierski A., Szymczak H.
|
|
issue 2
299-302
EN
We present results of dc magnetic susceptibility measurements in TbBaCo_4O_7 single crystals performed at temperatures in the range 2-300 K and in magnetic fields up to 55 kOe. The results obtained seem to suggest that the ground state of TbBaCo_4O_7 is composed of coexisting long-range ordered and short-range ordered clusters and is transformed into a magnetically ordered weak ferromagnetic phase by application high magnetic field along c-axis.
19
Content available remote

Effect of Chemical Disorder on Geometrically Frustrated Kagome Lattice

62%
Szymczak H., Szymczak R., Baran M., Fink-Finowicki J., Krzymanska B., Aleshkevych P., Jezierski A.
Acta Physica Polonica A
|
2008
|
vol. 114
|
issue 1
35-42
EN
This paper reviews recent progress in the studies of magnetic dilutions on magnetic properties of two frustrated systems: magnetoplumbite-like SrGa_{12-x}Cr_xO_{19} and kagome staircase Co_3V_2O_8 doped with Mg ions. In the first group of compounds magnetic properties are determined by magnetic defects arising due to doping. In the case of kagome staircase compounds magnetic dilution suppresses effects of crystal field acting on magnetic ions. In particular, the dilution decreases magnetocrystalline anisotropy and anisotropy of magnetization.
20
Content available remote

Magnetic Properties of Spin-Ladders (A_{2}Cu_{2}O_{3})_{m} (CuO_{2})_{n}

62%
Baran M., Szymczak H., Szymczak R., Dyeyev S., Leonyuk L., Babonas G.
Acta Physica Polonica A
|
2000
|
vol. 97
|
issue 3
571-574
EN
Magnetization M(T) and M(H) data of single crystals of the S=1/2 quasi-one-dimensional system (A_{2}Cu_{2}O_{3})_{m}(CuO_{2})_{n} with various A-site constituents are compared. The studied orthorhombic, incommensurate crystals are characterized by m/n=5/7,7/10, and 9/13. The role of rare-earth ions located in A-sites is discussed.
first rewind previous Page / 2 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.