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: 9

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

Structural Phase Transition in CePd₂Ga₂ under Hydrostatic Pressure

100%
Doležal P., Klicpera M., Prchal J., Javorský P.
Acta Physica Polonica A
|
2015
|
vol. 127
|
issue 2
219-221
EN
The structural phase transition from tetragonal to triclinic structure in CePd₂Ga₂ compound was studied by means of electrical resistivity measurement under hydrostatic pressure. The shift of the transition to the higher temperature with increasing pressure was revealed: 195 K in 3 GPa compared to 125 K in ambient pressure.
2
Content available remote

Magnetic, Thermal and Transport Properties of YbPt_2Si_2 and Yb_2Pt_3Si_5 Single Crystals

100%
Fikáček J., Prchal J., Sechovský V.
|
|
vol. 126
|
issue 1
310-311
EN
Single crystals of YbPt_{2}Si_{2} and Yb_{2}Pt_{3}Si_{5} have been prepared by solvent growth method with Sn flux, characterized by X-ray diffraction and by EDX microprobe analysis and investigated by measurement of magnetization, specific heat and electrical resistivity as functions of temperature and magnetic field. YbPt_{2}Si_{2} (Yb_{2}Pt_{3}Si_{5}) crystalizes in the tetragonal CaBe_{2}Ge_{2}-type (orthorhombic U_{2}Co_{3}Si_{5}-type) structure. Both compounds exhibit metallic resistivity behavior without visible anomaly, which could be connected with onset of magnetic ordering. Neither the specific heat shows any sign of magnetic ordering down to 0.5 K. The corresponding temperature dependences of the magnetic susceptibility of both compounds behave qualitatively similar, which is reminiscent of spin fluctuation behavior: a broad maximum at high temperatures, a shallow minimum at lower temperatures, followed by an upturn with further cooling the crystal, which can be suppressed by applying a sufficient magnetic field. The rather low values of the γ-coefficients of the specific heat (~25÷35 mJ·mol·K^{-2}) do not support the mixed valence scenario discussed in literature for YbPt_{2}Si_{2}.
3
Content available remote

Magnetic Structure in UIrAl

100%
Prokeš K., Prchal J., Sechovský V., Andreev A.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
339-342
EN
By means of neutron diffraction on a hexagonal UIrAl single crystal we find that this system orders ferromagnetically at low temperatures with magnetic moments of 0.93 (10) μ_B aligned along the c axis. The Curie temperature T_C = 65 (5) K determined from the diffraction experiment is in good agreement with bulk magnetic measurements.
4
Content available remote

Isostructural Transition in RTAl Compounds at High Temperatures

100%
Prchal J., Javorský P., de Boer F., Moleman A.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
335-338
EN
Based on previously discovered forbidden values of the c/a ratio, we studied anomalies in the temperature evolution of the lattice parameters (a, c) of several hexagonal RTAl compounds at high temperatures (above room temperature). The compound ErNi_{0.45}Cu_{0.55}Al, that seemed to be impossible to be prepared in single-phase form, reaches the single-phase state at temperatures above 493 K (220°C). On the other hand, the compound TbNi_{0.7}Cu_{0.3}Al - that was expected to undergo a first-order structural phase transition at high temperatures - exhibits a second-order type transition when approaching the critical values of the c/a ratio. These results are in agreement with idea of a forbidden range of c/a values in these compounds.
5
Content available remote

Magnetism in TmCo₂

88%
Šebesta J., Prchal J., Valenta J., Kratochvílová M., Sechovský V.
Acta Physica Polonica A
|
2015
|
vol. 127
|
issue 2
379-381
EN
Recently a new wave of interest in physics of RCo₂ compounds has been boosted by reports on unusual magnetic short range order configurations in the heavy rare-earth RCo₂ ferrimagnets in paramagnetic state. The newly observed phenomenon called parimagnetism consists in a short-range antiferromagnetic coupling between small ferromagnetic Co clusters and the nearest rare-earth moments. This paper is devoted to results of our experimental investigation of carefully prepared and characterized samples of TmCo₂, a compound on which controversial results can be found in literature. Detailed magnetization, AC susceptibility, specific heat and electrical resistivity measurements revealed two magnetic phase transitions at 4.6 and 3.6 K, respectively. The anomalies connected with the transitions are strongly dependent on magnetic field and hydrostatic pressure. The AC susceptibility anomaly connected with the onset of parimagnetism has been found at T_{f}=35 K. Contrary to other heavy rare-earth RCo₂ counterparts T_{f} of TmCo₂ is entirely pressure independent.
6
Content available remote

Presence of Parimagnetism in Ho(Co_{1-x}Si_{x})_{2} Under Hydrostatic Pressure

88%
Valenta J., Prchal J., Kratochvílová M., Míšek M., Sechovský V.
|
|
vol. 126
|
issue 1
406-408
EN
A new configuration of cobalt magnetic moments with respect to rare-earth ones on local level, named as parimagnetism, surviving above the Curie temperature was determined few years ago for ErCo_{2}. Occurrence of parimagnetism has recently been confirmed also for HoCo_{2}. In this paper we present results manifesting considerable composition and hydrostatic-pressure influence on characteristic temperatures of magnetism in Ho(Co_{1-x}Si_{x})_{2} compounds and draw a preliminary scenario analyzing the exchange interactions involved.
7
Content available remote

Lattice Heat Capacity in RTAl (R = Y, Lu;T = Ni, Cu, Pd) Compounds

88%
Daniel P., Javorský P., Prchal J., Daniš S., Šantavá E.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
331-334
EN
We present analysis of the specific heat of the RTAl (R = Y, Lu;T = Cu, Ni, Pd) compounds. We focus on the lattice contribution and analyze the dependence of all the characteristic parameters in the Debye and Einstein models on the atomic masses and interatomic distances.
8
Content available remote

Pressure Influence on Magnetic Properties of TbNiAl

88%
Javorský P., Prchal J., Klicpera M., Kaštil J., Míšek M.
|
|
vol. 126
|
issue 1
280-281
EN
We have investigated the effect of hydrostatic pressure on magnetic properties of TbNiAl, crystallizing in hexagonal ZrNiAl-type structure. TbNiAl orders antiferromagnetically below T_{N}=45 K and undergoes further magnetic phase transition to another AF phase at T_{1}=23 K. The magnetic field of B_{c} ≅ 0.3 T applied along the c-axis at 2 K leads to the transition to ferromagnetic order. By applying the hydrostatic pressure, both T_{N} and T_{1} remain almost unaffected whereas B_{c} shows a strong increase. The hydrostatic pressure stabilizes the antiferromagnetic state which can be related to development of structural parameters.
9
Content available remote

Magnetism in RCo_{2} (R = Dy, Ho, Er, Tm) Under Hydrostatic Pressure

64%
Prchal J., Šebesta J., Valenta J., Míšek M., Turčinková D., Lapčák L., Prokleška J., Kratochvílová M., Sechovský V.
|
|
vol. 126
|
issue 1
288-289
EN
The short-range parimagnetic configurations, observed in the heavy rare-earth RCo_{2} compounds in paramagnetic range far above the Curie temperature T_{C}, consist in formation of ferromagnetic cobalt clusters antiferromagnetically coupled to the neighboring R magnetic moments. The characteristic temperature of the onset of parimagnetism T_{f} is very sensitive to changes of external conditions like pressure or composition. The pressure coefficients ∂T_{f}/∂p and ∂T_{C}/∂p are comparable, indicating a close connection of underlying mechanisms. Our recent measurements indicate systematic evolution of the pressure coefficients with spanning the rare-earth series from Dy through Tm in RCo_{2} with a specific case TmCo_{2}.
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.