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: 8

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  64.70.Pf
help Sort By:

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

Free Volume Study on Three Types of Shape Memory Polymers by Positron Annihilation

100%
Ujihira Y., Li H., Ito K.
|
|
vol. 95
|
issue 4
677-682
EN
Temperature dependence of nanoscopic environment of shape memory polymers such as polynorbornene (T_{g}≈313 K), polyurethane (T_{g}≈321 K=dynamic viscoelasticity, destruction of hydrogen bond ≈353 K) and styrene-butadiene copolymer (T_{m}=333 K) is observed in terms of free volume parameters - average size, numerical concentration and size distribution - estimated from positronium lifetime measurement, and mechanisms of their shape recoveries are discussed at a molecular level.
2
Publication available in full text mode
Content available

Structural Phase Transition of Co-Ni-Si-B Amorphous Alloy

63%
Jakubczyk E.
Acta Physica Polonica A
|
2001
|
vol. 99
|
issue 6
673-681
EN
Structural changes of Co_{66}Ni_{12} Si_9B_{13} amorphous alloy, stimulated by isochronal and isothermal annealing, were observed by means of the methods: electrical resistivity, Hall effect and X-ray diffraction. In the amorphous matrix at the temperature 673 K phasesα-Co and (Co,Ni)_5Si_2B are created, while at the temperature 773 K the phase (Co,Ni)_3B is formed. The structural phase transitions are related to abrupt decrease in electrical and Hall resistivities at the background of systematic decrease in these parameters values during the alloy transition from the amorphous to the crystalline state.
3
Content available remote

Replica-Symmetry Broken Solution of Simple Pseudospin Model of Orientational Glass

51%
Walasek K., Lukierska-Walasek K., Wodawski M.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
407-410
EN
The first stage of the replica-symmetry breaking for a simple quadrupolar glass model using the Parisi ansatz has been performed in a wide range of temperatures including T = 0. It has been obtained that the entropy of the system increases considerably compared to that calculated within the replica symmetric theory.
4
Publication available in full text mode
Content available

Dynamics of 4-(2-hexyloxy-ethoxy) 4'-cyanobiphenyl Molecules on Approaching a Glass Transition as Studied by Dielectric Spectroscopy

51%
Massalska-Arodź M., Witko W., Gorbachev V., Hartmann L., Kremer F.
Acta Physica Polonica A
|
2003
|
vol. 104
|
issue 6
527-536
EN
The complex dielectric permittivity of 4-(2-hexyloxy-ethyloxy) 4'-cyano-biphenyl measured in the frequency range from 0.03 Hz to 10^9 Hz is presented. Monotropic sequence of thermodynamic phases was found with two stable phases (isotropic and crystal) and three metastable states (supercooled isotropic phase, its glass and a smectic phase observed only on heating the sample first cooled rapidly to the liquid nitrogen temperature). In isotropic and supercooled isotropic phases the temperature dependence of the dielectric relaxation time was described by the same Vogel-Fulcher-Tammann formula while in a smectic phase it was of the Arrhenius type. In the transition from a supercooled isotropic phase to a smectic phase the relaxation rate of molecular motions around the short axes increases by two decades. Comparison of the relaxation behaviour and polymorphism of 4-(2-hexyloxy-ethyloxy) 4'-cyano-biphenyl of linear molecules with two chiral cyanobiphenyls is discussed.
5
Content available remote

Application of the SPin Glass Formalism to the Quadrupolar Glass Na(CN)_{x}Cl_{1-x}

51%
Walasek K.
|
EN
A new model of quadrupolar glass of mixed alkali halide-cyanide crystals is proposed. This model is treated by the Sherrington-Kirkpatrick like procedure. Physical consequences of our approach are discussed. The temperature dependence of the quadrupolar Edwards-Anderson order parameter and elastic constant C_{44} near the quadrupolar glass transition was obtained.
6
Content available remote

Cavity Fields Approach to Simple Pseudospin Model of Orientational Glass

45%
De Cesare L., Lukierska-Walasek K., Rabuffo I., Walasek K.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 2
411-414
EN
A simple infinite-range model of axial quadrupolar glass is investigated within the cavity-fields approach inside a pure state and a cluster of pure states. Working at a level of a pure state, the nonlinear susceptibility is derived. When a cluster of pure states is considered, all the known results of the one-step replica-symmetry breaking approach are easily reproduced. Besides, the nonlinear susceptibility and the stability conditions are obtained and related numerical results are presented. In this way the stability range of the replica-symmetry breaking solution, quite difficult to be derived within the replica method, is established on the purely physical ground. An interesting feature is that, at any considered stage, the nonlinear susceptibility diverges at a given temperature T_{c} where the quadrupolarization and the quadrupolar glass order parameters are nonzero and finite. This may be interpreted as a signal of a glassy phase transition not in the Landau sense.
7
Publication available in full text mode
Content available

Dielectric Properties of K_{1-x}(NH_4)_xH_2PO_4 (x= 0.095) Crystal

38%
Kaszyński J., Trybuła Z., Małuszyńska H.
Acta Physica Polonica A
|
2005
|
vol. 108
|
issue 1
103-106
EN
Temperature dependences of the dielectric permittivity were studied for the ferroelectric K_{1-x}(NH_4)_xH_2PO_4 mixed crystal. The experiments revealed presence of the beginning of the dipolar glass - embryos in the concentration of ammonium x=0.095. Observations of the dielectric relaxations show much bigger effect domain mechanism than the one related to the growth of clusters of the dipolar glass.
8
Content available remote

Glass-forming ability and thermal stability of Fe62Nb8−xZrxB30 and Fe72Zr8B20 amorphous alloys?

32%
Shapaan M., Lábár J., Varga L., Lendvai J.
Open Physics
|
2004
|
vol. 2
|
issue 1
104-119
EN
Glass-forming ability (GFA) and thermal stability of Fe62Nb8B30, Fe62Nb6Zr2B30 and Fe72Zr8B20 at % amorphous alloys were investigated by calorimetric (DSC and DTA) measurements. The crystallization kinetics was studied by DSC in the mode of continuous versus linear heating and it was found that both the glass transition temperature, Tg, and the crystallization peak temperature, Tp, display strong dependence on the heating rate. The partial replacement of Nb by Zr leads to lower Tg and Tx temperatures and causes a decrease of the supercooled liquid region. JMA analysis of isothermal transformation data measured between Tg and Tx suggests that the crystallization of the Fe62Nb8B30 and Fe62Nb6Zr2B30 amorphous alloys take place by three-dimensional growth with constant nucleation rate. Nb enhances the precipitation of the metastable Fe23B6 phase and stabilizes it up to the third crystallization stage. Zr addition increases the lattice constant of Fe23B6 and, at the same time, decreases the grain size.
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.