Positron annihilation response and broadband dielectric spectroscopy: Propylene carbonate

被引:19
作者
Bartos, J. [1 ]
Majernik, V. [2 ]
Iskrova, M. [2 ]
Sausa, O. [2 ]
Kristiak, J. [2 ]
Lunkenheimer, P. [3 ]
Loidl, A. [3 ]
机构
[1] SAS, Inst Polymer, SK-84236 Bratislava, Slovakia
[2] SAS, Inst Phys, SK-84228 Bratislava, Slovakia
[3] Univ Augsburg, Ctr Elect Correlat & Magnetism, D-86135 Augsburg, Germany
关键词
Dielectric properties; relaxation; electric modulus; Glass transition; Liquid crystals and molecular liquids; Positron annihilation; LIQUID-GLASS TRANSITION; FREE-VOLUME; 2-ORDER-PARAMETER DESCRIPTION; LIFETIME; TEMPERATURE; RELAXATION; DEPENDENCE; MODEL; ANOMALIES; FORMERS;
D O I
10.1016/j.jnoncrysol.2009.03.014
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
A phenomenological analysis of the ortho-positronium (o-Ps) lifetimes from positron annihilation lifetime spectroscopy (PALS) and the dielectric alpha-relaxation times from broadband dielectric spectroscopy (BDS) on glass-forming propylene carbonate (PC) is presented. As known from other glass-formers, the temperature dependence of the o-Ps lifetime, iota(3), shows a sigmoidal increase with increasing temperature, which can be ascribed to an increase of free volume. The onset of the high-temperature plateau in the iota(3) - T plot at T-b2(L) similar to 200 K occurs when iota(3) matches the mean relaxation time of the primary alpha-process. In addition, it coincides with the crossovers in the dielectric parameters, i.e., relaxation strength and spectral width, of the main process and is approximately related to a crossover of the alpha-relaxation time iota(alpha)(T) from non-Arrhenius to Arrhenius behavior. We demonstrate that in PC the changes of slope seen in iota(3) can be traced back to corresponding anomalies in the temperature-dependent loss due to transitions between distinct spectral regions as the relaxation and the excess wing. Overall, all the empirical coincidences indicate a close connection between the PALS response and the dielectric relaxation for PC. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码:794 / 799
页数:6
相关论文
共 48 条
[1]   FAR IR-SPECTRA AND HEAT-CAPACITIES FOR PROPYLENE CARBONATE AND PROPYLENE-GLYCOL, AND THE CONNECTION TO THE DIELECTRIC RESPONSE FUNCTION [J].
ANGELL, CA ;
BOEHM, L ;
OGUNI, M ;
SMITH, DL .
JOURNAL OF MOLECULAR LIQUIDS, 1993, 56 :275-286
[2]   VISCOUS BEHAVIOUR OF SUPERCOOLED LIQUIDS [J].
BARLOW, AJ ;
LAMB, J ;
MATHESON, AJ .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1966, 292 (1430) :322-&
[3]   Positron annihilation lifetime response and relaxation dynamics in glycerol [J].
Bartos, J ;
Sausa, O ;
Racko, D ;
Kristiak, J ;
Fontanella, JJ .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 2005, 351 (33-36) :2599-2604
[4]   Free volume factor in supercooled liquid dynamics [J].
Bartos, J ;
Sausa, O ;
Bandzuch, P ;
Zrubcová, J ;
Kristiak, J .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 2002, 307 :417-425
[5]  
Bartos J, 2007, ARW NATO SERIES SOFT, P113
[6]  
BARTOS J, 2000, ENCY ANAL CHEM, P7968
[7]   Beta relaxation versus high frequency wing in the dielectric spectra of a binary molecular glass former -: art. no. 225701 [J].
Blochowicz, T ;
Rössler, EA .
PHYSICAL REVIEW LETTERS, 2004, 92 (22) :225701-1
[8]  
BOHMER R, 1989, J APPL PHYS, V65, P901, DOI 10.1063/1.342990
[9]   NONEXPONENTIAL RELAXATIONS IN STRONG AND FRAGILE GLASS FORMERS [J].
BOHMER, R ;
NGAI, KL ;
ANGELL, CA ;
PLAZEK, DJ .
JOURNAL OF CHEMICAL PHYSICS, 1993, 99 (05) :4201-4209
[10]   POSITRON LIFETIME SPECTRA IN MOLECULAR SUBSTANCES [J].
BRANDT, W ;
SPIRN, I .
PHYSICAL REVIEW, 1966, 142 (01) :231-&