Electrical conductivity and dielectric relaxation in non-crystalline films of tungsten trioxide

被引:40
作者
Hutchins, M. G.
Abu-Alkhair, O.
El-Nahass, M. M. [1 ]
Abdel-Hady, K.
机构
[1] Oxford Brookes Univ, Sch Engn, Oxford OX3 0BP, England
[2] King Abdulaziz Univ, Fac Sci, Dept Phys, Jeddah, Saudi Arabia
[3] Ain Shams Univ, Fac Educ, Dept Phys, Cairo 11757, Egypt
[4] Menia Univ, Fac Sci, Dept Phys, Al Minya, Egypt
关键词
conductivity; dielectric properties; relaxation; electric modulus;
D O I
10.1016/j.jnoncrysol.2007.06.042
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
Amorphous tungsten trioxide (a-WO3) thin films were prepared by thermal evaporation technique. The electrical conductivity and dielectric properties of the prepared films have been investigated in the frequency range from 100 Hz to 100 kHz and in the temperature range 293-393 K. In spite of the absence of the dielectric loss peaks, application of the dielectric modulus formulism gives a simple method for evaluating the activation energy of the dielectric relaxation. The frequency dependence of sigma(omega) follows the Jonscher's universal dynamic law with the relation sigma(omega) = sigma(dc) + A omega(s), where s is the frequency exponent. The conductivity in the direct regime, sigma(dc), is described by the small polaron model. The electrical conductivity and dielectric properties show that Hunt's model is well adapted to a-WO3 films. (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:4137 / 4142
页数:6
相关论文
共 57 条
[1]  
AGNIBORTY SA, 1986, IND J PURE APPL PHYS, V24, P9
[2]   REVIEW OF SOLID-STATE ELECTROCHROMIC COATINGS PRODUCED USING SOL-GEL TECHNIQUES [J].
AGRAWAL, A ;
CRONIN, JP ;
ZHANG, R .
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 1993, 31 (01) :9-21
[3]   Characterization of tungsten oxide films of different crystallinity prepared by RF sputtering [J].
Akl, AA ;
Kamal, H ;
Abdel-Hady, K .
PHYSICA B-CONDENSED MATTER, 2003, 325 (1-4) :65-75
[4]   Structural and optical characterization of amorphous and crystalline evaporated WO3 layers [J].
Antonaia, A ;
Polichetti, T ;
Addonizio, ML ;
Aprea, S ;
Minarini, C ;
Rubino, A .
THIN SOLID FILMS, 1999, 354 (1-2) :73-81
[5]   POLARONS IN CRYSTALLINE AND NON-CRYSTALLINE MATERIALS [J].
AUSTIN, IG ;
MOTT, NF .
ADVANCES IN PHYSICS, 1969, 18 (71) :41-+
[6]   Preparation and characterization of transparent ZnO thin films obtained by spray pyrolysis [J].
Ayouchi, R ;
Leinen, D ;
Martín, F ;
Gabas, M ;
Dalchiele, E ;
Ramos-Barrado, JR .
THIN SOLID FILMS, 2003, 426 (1-2) :68-77
[7]   ELECTROCHROMISM OF COLLOIDAL TUNGSTEN-OXIDE [J].
CHEMSEDDINE, A ;
MORINEAU, R ;
LIVAGE, J .
SOLID STATE IONICS, 1983, 9-10 (DEC) :357-361
[8]   INTERNAL-FRICTION OF ALKALINE-EARTH IRON META-PHOSPHATE GLASSES [J].
CHOMKA, W ;
SAMATOWICZ, D .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 1983, 57 (02) :327-337
[9]   OPTICAL AND PHOTOELECTRIC PROPERTIES AND COLOR CENTERS IN THIN-FILMS OF TUNGSTEN OXIDE [J].
DEB, SK .
PHILOSOPHICAL MAGAZINE, 1973, 27 (04) :801-822
[10]   INFLUENCE OF THERMAL-TREATMENT ON THE PHOTOELECTROCHEMICAL BEHAVIOR OF WO3 PHOTOANODES ELECTROCHEMICALLY GROWN [J].
DIQUARTO, F ;
DIPAOLA, A ;
PIAZZA, S ;
SUNSERI, C .
SOLAR ENERGY MATERIALS, 1985, 11 (5-6) :419-433