LOCALIZATION AND ITS ABSENCE - A NEW METALLIC STATE FOR CONDUCTING POLYMERS

被引:274
作者
PHILLIPS, P
WU, HL
机构
[1] Department of Chemistry, Massachusetts Institute of Technology, Cambridge
关键词
D O I
10.1126/science.252.5014.1805
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
A widely held view in solid-state physics is that disorder precludes the presence of long-range transport in one dimension. A series of models has been recently proposed that do not conform to this view. The primary model is the random dimer model, in which the site energies for pairs of lattice sites along a linear chain are assigned one of two values at random. This model has a set of conducting states that ultimately allow an initially localized particle to move through the lattice almost ballistically. This model is applicable to the insulator-metal transition in a wide class of conducting polymers, such as polyaniline and heavily doped polyacetylene. Calculations performed on polyaniline demonstrate explicitly that the conducting states of the random dimer model for polyaniline are coincident with recent calculations of the location of the Fermi level in the metallic regime. A random dimer analysis on polyparaphenylene also indicates the presence of a set of conducting states in the vicinity of the band edge. The implications of this model for the metallic state in other polymers, including heavily doped polyacetylene, are discussed.
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页码:1805 / 1812
页数:8
相关论文
共 56 条
[41]   HOPPING CONDUCTIVITY IN GRANULAR METALS [J].
SHENG, P ;
ABELES, B ;
ARIE, Y .
PHYSICAL REVIEW LETTERS, 1973, 31 (01) :44-47
[42]  
Skotheim T. A., 1986, HDB CONDUCTING POLYM
[43]   OFF-DIAGONAL DISORDER IN ONE-DIMENSIONAL SYSTEMS [J].
SOUKOULIS, CM ;
ECONOMOU, EN .
PHYSICAL REVIEW B, 1981, 24 (10) :5698-5702
[44]  
STREITWIESER A, 1961, MOLECULAR ORBITAL TH, P135
[45]   SOLITON EXCITATIONS IN POLYACETYLENE [J].
SU, WP ;
SCHRIEFFER, JR ;
HEEGER, AJ .
PHYSICAL REVIEW B, 1980, 22 (04) :2099-2111
[46]   ELECTRONIC-STRUCTURE OF POLYIMINOVINYLENE AS A TRACTABLE MODEL FOR POLYANILINE [J].
TANAKA, K ;
SHICHIRI, T ;
KOBASHI, M ;
YAMABE, T .
SYNTHETIC METALS, 1988, 24 (03) :167-178
[47]   COMPARISON OF THE SPECIFIC-HEAT AND CONDUCTIVITY OF SI-P [J].
THOMAS, GA ;
OOTUKA, Y ;
KOBAYASHI, S ;
SASAKI, W .
PHYSICAL REVIEW B, 1981, 24 (08) :4886-4888
[48]   MAXIMUM METALLIC RESISTANCE IN THIN WIRES [J].
THOULESS, DJ .
PHYSICAL REVIEW LETTERS, 1977, 39 (18) :1167-1169
[49]   NONOHMIC CONDUCTIVITY - A PROBE OF THE LOCALIZATION MECHANISM IN POLYANILINE DERIVATIVES [J].
WANG, ZH ;
EHRENFREUND, E ;
RAY, A ;
MACDIARMID, AG ;
EPSTEIN, AJ .
MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 1990, 189 :263-272
[50]   REPULSIVE BINARY-ALLOYS AND THE ABSENCE OF LOCALIZATION - APPLICATION TO FIBONACCI LATTICES AND MOLECULARLY BASED ELECTRONIC FILTERS [J].
WU, HL ;
PHILLIPS, PW .
JOURNAL OF CHEMICAL PHYSICS, 1990, 93 (10) :7369-7373