DECREASE OF ELECTRONIC COHERENCE LENGTH BY IMPURITIES IN THE QUASI-ONE-DIMENSIONAL CHARGE-TRANSFER SALT QN(TCNQ)2

被引:10
作者
HOLCZER, K
MIHALY, G
GRUNER, G
JANOSSY, A
机构
[1] Central Research Institute for Physics, H-1525 Budapest
来源
JOURNAL OF PHYSICS C-SOLID STATE PHYSICS | 1979年 / 12卷 / 10期
关键词
D O I
10.1088/0022-3719/12/10/019
中图分类号
O469 [凝聚态物理学];
学科分类号
070205 ;
摘要
Transport properties of the quasi-one-dimensional salt Qn(TCNQ)2 with various percentages of impurity content were measured in the temperature range 4.2-330K. Nominally pure samples show a broad maximum of the conductivity at high temperatures and a large dispersion of the conductivity at 9.1 GHz. The 9.1 GHz dielectric constant has a maximum value epsilon max=3500 at 240K and epsilon 4.2=420. In samples having a 7% impurity content (disrupting the TCNQ chains) the DC conductivity is strongly decreased, no maximum of conductivity appears and the dielectric constant is also depressed, epsilon max=450 and epsilon 4.2=130. An analysis is presented in which it is assumed that electrons move coherently in highly-conducting large segments interrupted by defects. Coherence lengths (l) are estimated from the temperature dependence of the dielectric constant. A decrease from l=110 lattice constants for the pure sample to l=16 for the most impure sample corresponds well to the impurity content of 7%.
引用
收藏
页码:1883 / 1889
页数:7
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