Hopping conductivity in CaCu(2)O(3) single crystals.
J Phys Condens Matter
; 18(37): 8541-9, 2006 Sep 20.
Article
em En
| MEDLINE
| ID: mdl-21690907
ABSTRACT
The resistivity, ρ, of the spin-ladder compound CaCu(2)O(3) is investigated between Tâ¼130-450 K. The ρ(T) data measured for [Formula see text] (along the Cu-O-Cu leg) and [Formula see text] (along the Cu-O-Cu rungs), ρ(a)(T)>ρ(b)(T), exhibit an activated dependence, similar in both directions and characterized by a nearest-neighbour hopping followed by a variable-range hopping (VRH) regime when T is decreased. A detailed analysis of ρ(T) demonstrates that conventional d-dimensional models of the hopping conductivity, based on the electron localization in disordered systems, cannot interpret the experimental data at any d = 1, 2 or 3, leading to the mismatch of the characteristic energies and/or unphysical values of the characteristic length scales. The observed VRH conductivity law on the low-temperature interval, lnρâ¼T(-3/4), contradicts the models above, too. Instead, it is found that this law can be substantiated and the correct matching of the energy and length scales can be found within a model of Fogler et al (2004 Phys. Rev. B 69 035413) by treating CaCu(2)O(3) as a three-dimensional array of quasi-one-dimensional electron crystals.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Phys Condens Matter
Assunto da revista:
BIOFISICA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Moldávia