The Non-Adiabatic Polaron Model Revisited - BV FAPESP
Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Non-Adiabatic Polaron Model Revisited

Full text
Author(s):
Ramirez, Fabian E. N. [1] ; Souza, Jose Antonio [1]
Total Authors: 2
Affiliation:
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09090400 Santo Andre, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Brazilian Journal of Physics; v. 44, n. 4, p. 308-314, AUG 2014.
Web of Science Citations: 2
Abstract

We revisit Holstein's polaron model to derive an extension of the expression for the thermal dependence of the electrical resistivity in the non-adiabatic small-polaron regime. Our analysis relaxes Holstein's assumption that the vibrational-mode energies are much smaller than the thermal energy k (B) T and substitutes a fifth-order expansion in powers of for the linear approximation in the expression for the quasiparticle hopping probability in the original treatment. The resulting expression for the electrical resistivity has the form rho(T)=rho (0) T (3/2) exp(E (a) /k (B) T-C/T (3)+D/T (5)), where C and D are constants related to the molecule-electron interaction energy, or alternatively to the polaron binding energy, and the dispersion relation of the vibrational normal modes. We show that experimental data for the La (1-x) Ca (x) MnO (3) (x=0.30,0.34,0.40, and 0.45) manganite system, which are poorly fitted by the conventional non-adiabatic model, are remarkably well described by the more accurate expression. Our results suggest that, under conditions favoring high resistivity, the higher-order terms associated with the constants C and D in the above expression should taken into account in comparisons between theoretical and experimental results for the temperature-dependent transport properties of transition-metal oxides. (AU)

FAPESP's process: 09/18618-5 - Synthesis and characterization of thermodynamic and electrical transport properties of advanced materials
Grantee:José Antonio Souza
Support Opportunities: Regular Research Grants
FAPESP's process: 10/18364-0 - Physical properties and critical phenomena in strong correlated systems.
Grantee:Fabian Enrique Nima Ramirez
Support Opportunities: Scholarships in Brazil - Doctorate