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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Logarithmic contribution to the electrical resistivity in (Ru1-xIrx)Sr2GdCu2O8 compounds

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Garcia, S. [1, 2] ; Andrade, S. [1] ; Jardim, R. F. [1] ; Fonseca, F. C. [3] ; Torikachvili, M. S. [4] ; Lacerda, A. H. [5]
Total Authors: 6
[1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil
[2] Univ Fed Rio de Janeiro, Inst Fis, BR-21941972 Rio De Janeiro - Brazil
[3] IPEN CNEN SP, BR-05508000 Sao Paulo - Brazil
[4] San Diego State Univ, Dept Phys, San Diego, CA 92182 - USA
[5] Los Alamos Natl Lab, Los Alamos, NM 87545 - USA
Total Affiliations: 5
Document type: Journal article
Source: Physical Review B; v. 80, n. 13 OCT 2009.
Web of Science Citations: 2

A systematic study of magnetoresistance and dc magnetization was conducted in polycrystalline (Ru1-xIrx)Sr2GdCu2O8 {[}(Ru,Ir)-1212] compounds, for 0 <= x <= 0.15. We found that a deviation from linearity in the normal-state electrical resistivity (rho) curves for temperatures below the magnetic transition temperature T-M < 130 K can be properly described by a logarithmic term. The prefactor C(x, H) of this anomalous ln T contribution to rho(T) increases linearly with the Ir concentration, and diminishes rapidly with increasing applied magnetic field up to H approximate to 4 T, merging with the C(0,H) curve at higher magnetic fields. Correlation with magnetic susceptibility measurements supports a scenario of local perturbations in the orientation of Ru moments induced in the neighborhood of the Ir ions, therefore acting as scattering centers. The linear dependence of the prefactor C(x,H=0) and the superconducting transition temperature T-SC on x points to a common source for the resistivity anomaly and the reduction in T-SC, suggesting that the CuO2 and RuO2 layers are not decoupled. (AU)

FAPESP's process: 05/53241-9 - Study of intergranular phenomena in ceramic materials
Grantee:Reginaldo Muccillo
Support type: Research Projects - Thematic Grants