| Texto completo | |
| Autor(es): |
Garcia, S.
;
Andrade, S.
;
Jardim, R. F.
;
Fonseca, F. C.
;
Torikachvili, M. S.
;
Lacerda, A. H.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICAL REVIEW B; v. 80, n. 13, p. 6-pg., 2009-10-01. |
| Resumo | |
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) | |
| Processo FAPESP: | 07/51458-6 - Sergio Garcia Garcia | pessoa física - Brasil |
| Beneficiário: | Renato de Figueiredo Jardim |
| Modalidade de apoio: | Auxílio à Pesquisa - Pesquisador Visitante - Brasil |
| Processo FAPESP: | 05/53241-9 - Estudo de fenômenos intergranulares em materiais cerâmicos |
| Beneficiário: | Reginaldo Muccillo |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |