We performed point-contact spectroscopy (PCS) measurements in polycrystalline RuSr2GdCu2O8 samples. The best conductance curves were obtained by using a metallic tip (Pt-Ir) pressed against the sample surface. The low-temperature conductance curves feature a zero-bias peak, suggestive of Andreev reflection at the interface between a normal metal and a d-wave superconductor. These curves can be easily fitted, in the framework of the generalized BTK model, by using pure d-wave symmetry. We were able to obtain the whole temperature dependence of the conductance curves from 4.2 K up to the critical temperature of the junction. The gap amplitude given by the fit presents an anomalous positive curvature in the whole temperature range. (c) 2005 Elsevier Ltd. All rights reserved.
Andreev-reflection measurements in RuSr2GdCu2O8
Masini R;Ferretti M
2006
Abstract
We performed point-contact spectroscopy (PCS) measurements in polycrystalline RuSr2GdCu2O8 samples. The best conductance curves were obtained by using a metallic tip (Pt-Ir) pressed against the sample surface. The low-temperature conductance curves feature a zero-bias peak, suggestive of Andreev reflection at the interface between a normal metal and a d-wave superconductor. These curves can be easily fitted, in the framework of the generalized BTK model, by using pure d-wave symmetry. We were able to obtain the whole temperature dependence of the conductance curves from 4.2 K up to the critical temperature of the junction. The gap amplitude given by the fit presents an anomalous positive curvature in the whole temperature range. (c) 2005 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
