We report on electrical transport measurements and voltage-noise analysis in unreduced Nd1.83Ce0.17CuO4+d thin films. At low temperatures (T<100 K) the resistivity behavior is characterized by a metal-insulator crossover, which in these materials is usually interpreted in terms of weak localization induced by excess oxygen ions randomly distributed on apical impurity sites. The low-frequency voltage-spectral density reveals the presence of different conduction mechanisms in the metallic and in the insulating regions. Standard resistance fluctuations explain well the 1/ f noise at temperatures above the resistance minimum while an unusual linear dependence of the 1/ f noise on the applied bias current is found at lower temperatures, which could be interpreted as a signature of the occurrence of weak localization.
Weak localization and 1/f noise in Nd1.83Ce0.17CuO4+δ thin films
Barone C.
Writing – Original Draft Preparation
;Guarino A.Membro del Collaboration Group
;Nigro A.Membro del Collaboration Group
;Romano A.Formal Analysis
;Pagano S.Writing – Review & Editing
2009-01-01
Abstract
We report on electrical transport measurements and voltage-noise analysis in unreduced Nd1.83Ce0.17CuO4+d thin films. At low temperatures (T<100 K) the resistivity behavior is characterized by a metal-insulator crossover, which in these materials is usually interpreted in terms of weak localization induced by excess oxygen ions randomly distributed on apical impurity sites. The low-frequency voltage-spectral density reveals the presence of different conduction mechanisms in the metallic and in the insulating regions. Standard resistance fluctuations explain well the 1/ f noise at temperatures above the resistance minimum while an unusual linear dependence of the 1/ f noise on the applied bias current is found at lower temperatures, which could be interpreted as a signature of the occurrence of weak localization.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
